[IMP] web: graph views can now aggregate many2ones

The read_group method was recently modified to allow more flexibility.
With this commit, we add the possibility of aggregating many2one fields.
These fields can be aggregating by counting the number of distinct IDs,
directly in postgres.

Also, note that we had to modify the mock server to implement the
corresponding functionality.

2 files changed, 7 insertions, 2 deletions

diff --git a/addons/web/static/src/js/views/graph/graph_model.js b/addons/web/static/src/js/views/graph/graph_model.js
index 0518e279637..f73a40d6b47 100644
--- a/addons/web/static/src/js/views/graph/graph_model.js
+++ b/addons/web/static/src/js/views/graph/graph_model.js
@@ -125,7 +125,12 @@ return AbstractModel.extend({
             return groupBy.split(':')[0];
         });
         if (this.chart.measure !== '__count__') {
-            fields = fields.concat(this.chart.measure);
+            if (this.fields[this.chart.measure].type === 'many2one') {
+                fields = fields.concat(this.chart.measure + ":count_distinct");
+            }
+            else {
+                fields = fields.concat(this.chart.measure);
+            }
         }
         return this._rpc({
                 model: this.modelName,
diff --git a/addons/web/static/src/js/views/graph/graph_view.js b/addons/web/static/src/js/views/graph/graph_view.js
index feb151b02e7..8cfe2dc0272 100644
--- a/addons/web/static/src/js/views/graph/graph_view.js
+++ b/addons/web/static/src/js/views/graph/graph_view.js
@@ -57,7 +57,7 @@ var GraphView = AbstractView.extend({
         var measures = {__count__: {string: _t("Count"), type: "integer"}};
         _.each(this.fields, function (field, name) {
             if (name !== 'id' && field.store === true) {
-                if (field.type === 'integer' || field.type === 'float' || field.type === 'monetary') {
+                if (field.type === 'integer' || field.type === 'float' || field.type === 'monetary' || field.type === 'many2one') {
                     measures[name] = field;
                 }
             }