[IMP] significantly improve handling of trying to create a new page which already exists

# Through the menu

Rather than output a generic error (500 due to an IntegrityError),
return a templated 409 letting the user either visit the
page-which-already-exists-with-the-name-he'd-picked or open the page
creation dialog again for a second round.

An alternative would be to promote the website.prompt use to
full-blown dialog as a result of selecting "New Page" and handle the
"page already exists" case without even closing the dialog.

# Through the link dialog

Added an RPC call to check if a page already exists (essentially a
cheaper version of opening /page/whatever and checking whether it's a
200 over JSON-RPC), if the page matching the completion term already
exists, do *not* add the choice of creating the page, only provide
completions from existing pages.

bzr revid: xmo@openerp.com-20131126160148-wrk4zvz9istscwa0

5 files changed, 103 insertions, 27 deletions

diff --git a/addons/website/controllers/main.py b/addons/website/controllers/main.py
index c5628765ed8..a214e6cd334 100644
--- a/addons/website/controllers/main.py
+++ b/addons/website/controllers/main.py
@@ -53,7 +53,12 @@ class Website(openerp.addons.web.controllers.main.Home):
             path = web.new_page(request.cr, request.uid, path, context=request.context)
         except psycopg2.IntegrityError:
             logger.exception('Unable to create ir_model_data for page %s', path)
-            return werkzeug.exceptions.InternalServerError()
+            response = request.website.render('website.creation_failed', {
+                    'page': path,
+                    'path': '/page/' + request.website.page_for_name(name=path)
+                })
+            response.status_code = 409
+            return response
         url = "/page/" + path
         if noredirect is not NOPE:
             return werkzeug.wrappers.Response(url, mimetype='text/plain')
diff --git a/addons/website/models/website.py b/addons/website/models/website.py
index 43b0be03831..62844305403 100644
--- a/addons/website/models/website.py
+++ b/addons/website/models/website.py
@@ -143,6 +143,20 @@ class website(osv.osv):
             cr.execute("ROLLBACK TO SAVEPOINT new_page")
             raise
 
+    def page_for_name(self, cr, uid, ids, name, module='website', context=None):
+        # whatever
+        return '%s.%s' % (module, slugify(name, max_length=50))
+
+    def page_exists(self, cr, uid, ids, name, module='website', context=None):
+        page = self.page_for_name(cr, uid, ids, name, module=module, context=context)
+
+        try:
+            return self.get_template(
+                cr, uid, ids, template=page, context=context
+            ).exists()
+        except:
+            return False
+
     def get_public_user(self, cr, uid, context=None):
         if not self.public_user:
             uid = openerp.SUPERUSER_ID
@@ -185,14 +199,14 @@ class website(osv.osv):
         })
 
     def get_template(self, cr, uid, ids, template, context=None):
-        IMD = self.pool.get("ir.model.data")
+        IMD = self.pool["ir.model.data"]
         try:
             module, xmlid = template.split('.', 1)
-            view_ref = IMD.get_object_reference(cr, uid, module, xmlid)
+            model, id = IMD.get_object_reference(cr, uid, module, xmlid)
         except ValueError: # catches both unpack errors and gor errors
             module, xmlid = 'website', template
-            view_ref = IMD.get_object_reference(cr, uid, module, xmlid)
-        return self.pool.get("ir.ui.view").browse(cr, uid, view_ref[1])
+            model, id = IMD.get_object_reference(cr, uid, module, xmlid)
+        return self.pool["ir.ui.view"].browse(cr, uid, id, context=context)
 
