[REF] web, *: redesign all JS views

This commit introduce a full redesign of all JS views.  We started
basically from scratch.  The goal was to unify all the various views
under a common framework, to make them testable, to make then usable in
different conditions (in studio, or in the frontend), and to make our
lives easier.

Some important points are:
- we introduced new coding guidelines (camelCase, 80 chars width, ...)
- we have a brand new testing framework (still QUnit based)
- kanban view moved to the web addon
- calendar view (formerly web_calender) moved to web as well
- the tree view was removed
- all new code should be documented

We hope that this code is the start of a new era for the Odoo web
client, we want to have a high quality codebase, well documented, well
tested, well designed.

Work done by the framework team: mostly aab, ged, chm, dmo, qsm

1 files changed, 1996 insertions, 0 deletions

diff --git a/addons/web/static/src/js/views/basic/basic_model.js b/addons/web/static/src/js/views/basic/basic_model.js
new file mode 100644
index 00000000000..5baf65f1c30
--- /dev/null
+++ b/addons/web/static/src/js/views/basic/basic_model.js
@@ -0,0 +1,1996 @@
+odoo.define('web.BasicModel', function (require) {
+"use strict";
+
+/**
+ * Basic Model
+ *
+ * This class contains all the logic necessary to communicate between the
+ * python models and the web client. More specifically, its job is to give a
+ * simple unified API to the rest of the web client (in particular, the views and
+ * the field widgets) to query and modify actual records in db.
+ *
+ * From a high level perspective, BasicModel is essentially a hashmap with
+ * integer keys and some data and metadata object as value.  Each object in this
+ * hashmap represents a piece of data, and can be reloaded and modified by using
+ * its id as key in many methods.
+ *
+ * Here is a description of what those data point look like:
+ * {
+ *    _changes: {
+ *        data: { fieldName: field_values |  [commands] },
+ *        relational_data: { field_names: datapoint }
+ *    },
+ *    aggregate_values: { fieldName: number} | undefined
+ *    count: number, default=0,
+ *    context: {string:value},
+ *    data: {string:value} | [{string:value}],
+ *    field_names: [string],
+ *    fields: {string:field description},
+ *    grouped_by: [strings] | undefined,
+ *    id: number,
+ *    is_group: boolean,
+ *    is_list: boolean,
+ *    is_open: boolean,
+ *    is_record: boolean,
+ *    limit: number | undefined (default=80 for lists)
+ *    model: string,
+ *    offset: number, default=0,
+ *    openGroupByDefault: boolean,
+ *    ordered_by: [order] | undefined,
+ *    res_id: [number]|undefined,
+ *    res_ids: [number] | undefined,
+ *    relational_data: {
+ *      field_names: datapoints
+ *    },
+ *    static: boolean,  * like previous DatasetStatic
+ * }
+ *
+ * Notes:
+ * - id: is totally unrelated to res_id.  id is a web client local concept
+ * - res_id: if set to a number, it is an actual id for a record in the server
+ *     database. If set to 'virtual_' + number, it is a record not yet saved (so,
+ *     in create mode).
+ * - res_ids: if set, it represent the context in which the data point is actually
+ *     used.  For example, a given record in a form view (opened from a list view)
+ *     might have a res_id = 2 and res_ids = [1,2,3]
+ * - offset: this is mainly used for pagination.  Useful when we need to load
+ *     another page, then we can simply change the offset and reload.
+ * - count is basically the number of records being manipulated.  We can't use
+ *     res_ids, because we might have a very large number of records, or a
+ *     domain, and the res_ids would be the current page, not the full set.
+ * - model is the actual name of a (odoo) model, such as 'res.partner'
+ * - fields contains the description of all the fields from the model.  Note that
+ *     these properties might have been modified by a view (for example, with
+ *     required=true.  So, the fields kind of depends of the context of the
+ *     data point.
+ * - field_names: list of some relevant field names (string).  Usually, it
+ *     denotes the fields present in the view.  Only those fields should be
+ *     loaded.
+ * - _cache and _changes are private, they should not leak out of the basicModel
+ *   and be used by anyone else.
+ *
+ * Commands:
+ *   commands are the base commands for x2many (0 -> 6), but with a
+ *   slight twist: each [0, _, values] command is augmented with a virtual id:
+ *   it means that when the command is added in basicmodel, it generates an id
+ *   looking like this: 'virtual_' + number, and uses this id to identify the
+ *   element, so it can be edited later.
+ */
+
+var AbstractModel = require('web.AbstractModel');
+var concurrency = require('web.concurrency');
+var data = require('web.data'); // TODO: remove dependency to data.js
+var pyeval = require('web.pyeval');
+var session = require('web.session');
+
+var x2ManyCommands = {
+    // (0, _, {values})
+    CREATE: 0,
+    create: function (values) {
+        return [x2ManyCommands.CREATE, false, values];
+    },
+    // (1, id, {values})
+    UPDATE: 1,
+    update: function (id, values) {
+        return [x2ManyCommands.UPDATE, id, values];
+    },
+    // (2, id[, _])
+    DELETE: 2,
+    delete: function (id) {
+        return [x2ManyCommands.DELETE, id, false];
+    },
+    // (3, id[, _]) removes relation, but not linked record itself
+    FORGET: 3,
+    forget: function (id) {
+        return [x2ManyCommands.FORGET, id, false];
+    },
+    // (4, id[, _])
+    LINK_TO: 4,
+    link_to: function (id) {
+        return [x2ManyCommands.LINK_TO, id, false];
+    },
+    // (5[, _[, _]])
+    DELETE_ALL: 5,
+    delete_all: function () {
+        return [5, false, false];
+    },
+    // (6, _, ids) replaces all linked records with provided ids
+    REPLACE_WITH: 6,
+    replace_with: function (ids) {
+        return [6, false, ids];
+    }
+};
+
+var Model = AbstractModel.extend({
+    /**
+     * @override
+     */
+    init: function () {
+        // this mutex is necessary to make sure some operations are done
+        // sequentially, for example, an onchange needs to be completed before a
+        // save is performed.
+        this.mutex = new concurrency.Mutex();
+
+        // this dictionary is used to hold all many2one informations for widget
+        // selection.
+        this.many2ones = {};
+
+        // this dictionary is used to hold all many2many informations for widget
+        // many2many_checkboxes.
+        this.many2manys = {};
+
+        this.localData = Object.create(null);
+        this._super.apply(this, arguments);
+    },
+
+    //--------------------------------------------------------------------------
+    // Public
+    //--------------------------------------------------------------------------
+
+
+    /**
+     * Add a default record to a list object.  This method actually make a new
+     * record with the makeDefaultRecord method, then add it to the list object.
+     *
+     * @param {string} listID a valid handle for a list object
+     * @param {Object} [options]
+     * @param {string} [options.position=top] if the new record should be added
+     *   on top or on bottom of the list
+     * @returns {Deferred<string>} resolves to the id of the new created record
+     */
+    addDefaultRecord: function (listID, options) {
+        var list = this.localData[listID];
+        var context = this._getContext(list);
+
+        var position = (options && options.position) || 'top';
+        var params = {
+            context: context,
+            fieldAttrs: list.fieldAttrs,
+            fieldNames: list.fieldNames,
+            fields: list.fields,
+        };
+        return this.makeDefaultRecord(list.model, params).then(function(id) {
+            list.count++;
+            if (position === 'top') {
+                list.data.unshift(id);
+            } else {
+                list.data.push(id);
+            }
+            return id;
+        });
+    },
+    /**
+     * Delete a list of records, then, if a parent_id is given, reload the
+     * parent.
+     *
+     * @todo we should remove the deleted records from the localData
+     * @todo is it really necessary to reload the data? it seems artificial, and
+     *   the caller should be able to do that himself
+     * @todo why can't we infer modelName?
+     *
+     * @param {string[]} recordIds list of local resources ids. They should all
+     *   be of type 'record', and of the same model
+     * @param {string} modelName
+     * @param {string} parent_id
+     * @returns {Deferred}
+     */
+    deleteRecords: function (recordIds, modelName, parent_id) {
+        var self = this;
+        var records = _.map(recordIds, function (id) { return self.localData[id]; });
+        return this.performModelRPC(modelName, 'unlink', [_.pluck(records, 'res_id')], {
+            context: session.user_context, // todo: combine with view context
+        }).then(function () {
+            _.each(records, function (record) {
+                record.res_ids.splice(record.offset, 1)[0];
+                record.res_id = record.res_ids[record.offset];
+                record.count--;
+            });
+            if (parent_id) {
+                return self.reload(parent_id);
+            }
+        });
+    },
+    /**
+     * Discard all changes in a local resource.  Basically, it removes
+     * everything that was stored in a _changes key.
+     *
+     * @param {string} id local resource id
+     */
+    discardChanges: function (id) {
+        var element = this.localData[id];
+        this._visitChildren(element, function (elem) {
+            elem._changes = null;
+        });
+    },
+    /**
+     * Duplicate a record (by calling the 'copy' route)
+     *
+     * @param {string} recordID id for a local resource
+     * @returns {Deferred -> string} resolves to the id of duplicate record
+     */
+    duplicateRecord: function (recordID) {
+        var self = this;
+        var record = this.localData[recordID];
+        return this.performModelRPC(record.model, 'copy', [record.data.id], {
+            context: this._getContext(record),
+        }).then(function (res_id) {
+            var index = record.res_ids.indexOf(record.res_id);
+            record.res_ids.splice(index + 1, 0, res_id);
+            return self.load({
+                fieldAttrs: record.fieldAttrs,
+                fieldNames: record.fieldNames,
+                fields: record.fields,
+                modelName: record.model,
+                res_id: res_id,
+                res_ids: record.res_ids.slice(0),
+            });
+        });
+    },
+    /**
+     * The get method first argument is the handle returned by the load method.
+     * It is optional (the handle can be undefined).  In some case, it makes
+     * sense to use the handle as a key, for example the BasicModel holds the
+     * data for various records, each with its local ID.
+     *
+     * synchronous method, it assumes that the resource has already been loaded.
+     *
+     * @param {string} id local id for the resource
+     * @param {any} options
+     * @param {boolean} [options.env=false] if true, will only  return res_id
+     *   (if record) or res_ids (if list)
+     * @param {boolean} [options.raw=false] if true, will not follow relations
+     * @returns {Object}
+     */
+    get: function (id, options) {
+        var self = this;
+        options = options || {};
+
+        if (!(id in this.localData)) {
+            return null;
+        }
+
+        var record = this.localData[id];
+
+        if (options.env) {
+            var env = {
+                ids: record.res_ids ? record.res_ids.slice(0) : [],
+            };
+            if (record.type === 'record') {
+                env.currentId = this.isNew(record.id) ? undefined : record.res_id;
+            }
+            return env;
+        }
+
+        // do not copy fields: this has a really big performance cost, for views
+        // with many records and lots of fields (for ex, kanban view contacts)
+        var fields = record.fields;
+        delete record.fields;
+        var element = $.extend(true, {}, record);
+        record.fields = fields;
+        element.fields = fields;
+
+        var field, relDataPoint;
+        if (element.type === 'record') {
+            // apply changes
+            _.extend(element.data, element._changes);
+
+            for (var fieldName in element.data) {
+                field = element.fields[fieldName];
+
+                // get relational datapoint
+                if (field.type === 'many2one') {
+                    if (options.raw) {
+                        relDataPoint = this.localData[element.data[fieldName]];
+                        element.data[fieldName] = relDataPoint ? relDataPoint.res_id : false;
+                    } else {
+                        element.data[fieldName] = this.get(element.data[fieldName]) || false;
+                    }
+                }
+                if (field.type === 'one2many' || field.type === 'many2many') {
+                    if (options.raw) {
+                        relDataPoint = this.localData[element.data[fieldName]];
+                        var ids = _.map(relDataPoint.data, function (id) {
+                            return self.localData[id].res_id;
+                        });
+                        element.data[fieldName] = ids;
+                    } else {
+                        element.data[fieldName] = this.get(element.data[fieldName]) || [];
+                    }
+                }
+
+                // weird way to get out many2ones for widget=selection
+                if (field.__fetch_selection) {
+                    field.__selection_information = self.many2ones[field.relation];
+                }
+
+                // weird way to get out many2manys for widget=many2many_checkboxes
+                if (field.__fetch_many2manys) {
+                    field.__many2many_information = self.many2manys[field.relation];
+                }
+            }
+
+            // this is not strictly necessary, but it hides some implementation
+            // details, and can easily be removed if needed.
+            delete element.orderedBy;
+            delete element.aggregateValues;
+            delete element.groupedBy;
+        }
+        if (element.type === 'list') {
+            // apply changes if any
+            if (element._changes) {
+                element.data = element._changes;
+                element.count = element._changes.length;
+                element.res_ids = _.map(element._changes, function (elemID) {
+                    return self.localData[elemID].res_id;
+                });
+            }
+            // get relational datapoint
+            element.data = _.map(element.data, function (elemID) {
+                return self.get(elemID);
+            });
+        }
+
+        delete element._cache;
+        delete element._changes;
+        delete element.static;
+        delete element.parentID;
+        delete element.rawContext;
+        return element;
+    },
+    /**
+     * return true if a record is dirty. A record is considered dirty if it has
+     * some unsaved changes. A list is considered dirty if its _changes key is
+     * set to an array of its new datapoints (possibly empty)
+     *
+     * @param {string} id id for a local resource
+     * @returns {boolean}
+     */
+    isDirty: function (id) {
+        var isDirty = false;
+        var record = this.localData[id];
+        this._visitChildren(record, function (r) {
+            if (r.type === "record" ? !_.isEmpty(r._changes) : r._changes) {
+                isDirty = true;
+            }
+        });
+        return isDirty;
+    },
+    /**
+     * Check if a record is new, meaning if it is in the process of being
+     * created and no actual record exists in db.
+     *
+     * @param {string} id id for a local resource
+     * @returns {boolean}
+     */
+    isNew: function (id) {
+        return typeof this.localData[id].res_id !== 'number';
+    },
+    /**
+     * Main entry point, the goal of this method is to fetch and process all
+     * data (following relations if necessary) for a given record/list.
+     *
+     * @todo document all params
+     *
+     * @param {any} params
+     * @param {Object} [params.fieldAttrs={}] contains the attrs of each field
+     * @param {Array} [params.fieldNames] the name of fields to load, the list
+     *   of all fields by default
+     * @param {Object} params.fields contains the description of each field
+     * @param {string} [params.type] 'record' or 'list'
+     * @returns {Deferred -> string} resolves to a local id, or handle
+     */
+    load: function (params) {
+        params.type = params.type || (params.res_id !== undefined ? 'record' : 'list');
+
+        if (params.type === 'record' && params.res_id === undefined) {
+            return this.makeDefaultRecord(params.modelName, params);
+        }
+        var dataPoint = this._makeDataPoint(params);
+        return this._load(dataPoint).then(function () {
+            return dataPoint.id;
+        });
+    },
+    /**
+     * When one needs to create a record from scratch, a not so simple process
+     * needs to be done:
+     * - call the /default_get route to get default values
+     * - fetch all relational data
+     * - apply all onchanges if necessary
+     * - fetch all relational data
+     *
+     * This method tries to optimize the process as much as possible.  Also,
+     * it is quite horrible and should be refactored at some point.
+     *
+     * @param {any} params
+     * @param {string} modelName model name
+     * @param {Object} params.context the context for the new record
+     * @param {Object} [params.fieldAttrs={}] contains the attrs of each field
+     * @param {Array} params.fieldNames the name of fields to load, the list
+     *   of all fields by default
+     * @param {Object} params.fields contains the description of each field
+     * @param {Object} params.context the context for the new record
+     * @returns {Deferred -> string} resolves to the id for the created resource
+     */
+    makeDefaultRecord: function (modelName, params) {
+        var self = this;
+        var fields_key = _.without(params.fieldNames, '__last_update');
+
+        return this.performModelRPC(modelName, 'default_get', [fields_key], {
+            context: params.context,
+        }).then(function (result) {
+            // fill default values for missing fields
+            for (var i = 0; i < params.fieldNames.length; i++) {
+                var fieldName = params.fieldNames[i];
+                if (!(fieldName in result)) {
+                    var field = params.fields[fieldName];
+                    if (field.type === 'one2many' || field.type === 'many2many') {
+                        result[fieldName] = [];
+                    } else {
+                        result[fieldName] = null;
+                    }
+                }
+            }
+
+            var data = {};
+            var record = self._makeDataPoint({
+                modelName: modelName,
+                data: data,
+                fields: params.fields,
+                fieldNames: params.fieldNames,
+                fieldAttrs: params.fieldAttrs,
+                context: params.context,
+                res_ids: params.res_ids,
+            });
+
+            var defs = [];  // FIXME: remove defs?
+            _.each(params.fieldNames, function (name) {
+                var field = params.fields[name];
+                data[name] = null;
+                record._changes = record._changes || {};
+                if (field.type === 'many2one' && result[name]) {
+                    var rec = self._makeDataPoint({
+                        context: record.context,
+                        data: {id: result[name]},
+                        modelName: field.relation,
+                    });
+                    record._changes[name] = rec.id;
+                } else if (field.type === 'one2many' || field.type === 'many2many') {
+                    var x2manyList = self._makeDataPoint({
+                        context: record.context,
+                        fieldAttrs: field.fieldAttrs,
+                        fields: field.relatedFields,
+                        limit: field.limit,
+                        modelName: field.relation,
+                        res_ids: [],
+                        static: true,
+                        type: 'list',
+                    });
+                    record._changes[name] = x2manyList.id;
+                    var many2ones = {};
+                    _.each(result[name], function (command) {
+                        if (command[0] === 0) {
+                            // CREATE
+                            var r = self._makeDataPoint({
+                                modelName: x2manyList.model,
+                                context: x2manyList.context,
+                                fields: field.relatedFields,
+                                fieldAttrs: field.fieldAttrs,
+                            });
+                            x2manyList._changes.push(r.id);
+                            r._changes = command[2];
+
+                            // this is necessary so the fields are initialized
+                            for (var fieldName in command[2]) {
+                                r.data[fieldName] = null;
+                            }
+
+                            for (var name in r._changes) {
+                                if (r.fields[name].type === 'many2one') {
+                                    var rec = self._makeDataPoint({
+                                        context: r.context,
+                                        modelName: r.fields[name].relation,
+                                        data: {id: r._changes[name]}
+                                    });
+                                    r._changes[name] = rec.id;
+                                    many2ones[name] = true;
+                                }
+                            }
+                        }
+                        if (command[0] === 6) {
+                            // REPLACE_WITH
+                            x2manyList._changes = [];
+                        }
+                    });
+
+                    // fetch many2ones display_name
+                    _.each(_.keys(many2ones), function (name) {
+                        defs.push(self._fetchNameGets(x2manyList, name));
+                    });
+                } else {
+                    record._changes[name] = result[name];
+                }
+            });
+            return $.when.apply($, defs)
+                .then(function () {
+                    var shouldApplyOnchange = false;
+                    var field;
+                    for (var field_name in record.data) {
+                        field = record.fields[field_name];
+                        if (field.onChange) {
+                            shouldApplyOnchange = true;
+                        }
+                    }
+                    if (shouldApplyOnchange) {
+                        return self._applyOnChange(record, fields_key);
+                    } else {
+                        return $.when();
+                    }
+                })
+                .then(function () {
+                    return self._fetchRelationalData(record);
+                })
+                .then(function () {
+                    return self._postprocess(record);
+                })
+                .then(function () {
+                    return record.id;
+                });
+        });
+    },
+    /**
+     * This helper method is designed to help developpers that want to use a
+     * field widget outside of a view.  In that case, we want a way to create
+     * data without actually performing a fetch.
+     *
+     * @param {string} model name of the model
+     * @param {Object[]} fields a description of field properties
+     * @param {Object} [attrs] various field attrs that we want to set
+     * @returns {string} the local id for the created resource
+     */
+    makeRecord: function (model, fields, attrs) {
+        var self = this;
+        var record_fields = {};
+        _.each(fields, function (field) {
+            record_fields[field.name] = _.pick(field, 'type', 'relation', 'domain');
+        });
+        var record = this._makeDataPoint({
+            modelName: model,
+            fields: record_fields,
+            fieldAttrs: attrs,
+        });
+        _.each(fields, function (field) {
+            if ('value' in field) {
+                if (field.type === 'many2one') {
+                    var id = field.value[0];
+                    var display_name = field.value[1];
+                    var relatedRecord = self._makeDataPoint({
+                        modelName: field.relation,
+                        data: {
+                            id: id,
+                            display_name: display_name,
+                        }
+                    });
+                    record.data[field.name] = relatedRecord.id;
+                } else {
+                    record.data[field.name] = field.value;
+                }
+            }
+        });
+        return record.id;
+    },
+    /**
+     * This method just does a name_create call to the server.
+     *
+     * @todo Maybe this method should also create a local record...
+     *
+     * @param {string} model the name of the model
+     * @param {string} name the desired name of the created record
+     * @param {Object} context the context to be passed to the rpc
+     * @returns {Deferred}
+     */
+    nameCreate: function (model, name, context) {
+        return this.performModelRPC(model, 'name_create', [name], {
+            context: _.extend({}, session.user_context, context),
+        });
+    },
+    /**
+     * Do a name_search.  I think that it should be done directly by the widget
+     * @todo remove this
+     * @deprecated
+     *
+     * @param {any} model
+     * @param {any} name
+     * @param {any} domain
+     * @param {any} operator
+     * @param {any} limit
+     * @returns
+     */
+    nameSearch: function (model, name, domain, operator, limit) {
+        // fixme: correctly handle context
+        return this.performModelRPC(model, 'name_search', [], {
+            name: name || '',
+            args: domain || [],
+            operator: operator || 'ilike',
+            limit: limit || 0,
+        });
+    },
+    /**
+     * This is an extremely important method.  All changes in any field go
+     * through this method.  It will then apply them in the local state, check
+     * if onchanges needs to be applied, actually do them if necessary, then
+     * resolves with the list of changed fields.
+     *
+     * @param {string} record_id
+     * @param {Object} changes a map field => new value
+     * @returns {string[]} list of changed fields
+     */
+    notifyChanges: function (record_id, changes) {
+        var self = this;
+        var record = this.localData[record_id];
+        var onChangeFields = []; // the fields that have changed and that have an on_change
+        var field;
+        var defs = [];
+        record._changes = record._changes || {};
+
+        // apply changes to local data
+        for (var fieldName in changes) {
+            field = record.fields[fieldName];
+            if (field.type === 'one2many' || field.type === 'many2many') {
+                defs.push(this._applyX2ManyChange(record, fieldName, changes[fieldName]));
+            } else if (field.type === 'many2one') {
+                defs.push(this._applyMany2OneChange(record, fieldName, changes[fieldName]));
+            } else {
+                record._changes[fieldName] = changes[fieldName];
+            }
+            if (field.onChange) {
+                onChangeFields.push(fieldName);
+            }
+        }
+
+        return $.when.apply($, defs).then(function () {
+            var onchangeDef;
+            if (onChangeFields.length) {
+                onchangeDef = self._applyOnChange(record, onChangeFields).then(function (result) {
+                    return _.keys(changes).concat(Object.keys(result && result.value || {}));
+                });
+            } else {
+                onchangeDef = $.Deferred().resolve(_.keys(changes));
+            }
+            return onchangeDef.then(function (fieldNames) {
+                _.each(fieldNames, function (name) {
+                    if (record._changes && record._changes[name] === record.data[name]) {
+                        delete record._changes[name];
+                    }
+                });
+                return fieldNames;
+            });
+        });
+    },
+    /**
+     * Reload all data for a given resource
+     *
+     * @param {string} id local id for a resource
+     * @param {Object} [options]
+     * @returns {Deferred -> string} resolves to the id of the resource
+     */
+    reload: function (id, options) {
+        options = options || {};
+        var element = this.localData[id];
+
+        if (element.type === 'record') {
+            if ('currentId' in options && !options.currentId) {
+                var params = {
+                    context: element.context,
+                    fieldAttrs: element.fieldAttrs,
+                    fieldNames: element.fieldNames,
+                    fields: element.fields,
+                };
+                return this.makeDefaultRecord(element.model, params);
+            }
+            this.discardChanges(id);
+        }
+
+        if (options.context !== undefined) {
+            element.context = options.context;
+        }
+        if (options.domain !== undefined) {
+            element.domain = options.domain;
+        }
+        if (options.groupBy !== undefined) {
+            element.groupedBy = options.groupBy;
+        }
+        if (options.limit !== undefined) {
+            element.limit = options.limit;
+        }
+        if (options.offset !== undefined) {
+            this._setOffset(element.id, options.offset);
+        }
+        if (options.currentId !== undefined) {
+            element.res_id = options.currentId;
+        }
+        if (options.ids !== undefined) {
+            element.res_ids = options.ids;
+            element.count = element.res_ids.length;
+        }
+        if (element.type === 'record') {
+            element.offset = _.indexOf(element.res_ids, element.res_id);
+        }
+        var loadOptions = _.pick(options, 'fieldNames');
+        return this._load(element, loadOptions).then(function (result) {
+            return result.id;
+        });
+    },
+    /**
+     * Save a local resource, if needed.  This is a complicated operation,
+     * - it needs to check all changes,
+     * - generate commands for x2many fields,
+     * - call the /create or /write method according to the record status
+     * - After that, it has to reload all data, in case something changed,
+     *   server side.
+     *
+     * @param {string} record_id local resource
+     * @param {Object} [options]
+     * @param {boolean} [options.reload=true] if true, data will be reloaded
+     * @returns {Deferred}
+     */
+    save: function (record_id, options) {
+        var self = this;
+        options = options || {};
+        var shouldReload = 'reload' in options ? options.reload : true;
+        return this.mutex.exec(function () {
+            var record = self.localData[record_id];
+            var method = self.isNew(record_id) ? 'create' : 'write';
+            var changes = _.extend({}, record._changes);
+            var commands = self._generateX2ManyCommands(record);
+            for (var fieldName in commands) {
+                if (commands[fieldName] === null) {
+                    delete changes[fieldName];
+                } else {
+                    changes[fieldName] = commands[fieldName];
+                }
+            }
+
+            // replace local ids by actual ids in relational changes
+            for (fieldName in changes) {
+                var field = record.fields[fieldName];
+                if (field.type === 'many2one') {
+                    if (changes[fieldName]) {
+                        var res_id = self.localData[changes[fieldName]].res_id;
+                        changes[fieldName] = res_id;
+                    } else {
+                        changes[fieldName] = false;
+                    }
+                }
+            }
+
+            if (method === 'create') {
+                _.each(record.fieldNames, function (name) {
+                    changes[name] = changes[name] || record.data[name];
+                    if (changes[name] === null) {
+                        delete changes[name];
+                    }
+                });
+            }
+            // make sure we don't write an undefined id
+            delete changes.id;
+
+            // in the case of a write, only perform the RPC if there are changes to save
+            if (method === 'create' || Object.keys(changes).length) {
+                var args = method === 'write' ? [[record.data.id], changes] : [changes];
+                return self.performModelRPC(record.model, method, args, {
+                    context: session.user_context, // todo: combine with view context
+                }).then(function (id) {
+                    if (method === 'create') {
+                        record.res_id = id;  // create returns an id, write returns a boolean
+                        record.data.id = id;
+                        record.offset = record.res_ids.length;
+                        record.res_ids.push(id);
+                        record.count++;
+                    }
+                    // erase changes as they have been applied
+                    record._changes = {};
+
+                    return shouldReload ? self._fetchRecord(record) : false;
+                });
+            } else {
+                return $.when(record_id);
+            }
+        });
+    },
+    /**
+     * For list resources, this changes the orderedBy key, then performs the
+     * sort directly, in javascript.  This is used for sorting static datasets,
+     * such as a one2many in a form view. For dynamic datasets, such as a list
+     * view, this method will be called, but then the sort will be ignored since
+     * we will reload data.
+     *
+     * @todo don't sort in js when we reload data anyway
+     *
+     * @param {string} list_id id for the list resource
+     * @param {string} fieldName valid field name
+     * @returns {this} so we can chain call this method
+     */
+    setSort: function (list_id, fieldName) {
+        var list = this.localData[list_id];
+        if (list.type === 'record') {
+            return;
+        }
+        list.offset = 0;
+        if (list.orderedBy.length === 0) {
+            list.orderedBy.push({name: fieldName, asc: true});
+        } else if (list.orderedBy[0].name === fieldName){
+            list.orderedBy[0].asc = !list.orderedBy[0].asc;
+        } else {
+            var orderedBy = _.reject(list.orderedBy, function (o) {
+                return o.name === fieldName;
+            });
+            list.orderedBy = [{name: fieldName, asc: true}].concat(orderedBy);
+        }
+        this._sortList(list);
+        return this;
+    },
+    /**
+     * Toggle the active value of given records (to archive/unarchive them)
+     *
+     * @param {Array} recordIDs local ids of the records to (un)archive
+     * @param {boolean} value false to archive, true to unarchive (value of the active field)
+     * @param {string} parentID id of the parent resource to reload
+     * @returns {Deferred -> string} resolves to the parent id
+     */
+    toggleActive: function(recordIDs, value, parentID) {
+        var self = this;
+        var parent = this.localData[parentID];
+        var resIDs = _.map(recordIDs, function(recordID) {
+            return self.localData[recordID].res_id;
+        });
+        return this
+            .performModelRPC(parent.model, 'write', [resIDs, { active: value }])
+            .then(this.reload.bind(this, parentID));
+
+    },
+    /**
+     * Toggle (open/close) a group in a grouped list, then fetches relevant
+     * data
+     *
+     * @param {string} groupId
+     * @returns {Deferred -> string} resolves to the group id
+     */
+    toggleGroup: function (groupId) {
+        var group = this.localData[groupId];
+        if (group.isOpen) {
+            group.isOpen = false;
+            group.data = [];
+            group.offset = 0;
+            return $.when(groupId);
+        }
+        if (!group.isOpen) {
+            group.isOpen = true;
+            var def;
+            if (group.count > 0) {
+                def = this._fetchUngroupedList(group);
+            }
+            return $.when(def).then(function () {
+                return groupId;
+            });
+        }
+    },
+
+    //--------------------------------------------------------------------------
+    // Private
+    //--------------------------------------------------------------------------
+
+    /**
+     * Apply a many2one onchange.  There is a need for this function because the
+     * server only gives an id when a onchange modifies a many2one field.  For
+     * this reason, we need (sometimes) to do a /name_get to fetch a
+     * display_name.
+     *
+     * @param {Object} record
+     * @param {string} fieldName
+     * @param {Object} [data]
+     * @returns {Deferred}
+     */
+    _applyMany2OneChange: function (record, fieldName, data) {
+        var self = this;
+        if (!data) {
+            record._changes[fieldName] = false;
+            return $.when();
+        }
+        var rel_data = _.pick(data, 'id', 'display_name');
+        var def;
+        if (!('display_name' in rel_data)) {
+            var field = record.fields[fieldName];
+            def = this.performModelRPC(field.relation, 'name_get', [data.id], {
+                context: record.context,
+            }).then(function (result) {
+                rel_data.display_name = result[0][1];
+            });
+        }
+        return $.when(def).then(function () {
+            var rec = self._makeDataPoint({
+                context: record.context,
+                data: rel_data,
+                fields: {},
+                modelName: record.fields[fieldName].relation,
+            });
+            record._changes[fieldName] = rec.id;
+        });
+    },
+    /**
+     * This method is quite important: it is supposed to perform the /onchange
+     * rpc and apply the result.
+     *
+     * @param {Object} record
+     * @param {string[]} fields changed fields
+     * @returns
+     */
+    _applyOnChange: function (record, fields) {
+        var self = this;
+        var onchange_spec = this._buildOnchangeSpecs(record);
+        var idList = record.data.id ? [record.data.id] : [];
+        var context = data.build_context(record, session.user_context).eval();
+
+        var rawData = this.get(record.id, {raw: true}).data;
+        var commands = this._generateX2ManyCommands(record);
+        var currentData = _.pick(_.extend(rawData, commands), record.fieldNames);
+        if (fields.length === 1) {
+            fields = fields[0];
+        }
+        return this.mutex.exec(function () {
+            var args = [idList, currentData, fields, onchange_spec, context];
+            return self.performModelRPC(record.model, 'onchange', args, {}).then(function (result) {
+                var defs = [];
+                _.each(result.value, function (val, name) {
+                    var field = record.fields[name];
+                    if (!field) { return; } // ignore changes of unknown fields
+
+                    if (field.type === 'many2one' ) {
+                        // in some case, the value returned by the onchange can
+                        // be false (no value), so we need to avoid creating a
+                        // local record for that.
+                        // FIXME: shouldn't we erase the value in that case?
+                        if (val) {
+                            // when the value isn't false, it can be either
+                            // an array [id, display_name] or just an id.
+                            var data = _.isArray(val) ?
+                                {id: val[0], display_name: val[1]} :
+                                {id: val};
+                            var rec = self._makeDataPoint({
+                                context: context,
+                                data: data,
+                                modelName: field.relation,
+                            });
+                            record._changes[name] = rec.id;
+                        }
+                    } else if (field.type === 'one2many') {
+                        record._changes = record._changes || {};
+                        var listId = record._changes[name] || record.data[name];
+                        var list = self.localData[listId];
+                        var rec;
+                        _.each(val, function (command) {
+                            if (command[0] === 0 || command[0] === 1) {
+                                // CREATE or UPDATE
+                                var params = {
+                                    context: context,
+                                    fields: list.fields,
+                                    fieldAttrs: list.fieldAttrs,
+                                    modelName: list.model,
+                                    fieldNames: _.keys(command[2]),
+                                };
+                                if (command[0] === 1) {
+                                    params.res_id = command[1];
+                                }
+                                rec = self._makeDataPoint(params);
+                                var data = command[2];
+                                _.each(rec.fieldNames, function (name) {
+                                    var field = rec.fields[name];
+                                    if (field.type === 'many2one') {
+                                        var r = self._makeDataPoint({
+                                            modelName: field.relation,
+                                            data: {
+                                                id: data[name][0],
+                                                display_name: data[name][1],
+                                            },
+                                        });
+                                        data[name] = r.id;
+                                    }
+                                });
+                                rec._changes = data;
+                                for (var f in rec._changes) {
+                                    rec.data[f] = null;
+                                }
+                                list._changes.push(rec.id);
+                            }
+                            if (command[0] === 5) {
+                                // DELETE ALL
+                                list._changes = [];
+                            }
+                        });
+                    } else {
+                        record._changes[name] = val;
+                    }
+                });
+                return $.when.apply($, defs).then(function () {
+                    return result;
+                });
+            });
+        });
+    },
+    /**
+     * When an operation is applied to a x2many field, the field widgets
+     * generate one (or more) command, which describes the exact operation.
+     * This method tries to interpret these commands and apply them to the
+     * localData.
+     *
+     * @param {Object} record
+     * @param {string} fieldName
+     * @param {Object} command A command object.  It should have a 'operation'
+     *   key.  For example, it looks like {operation: ADD, id: 'partner_1'}
+     * @returns {Deferred}
+     */
+    _applyX2ManyChange: function (record, fieldName, command) {
+        var self = this;
+        var list = this.localData[record._changes[fieldName] || record.data[fieldName]];
+        var field = record.fields[fieldName];
+        var rec;
+        var defs = [];
+        list._changes = list._changes || list.data;
+
+        switch (command.operation) {
+            case 'ADD':
+                // for now, we are in the context of a one2many field
+                // the command should look like this:
+                // { operation: 'ADD', id: localID }
+                // The corresponding record may contain value for fields that
+                // are unknown in the list (e.g. fields that are in the
+                // subrecord form view but not in the kanban or list view), so
+                // to ensure that onchanges are correctly handled, we extend the
+                // list's fields with those in the created record
+                var newRecord = this.localData[command.id];
+                _.defaults(list.fields, newRecord.fields);
+                newRecord.fields = list.fields;
+                list._changes.push(newRecord.id);
+                break;
+            case 'ADD_M2M':
+                // handle multiple add: command[2] may be a dict of values (1
+                // record added) or an array of dict of values
+                var data = _.isArray(command.ids) ? command.ids : [command.ids];
+                var list_records = {};
+                _.each(data, function (d) {
+                    rec = self._makeDataPoint({
+                        context: record.context,
+                        modelName: field.relation,
+                        fields: field.relatedFields,
+                        fieldAttrs: field.fieldAttrs,
+                        res_id: d.id,
+                    });
+                    list_records[d.id] = rec;
+                    list._changes.push(rec.id);
+                });
+                // read list's records as we only have their ids and optionally their display_name
+                // (we can't use function readUngroupedList because those records are only in the
+                // _changes so this is a very specific case)
+                // this could be optimized by registering the fetched records in the list's _cache
+                // so that if a record is removed and then re-added, it won't be fetched twice
+                var def = this
+                    .performModelRPC(list.model, 'read', [_.pluck(data, 'id'), list.fieldNames], {})
+                    .then(function (records) {
+                        _.each(records, function (record) {
+                            list_records[record.id].data = record;
+                        });
+                    });
+                defs.push(def);
+                break;
+            case 'CREATE':
+                defs.push(this.addDefaultRecord(list.id));
+                break;
+            case 'UPDATE':
+                var changedRecord = this.localData[command.id];
+                changedRecord._changes = changedRecord._changes || {};
+                _.extend(changedRecord._changes, _.pick(command.data, list.fieldNames));
+                break;
+            case 'REMOVE':
+                list._changes = _.without(list._changes, command.id);
+                break;
+            case 'REPLACE_WITH':
+                // this is certainly not optimal... and not sure that it is
+                // correct if some ids are added and some other are removed
+                var currentIds = _.map(list._changes, function (localId) {
+                    return self.localData[localId].res_id;
+                });
+                var newIds = _.difference(command.ids, currentIds);
+                var removedIds = _.difference(currentIds, command.ids);
+                var addDef, removedDef;
+                if (newIds.length) {
+                    var values = _.map(newIds, function (id) {
+                        return {id: id};
+                    });
+
+                    addDef = this._applyX2ManyChange(record, fieldName, {
+                        operation: 'ADD_M2M',
+                        ids: values
+                    });
+                }
+                if (removedIds.length) {
+                    removedDef = this._applyX2ManyChange(record, fieldName, {
+                        operation: 'REMOVE',
+                        ids: removedIds
+                    });
+                }
+                return $.when(addDef, removedDef);
+        }
+
+        return $.when.apply($, defs);
+    },
+    /**
+     * Helper method to build a 'spec', that is a description of all fields in
+     * the view that have a onchange defined on them.
+     *
+     * An onchange spec is necessary as an argument to the /onchange route. It
+     * looks like this: { field: "1", anotherField: "", relation.subField: "1"}
+     *
+     * @see _applyOnChange
+     *
+     * @param {Object} record resource object of type 'record'
+     * @returns {Object} an onchange spec
+     */
+    _buildOnchangeSpecs: function (record) {
+        // TODO: replace this function by some generic tree function in utils
+        var specs = {};
+        _.each(record.fieldNames, function (name) {
+            var field = record.fields[name];
+            specs[name] = (field.onChange) || "";
+            _.each(field.views, function (view) {
+                _.each(view.fields, function (field, subname) {
+                    specs[name + '.' + subname] = (field.onChange) || "";
+                });
+            });
+        });
+        return specs;
+    },
+    /**
+     * Fetch all name_gets for the many2ones in a group
+     *
+     * @param {Object} group a valid resource object
+     * @returns {Deferred}
+     */
+    _fetchMany2OneGroup: function (group) {
+        var ids = _.uniq(_.pluck(group, 'res_id'));
+
+        return this.performModelRPC(group[0].model, 'name_get', [ids], {
+            context: group[0].context,
+        }).then(function (name_gets) {
+            _.each(group, function (record) {
+                var nameGet = _.find(name_gets, function (n) { return n[0] === record.res_id;});
+                record.data.display_name = nameGet[1];
+            });
+        });
+    },
+    _fetchNameGets: function (list, fieldName) {
+        var self = this;
+        var model;
+        var records = [];
+        var ids = _.map(list._changes || list.data, function (localId) {
+            var record = self.localData[localId];
+            var data = record._changes || record.data;
+            var many2oneId = data[fieldName];
+            var many2oneRecord = self.localData[many2oneId];
+            records.push(many2oneRecord);
+            model = many2oneRecord.model;
+            return many2oneRecord.res_id;
+        });
+        return this.performModelRPC(model, 'name_get', [ids], {
+            context: list.context,
+        }).then(function (name_gets) {
+            for (var i = 0; i < name_gets.length; i++) {
+                records[i].data.display_name = name_gets[i][1];
+            }
+        });
+    },
+    /**
+     * For a given resource of type 'record', fetch all data.
+     *
+     * @param {Object} record local resource
+     * @param {string[]} [fieldNames] the list of fields to fetch. If not given,
+     *   fetch all the fields in record.fieldNames (+ display_name)
+     * @returns {Deferred -> Object} resolves to the record
+     */
+    _fetchRecord: function (record, fieldNames) {
+        var self = this;
+        fieldNames = fieldNames || _.uniq(record.fieldNames.concat(['display_name']));
+        var oldData = record.data;
+        return this.performModelRPC(record.model, 'read', [record.res_id, fieldNames], {
+            // context: { 'bin_size': true }, // FIXME: when editing a subrecord in the partner form view, it tries to write the bin_size on the image field
+        }).then(function (result) {
+            result = result[0];
+            record.data = _.extend({}, record.data, result);
+            return self._postprocess(record);
+        }).then(function (record) {
+            // process many2one: split [id, nameget] and create corresponding record
+            _.each(fieldNames, function (name) {
+                var field = record.fields[name];
+                var val = record.data[name];
+                if (field.type === 'many2one') {
+                    if (val !== false) {
+                        // the many2one value is of the form [id, display_name]
+                        var r = self._makeDataPoint({
+                            modelName: field.relation,
+                            data: {
+                                display_name: val[1],
+                                id: val[0],
+                            },
+                        });
+                        record.data[name] = r.id;
+                    } else {
+                        // no value for the many2one
+                        record.data[name] = false;
+                    }
+                }
+            });
+        }).then(function () {
+            return self._fetchX2Manys(record, oldData, fieldNames).then(function () {
+                return record;
+            });
+        });
+    },
+    /**
+     * This method is incorrectly named.  It should be named something like
+     * _fetchMany2OneData.
+     *
+     * For a given record, this method fetches all many2ones information,
+     * batching the requests if possible (for example, if 3 many2ones are in
+     * relation on the same model, then we can probably fetch them in one rpc)
+     *
+     * This method is currently only called by makeDefaultRecord, it should be
+     * called by the onchange methods at some point.
+     *
+     * @todo fix bug: returns a list of deferred, not a deferred
+     *
+     * @param {Object} record a valid resource object
+     * @returns {Deferred}
+     */
+    _fetchRelationalData: function (record) {
+        var self = this;
+        var toBeFetched = [];
+
+        // find all many2one related records to be fetched
+        _.each(record.fieldNames, function (name) {
+            var field = record.fields[name];
+            if (field.type === 'many2one') {
+                var localId = (record._changes && record._changes[name]) || record.data[name];
+                var relatedRecord = self.localData[localId];
+                if (!relatedRecord) {
+                    return;
+                }
+                toBeFetched.push(relatedRecord);
+            }
+        });
+
+        // group them by model and context. Using the context as key is
+        // necessary to make sure the correct context is used for the rpc;
+        var groups = _.groupBy(toBeFetched, function (rec) {
+            return [rec.model, JSON.stringify(rec.context)].join();
+        });
+
+        return $.when.apply($, _.map(groups, this._fetchMany2OneGroup.bind(this)));
+    },
+    /**
+     * Fetch all data in a ungrouped list
+     *
+     * @param {Object} list a valid resource object
+     * @returns {Deferred -> Object} resolves to the fecthed list
+     */
+    _fetchUngroupedList: function (list) {
+        var self = this;
+        var def;
+        if (list.static) {
+            def = this._readUngroupedList(list);
+        } else {
+            def = this._searchReadUngroupedList(list);
+        }
+        return def.then(function () {
+            return self._fetchX2ManysBatched(list);
+        }).then(function () {
+            return list;
+        });
+    },
+    /**
+     * X2Manys have to be fetched by separate rpcs (their data are stored on
+     * different models). This method takes a record, look at its x2many fields,
+     * then, if necessary, create a local resource and fetch the corresponding
+     * data.
+     *
+     * It also tries to reuse data, if it can find an existing list, to prevent
+     * useless rpcs.
+     *
+     * @param {Object} record local resource
+     * @param {Object} oldData the data fetched previously
+     * @param {string[]} [fieldNames] list of fields to fetch
+     * @returns {Deferred}
+     */
+    _fetchX2Manys: function (record, oldData, fieldNames) {
+        var self = this;
+        var defs = [];
+        fieldNames = fieldNames || record.fieldNames;
+        _.each(fieldNames, function (fieldName) {
+            var field = record.fields[fieldName];
+            if (field.type === 'one2many' || field.type === 'many2many') {
+                var list;
+
+                // a previously loaded list exists
+                if (oldData[fieldName]) {
+                    list = self.localData[oldData[fieldName]];
+                    list.res_ids = record.data[fieldName];
+                    list.count = list.res_ids.length;
+                    list.offset = list.offset < list.count ? list.offset : 0;
+                } else {
+                    // need to create a list from scratch
+                    var attrs = record.fieldAttrs[fieldName];
+                    var rawContext = attrs && attrs.context;
+                    var ids = record.data[fieldName] || [];
+                    list = self._makeDataPoint({
+                        count: ids.length,
+                        fieldAttrs: field.fieldAttrs,
+                        fields: field.relatedFields,
+                        limit: field.limit,
+                        modelName: field.relation,
+                        res_ids: ids,
+                        static: true,
+                        type: 'list',
+                        parentID: record.id,
+                        rawContext: rawContext,
+                    });
+                }
+                record.data[fieldName] = list.id;
+                if (!field.__no_fetch) {
+                    defs.push(self._readUngroupedList(list));
+                }
+            }
+        });
+        return $.when.apply($, defs);
+    },
+    /**
+     * batch requests for 1 x2m in list
+     *
+     * @see _fetchX2ManysBatched
+     * @param {Object} list
+     * @param {string} fieldName
+     * @returns {Deferred}
+     */
+    _fetchX2ManyBatched: function (list, fieldName) {
+        var self = this;
+        var field = list.fields[fieldName];
+
+        // step 1: collect ids
+        var ids = [];
+        _.each(list.data, function (dataPoint) {
+            var record = self.localData[dataPoint];
+            ids = _.unique(ids.concat(record.data[fieldName] || []));
+            var m2mList = self._makeDataPoint({
+                fieldAttrs: field.fieldAttrs,
+                fields: field.relatedFields,
+                modelName: field.relation,
+                res_ids: record.data[fieldName],
+                static: true,
+                type: 'list',
+            });
+            record.data[fieldName] = m2mList.id;
+        });
+
+        if (!ids.length || field.__no_fetch) {
+            return $.when();
+        }
+
+        // step 2: fetch data from server
+        return this.performModelRPC(field.relation, 'read', [ids, _.keys(field.relatedFields)], {
+            context: {}, // FIXME
+        }).then(function (results) {
+            // step 3: assign values to correct datapoints
+            var dataPoints = _.map(results, function (result) {
+                return self._makeDataPoint({
+                    modelName: field.relation,
+                    data: result,
+                    fields: field.relatedFields,
+                    fieldAttrs: field.fieldAttrs,
+                });
+            });
+
+            _.each(list.data, function (dataPoint) {
+                var record = self.localData[dataPoint];
+                var m2mList = self.localData[record.data[fieldName]];
+
+                m2mList.data = [];
+                _.each(m2mList.res_ids, function (res_id) {
+                    var dataPoint = _.find(dataPoints, function (d) {
+                        return d.res_id === res_id;
+                    });
+                    m2mList.data.push(dataPoint.id);
+                    m2mList.count++;
+                });
+            });
+        });
+    },
+    /**
+     * batch request for x2ms for datapoint of type list
+     *
+     * @param {Object} list
+     * @returns {Deferred}
+     */
+    _fetchX2ManysBatched: function (list) {
+        var defs = [];
+        for (var i = 0; i < list.fieldNames.length; i++) {
+            var field = list.fields[list.fieldNames[i]];
+            if (field.type === 'many2many' || field.type === 'one2many') {
+                defs.push(this._fetchX2ManyBatched(list, list.fieldNames[i]));
+            }
+        }
+        return $.when.apply($, defs);
+    },
+    /**
+     * Read all x2many fields and generate the commands for the server to create
+     * or write them...
+     *
+     * @param {Object} record
+     * @returns {Object} a map from some field names to commands
+     */
+    _generateX2ManyCommands: function (record) {
+        var self = this;
+        var commands = {};
+        var type, list, relData, relIds, removedIds, addedIds, keptIds, relRecord, i;
+
+        var data = _.extend({}, record.data, record._changes);
+
+        for (var fieldName in record.fields) {
+            type = record.fields[fieldName].type;
+
+            if (type === 'many2many' || type === 'one2many') {
+                // skip if this field is empty
+                if (!data[fieldName]) {
+                    commands[fieldName] = null;
+                    continue;
+                }
+                list = this.localData[data[fieldName]];
+                if (!list._changes) {
+                    commands[fieldName] = null;
+                    // skip if this field hasn't changed
+                    continue;
+                }
+                relData = _.map(list._changes, function (localId) {
+                    return self.localData[localId];
+                });
+                relIds = _.pluck(relData, 'res_id');
+                commands[fieldName] = [];
+
+                if (type === 'many2many') {
+                    // deliberately generate a single 'replace' command instead
+                    // of a 'delete' and a 'link' commands with the exact diff
+                    // because 1) performance-wise it doesn't change anything
+                    // and 2) to guard against concurrent updates (policy: force
+                    // an complete override of the actual value of the m2m)
+                    commands[fieldName].push(x2ManyCommands.replace_with(relIds));
+                } else if (type === 'one2many') {
+                    removedIds = _.difference(list.res_ids, relIds);
+                    addedIds = _.difference(relIds, list.res_ids);
+                    keptIds = _.intersection(list.res_ids, relIds);
+                    for (i = 0; i < keptIds.length; i++) {
+                        commands[fieldName].push(x2ManyCommands.link_to(keptIds[i]));
+                    }
+                    for (i = 0; i < removedIds.length; i++) {
+                        commands[fieldName].push(x2ManyCommands.delete(removedIds[i]));
+                    }
+                    for (i = 0; i < addedIds.length; i++) {
+                        relRecord = _.findWhere(relData, {res_id: addedIds[i]});
+                        relRecord = this.get(relRecord.id, {raw: true});
+                        commands[fieldName].push(x2ManyCommands.create(_.omit(relRecord.data, 'id')));
+                    }
+                    // FIXME: update of records temporarily disabled as it doesn't work if we updated
+                    // the record in a form view, as the _changes contains all the fields of the
+                    // form view instead of the one that have changed
+                    // _.each(relData, function (relRecord) {
+                    //     var new_values = relRecord._changes;
+                    //     if (!_.isEmpty(new_values)) {
+                    //         commands[fieldName].push(x2ManyCommands.update(relRecord.res_id, new_values));
+                    //     }
+                    // });
+                }
+            }
+        }
+
+        return commands;
+    },
+    /**
+     * Every RPC done by the model need to add some context, which is a
+     * combination of the context of the session, of the record/list, and/or of
+     * the concerned field. This method combines all these contexts and evaluate
+     * them with the proper evalcontext.
+     *
+     * @param {Object} element an element from the localData
+     * @param {Object} [options]
+     * @param {string} [options.field] if given, the context of the field will
+     *   also be added (and evaluated) to the result
+     * @returns {Object} the evaluated context
+     */
+    _getContext: function (element, options) {
+        var context = new data.CompoundContext(session.user_context, element.context);
+        if (options && options.field) {
+            var attrs = element.fieldAttrs[options.field];
+            if (attrs && attrs.context) {
+                context.add(attrs.context);
+            }
+        }
+        if (element.rawContext) {
+            context.add(element.rawContext);
+            var evalContext = this.get(element.parentID, {raw: true}).data;
+            context.set_eval_context(evalContext);
+        }
+        return context.eval();
+    },
+    /**
+     * Helper method for the load entry point.
+     *
+     * @see load
+     *
+     * @param {Object} dataPoint some local resource
+     * @param {Object} [options]
+     * @param {string[]} [options.fieldNames] the fields to fetch for a record
+     * @returns {Deferred}
+     */
+    _load: function (dataPoint, options) {
+        if (dataPoint.type === 'record') {
+            return this._fetchRecord(dataPoint, options && options.fieldNames);
+        }
+        if (dataPoint.type === 'list' && dataPoint.groupedBy.length) {
+            return this._readGroup(dataPoint);
+        }
+        if (dataPoint.type === 'list' && !dataPoint.groupedBy.length) {
+            return this._fetchUngroupedList(dataPoint);
+        }
+    },
+    /**
+     * Turns a bag of properties into a valid local resource.  Also, register
+     * the resource in the localData object.
+     *
+     * @param {Object} params
+     * @param {Object} [params.fieldAttrs={}] contains the attrs of each field
+     * @param {Array} [params.fieldNames] the name of fields to load, the list
+     *   of all fields by default
+     * @param {Object} params.fields contains the description of each field
+     * @returns {Object} the resource created
+     */
+    _makeDataPoint: function (params) {
+        var type = params.type || ('domain' in params && 'list') || 'record';
+
+        var res_id;
+        var value;
+        if (type === 'record') {
+            res_id = params.res_id || (params.data && params.data.id) || _.uniqueId('virtual_');
+        } else {
+            var value_is_array = params.value instanceof Array;
+            res_id = value_is_array ? params.value[0] : undefined;
+            value = value_is_array ? params.value[1] : params.value;
+        }
+        params.res_id = res_id;
+
+        var dataPoint = {
+            context: params.context || {},
+            domain: params.domain || [],
+            groupedBy: params.groupedBy || [],
+            id: _.uniqueId(params.modelName + '_'),
+            model: params.modelName,
+            res_id: res_id,
+            res_ids: params.res_ids || [],
+        };
+
+        this.localData[dataPoint.id] = dataPoint;
+
+        var fields = _.extend({
+            display_name: {type: 'char'},
+            id: {type: 'integer'},
+        }, params.fields);
+
+        _.extend(dataPoint, {
+            _cache: type === 'list' ? {} : undefined,
+            _changes: null,
+            aggregateValues: params.aggregateValues || {},
+            count: params.count || dataPoint.res_ids.length,
+            data: params.data || (type === 'record' ? {} : []),
+            fieldNames: params.fieldNames || Object.keys(fields),
+            fields: fields,
+            fieldAttrs: params.fieldAttrs || {},
+            isOpen: params.isOpen,
+            limit: type === 'record' ? 1 : params.limit,
+            offset: params.offset || (type === 'record' ? _.indexOf(dataPoint.res_ids, res_id) : 0),
+            openGroupByDefault: params.openGroupByDefault,
+            orderedBy: params.orderedBy || [],
+            parentID: params.parentID,
+            rawContext: params.rawContext,
+            static: params.static || false,
+            type: type,  // 'record' | 'list'
+            value: value,
+        });
+
+        return dataPoint;
+    },
+    /**
+     * Once a record is created and some data has been fetched, we need to do
+     * quite a lot of computations to determine what needs to be fetched. This
+     * method is doing that.
+     *
+     * @see _fetchRecord @see makeDefaultRecord
+     *
+     * @param {any} record
+     * @returns {Deferred -> Object} resolves to the finished resource
+     */
+    _postprocess: function (record) {
+        var self = this;
+        var defs = [];
+        _.each(record.fieldNames, function (name) {
+            var field = record.fields[name];
+            var attrs = record.fieldAttrs[name];
+            if (field.__fetch_status && !field.__status_information) {
+                var field_values = _.mapObject(record.data, function (val, key) {
+                    var fieldType = record.fields[key].type;
+                    if (fieldType === 'many2one') {
+                        return val instanceof Array && val[0];
+                    }
+                    return val;
+                });
+                var _domain = new data.CompoundDomain(field.domain || {}).set_eval_context(field_values);
+                var domain = pyeval.eval('domain', _domain);
+                var fold_field = pyeval.py_eval(attrs.options || '{}').fold_field;
+                var fetch_status_information = self.performRPC('/web/dataset/search_read', {
+                    model: field.relation,
+                    fields: ['id'].concat(fold_field ? [fold_field] : []),
+                    domain: domain,
+                }).then(function (result) {
+                    var ids = _.pluck(result.records, 'id');
+                    return self.performModelRPC(field.relation, 'name_get', [ids], {
+                        context: self._getContext(record, {field: name}),
+                    }).then(function (name_gets) {
+                        _.each(result.records, function (record) {
+                            var name_get = _.find(name_gets, function (n) {
+                                return n[0] === record.id;
+                            });
+                            record.display_name = name_get[1];
+                        });
+                        field.__status_information = result.records;
+                    });
+                });
+                defs.push(fetch_status_information);
+            }
+            if (field.__always_reload) {
+                if (record.data[name] instanceof Array) {
+                    defs.push(self.performModelRPC(field.relation, 'name_get', [record.data[name][0]], {
+                        context: self._getContext(record, {field: name}),
+                    }).then(function (result) {
+                        record.data[name] = result[0];
+                    }));
+                }
+            }
+            if (field.__fetch_selection && !self.many2ones[field.relation]) {
+                var fetchSelection = self
+                    .performModelRPC(field.relation, 'name_search', [], {})
+                    .then(function (result) {
+                        self.many2ones[field.relation] = result;
+                    });
+                defs.push(fetchSelection);
+            }
+            if (field.__fetch_many2manys) {
+                var fetchMany2Manys = self
+                    .performModelRPC(field.relation, 'name_search', [], {})
+                    .then(function (result) {
+                        self.many2manys[field.relation] = result;
+                    });
+                defs.push(fetchMany2Manys);
+            }
+        });
+
+        return $.when.apply($, defs).then(function () {
+            return record;
+        });
+    },
+    /**
+     * For a grouped list resource, this method fetches all group data by
+     * performing a /read_group. It also tries to read open subgroups if they
+     * were open before.
+     *
+     * @param {Object} list valid resource object
+     * @returns {Deferred<Object>} resolves to the fetched group object
+     */
+    _readGroup: function (list) {
+        var self = this;
+        var fields = _.uniq(list.fieldNames.concat(list.groupedBy));
+        return this.performModelRPC(list.model, 'read_group', [], {
+            fields: fields,
+            context: list.context,
+            groupby: list.groupedBy,
+            domain: list.domain,
+            orderby: false,
+            lazy: true,
+        }).then(function (groups) {
+            var rawGroupBy = list.groupedBy[0].split(':')[0];
+            var previousGroups = _.map(list.data, function (groupID) {
+                return self.localData[groupID];
+            });
+            list.data = [];
+            list.count = groups.length;
+            var defs = [];
+
+            _.each(groups, function (group) {
+                var aggregateValues = {};
+                _.each(group, function (value, key) {
+                    if (_.contains(fields, key) && key !== list.groupedBy[0]) {
+                        aggregateValues[key] = value;
+                    }
+                });
+                var newGroup = self._makeDataPoint({
+                    modelName: list.model,
+                    count: group[rawGroupBy + '_count'],
+                    domain: group.__domain,
+                    context: list.context,
+                    fields: list.fields,
+                    fieldNames: list.fieldNames,
+                    fieldAttrs: list.fieldAttrs,
+                    value: group[rawGroupBy],
+                    aggregateValues: aggregateValues,
+                    groupedBy: list.groupedBy.slice(1),
+                    orderedBy: list.orderedBy,
+                    limit: list.limit,
+                    openGroupByDefault: list.openGroupByDefault,
+                    type: 'list', // nested groupedBys not handled yet
+                });
+                list.data.push(newGroup.id);
+                var old_group = _.find(previousGroups, function (g) {
+                    return g.res_id === newGroup.res_id && g.value === newGroup.value;
+                });
+                if (old_group) {
+                    newGroup.isOpen = old_group.isOpen;
+                } else if (!newGroup.openGroupByDefault) {
+                    newGroup.isOpen = false;
+                } else {
+                    newGroup.isOpen = '__fold' in group ? !group.__fold : true;
+                }
+                if (newGroup.isOpen && newGroup.count > 0) {
+                    defs.push(self._fetchUngroupedList(newGroup));
+                }
+            });
+            return $.when.apply($, defs).then(function () {
+                // generate the res_ids of the main list, being the concatenation
+                // of the fetched res_ids in each group
+                list.res_ids = _.flatten(_.map(arguments, function (group) {
+                    return group ? group.res_ids : [];
+                }));
+                return list;
+            });
+        });
+    },
+    /**
+     * For 'static' list, such as one2manys in a form view, we can do a /read
+     * instead of a /search_read.
+     *
+     * @param {Object} list a valid resource object
+     * @returns {Deferred -> Object} resolves to the fetched list object
+     */
+    _readUngroupedList: function (list) {
+        var self = this;
+        var def;
+        var ids = [];
+        var missingIds = [];
+        var upper_bound = list.limit ? Math.min(list.offset + list.limit, list.count) : list.count;
+        for (var i = list.offset; i < upper_bound; i++) {
+            var id = list.res_ids[i];
+            ids.push(id);
+            if (!list._cache[id]) {
+                missingIds.push(id);
+            }
+        }
+        if (missingIds.length) {
+            def = this.performModelRPC(list.model, 'read', [missingIds, list.fieldNames], {
+                context: {}, // FIXME
+            });
+        } else {
+            def = $.when();
+        }
+        return def.then(function (records) {
+            list.data = [];
+            _.each(ids, function (id) {
+                var dataPoint;
+                if (id in list._cache) {
+                    dataPoint = self.localData[list._cache[id]];
+                } else {
+                    dataPoint = self._makeDataPoint({
+                        modelName: list.model,
+                        data: _.findWhere(records, {id: id}),
+                        fields: list.fields,
+                        fieldNames: list.fieldNames,
+                        fieldAttrs: list.fieldAttrs,
+                    });
+
+                    // add many2one records
+                    _.each(dataPoint.fieldNames, function (name) {
+                        var field = dataPoint.fields[name];
+                        if (field.type === 'many2one') {
+                            var r = self._makeDataPoint({
+                                modelName: field.relation,
+                                data: {
+                                    id: dataPoint.data[name][0],
+                                    display_name: dataPoint.data[name][1],
+                                }
+                            });
+
+                            dataPoint.data[name] = r.id;
+                        }
+                    });
+                    list._cache[id] = dataPoint.id;
+                }
+                list.data.push(dataPoint.id);
+            });
+            self._sortList(list);
+            return list;
+        });
+    },
+    /**
+     * Do a /search_read to get data for a list resource.  This does a
+     * /search_read because the data may not be static (for ex, a list view).
+     *
+     * @param {Object} list
+     * @returns {Deferred}
+     */
+    _searchReadUngroupedList: function (list) {
+        var self = this;
+        return this.performRPC('/web/dataset/search_read', {
+            model: list.model,
+            fields: list.fieldNames,
+            domain: list.domain || [],
+            offset: list.offset,
+            limit: list.limit,
+            sort: this._serializeSort(list.orderedBy),
+        }).then(function (result) {
+            list.count = result.length;
+            var data = _.map(result.records, function (record) {
+                var dataPoint = self._makeDataPoint({
+                    data: record,
+                    fields: list.fields,
+                    fieldNames: list.fieldNames,
+                    fieldAttrs: list.fieldAttrs,
+                    modelName: list.model,
+                });
+
+                // add many2one records
+                _.each(dataPoint.fieldNames, function (name) {
+                    var field = dataPoint.fields[name];
+                    if (field.type === 'many2one') {
+                        var r = self._makeDataPoint({
+                            modelName: field.relation,
+                            data: {
+                                id: dataPoint.data[name][0],
+                                display_name: dataPoint.data[name][1],
+                            }
+                        });
+
+                        dataPoint.data[name] = r.id;
+                    }
+                });
+                return dataPoint.id;
+            });
+            list.data = data;
+            list.res_ids = _.pluck(result.records, 'id');
+            return list;
+        });
+    },
+    /**
+     * Helper method, generates a string to describe a ordered by sequence for
+     * SQL.
+     *
+     * For example, [{name: 'foo', asc: true}, {name: 'bar', asc: false}] will
+     * be converted into 'foo ASC, bar DESC'
+     *
+     * @param {Object[]} orderBy list of objects {name:..., asc: ...}
+     * @returns {string}
+     */
+    _serializeSort: function (orderBy) {
+        return _.map(orderBy, function (order) {
+            return order.asc ? order.name + ' ASC' : order.name + ' DESC';
+        }).join(', ');
+    },
+    /**
+     * Change the offset of a record. Note that this does not reload the data.
+     * The offset is used to load a different record in a list of record (for
+     * example, a form view with a pager.  Clicking on next/previous actually
+     * changes the offset through this method).
+     *
+     * @param {string} elementId local id for the resource
+     * @param {number} offset
+     */
+    _setOffset: function (elementId, offset) {
+        var element = this.localData[elementId];
+        element.offset = offset;
+        if (element.type === 'record' && element.res_ids.length) {
+            element.res_id = element.res_ids[offset];
+        }
+    },
+    /**
+     * Do a in-memory sort of a list resource data points. This method assumes
+     * that the list data has already been fetched.  Its intended use is for
+     * static datasets, such as a one2many in a form view.
+     *
+     * @param {Object} list
+     */
+    _sortList: function (list) {
+        var self = this;
+        if (list.orderedBy.length) {
+            // sort records according to ordered_by[0]
+            var order = list.orderedBy[0];
+            list.data.sort(function (r1, r2) {
+                var data1 = self.localData[r1].data;
+                var data2 = self.localData[r2].data;
+                if (data1[order.name] < data2[order.name]) {
+                    return order.asc ? -1 : 1;
+                }
+                if (data1[order.name] > data2[order.name]) {
+                    return order.asc ? 1 : -1;
+                }
+                return 0;
+            });
+        }
+    },
+    /**
+     * Helper method.  Recursively traverses the data, starting from the element
+     * record (or list), then following all relations.  This is useful when one
+     * want to determine a property for the current record.
+     *
+     * For example, isDirty need to check all relations to find out if something
+     * has been modified, or not.
+     *
+     * @param {Object} element a valid local resource
+     * @param {callback} fn a function to be called on each visited element
+     */
+    _visitChildren: function (element, fn) {
+        var self = this;
+        fn(element);
+        if (element.type === 'record') {
+            for (var fieldName in element.data) {
+                var field = element.fields[fieldName];
+                if (_.contains(['one2many', 'many2one', 'many2many'], field.type)) {
+                    var relationalElement = this.localData[element.data[fieldName]];
+
+                    // relationalElement could be empty in the case of a many2one
+                    if (relationalElement) {
+                        self._visitChildren(relationalElement, fn);
+                    }
+                }
+            }
+        }
+        if (element.type === 'list') {
+            _.each(element.data, function (elemId) {
+                var elem = self.localData[elemId];
+                self._visitChildren(elem, fn);
+            });
+        }
+    },
+});
+
+return Model;
+
+});
+