     def _render(self, cr, uid, ids, template, values=None, context=None):
         user = self.pool.get("res.users")
diff --git a/addons/website/static/src/js/website.editor.js b/addons/website/static/src/js/website.editor.js
index 52b3f19e1ba..c50ad392887 100644
--- a/addons/website/static/src/js/website.editor.js
+++ b/addons/website/static/src/js/website.editor.js
@@ -888,7 +888,8 @@
             this._super(editor);
             this.text = null;
             // Store last-performed request to be able to cancel/abort it.
-            this.req = null;
+            this.page_exists_req = null;
+            this.search_pages_req = null;
         },
         start: function () {
             var self = this;
@@ -896,15 +897,20 @@
                 minimumInputLength: 1,
                 placeholder: _t("New or existing page"),
                 query: function (q) {
-                    self.fetch_pages(q.term).then(function (results) {
+                    $.when(
+                        self.page_exists(q.term),
+                        self.fetch_pages(q.term)
+                    ).then(function (exists, results) {
                         var rs = _.map(results, function (r) {
                             return { id: r.url, text: r.name, };
                         });
-                        rs.push({
-                            create: true,
-                            id: q.term,
-                            text: _.str.sprintf(_t("Create page '%s'"), q.term),
-                        });
+                        if (!exists) {
+                            rs.push({
+                                create: true,
+                                id: q.term,
+                                text: _.str.sprintf(_t("Create page '%s'"), q.term),
+                            });
+                        }
                         q.callback({
                             more: false,
                             results: rs
@@ -983,20 +989,30 @@
                 .siblings().removeClass('active')
                 .addBack().removeClass('has-error');
         },
-        fetch_pages: function (term) {
+        call: function (method, args, kwargs) {
             var self = this;
-            if (this.req) { this.req.abort(); }
-            return this.req = openerp.jsonRpc('/web/dataset/call_kw', 'call', {
+            var req = method + '_req';
+
+            if (this[req]) { this[req].abort(); }
+
+            return this[req] = openerp.jsonRpc('/web/dataset/call_kw', 'call', {
                 model: 'website',
-                method: 'search_pages',
-                args: [null, term],
-                kwargs: {
-                    limit: 9,
-                    context: website.get_context()
-                },
+                method: method,
+                args: args,
+                kwargs: kwargs,
             }).always(function () {
-                // request completed -> unstore it
-                self.req = null;
+                self[req] = null;
+            });
+        },
+        page_exists: function (term) {
+            return this.call('page_exists', [null, term], {
+                context: website.get_context(),
+            });
+        },
+        fetch_pages: function (term) {
+            return this.call('search_pages', [null, term], {
+                limit: 9,
+                context: website.get_context(),
             });
         },
     });
diff --git a/addons/website/static/src/xml/website.xml b/addons/website/static/src/xml/website.xml
index b35dd8a9cfc..d5368ec7b94 100644
--- a/addons/website/static/src/xml/website.xml
+++ b/addons/website/static/src/xml/website.xml
@@ -72,16 +72,21 @@
                         <button title="Close" type="button" class="close" data-dismiss="modal">×</button>
                         <div class="h2"><t t-esc="title"/></div>
                     </div>
-                    <div class="modal-body">
+                    <div class="modal-body" t-if="message or backend_url">
                         <section>
                             <t t-esc="message"/>
                         </section>
-                        <section class="mt32">
-                            You have encountered an error. You can edit in the <a t-att-href="backend_url">backend</a> this data.
+                        <section class="mt32" t-if="backend_url">
+                            <p>The web site has encountered an error.</p>
+                            <p>
+                                It might be possible to edit the relevant items
+                                or fix the issue in <a t-href="#{backend_url}">
+                                the classic OpenERP interface</a>.
+                            </p>
                         </section>
                     </div>
                     <div class="modal-footer">
-                        <button type="button" data-dismiss="modal" href="#" class="close btn btn-default">Close</button>
+                        <button type="button" data-dismiss="modal" class="btn btn-primary">Close</button>
                     </div>
                 </div>
             </div>
diff --git a/addons/website/views/website_templates.xml b/addons/website/views/website_templates.xml
index 375cac64dfb..da9f80375f4 100644
--- a/addons/website/views/website_templates.xml
+++ b/addons/website/views/website_templates.xml
@@ -629,5 +629,41 @@ Sitemap: <t t-esc="url_root"/>sitemap.xml
             </t>
         </template>
 
+        <template id="creation_failed">
+            <t t-call="website.layout">
+                <div id="wrap">
+                    <div class="oe_structure">
+                        <div class="container">
+                            <h1 class="text-center">
+                                The page "<em><t t-esc="page"/></em>"
+                                already exists
+                            </h1>
+                            <h3 class="text-center text-muted">We could not create it.</h3>
+                            <ul>
+                                <li>
+                                    You can <a t-href="#{path}">visit the existing page</a>
+                                </li>
+                                <li>Or you can <a href="#" class="create-new-page">
+                                    create an other page.</a></li>
+                            </ul>
+                        </div>
+                    </div>
+                </div>
+                <script type="application/javascript">
+                    $(document.body).on('click', 'a.create-new-page', function (e) {
+                        e.preventDefault();
+                        openerp.website.prompt({
+                            window_title: "New Page",
+                            input: "Page Title",
+                        }).then(function (val) {
+                            if (val) {
+                                document.location = '/pagenew/' + encodeURI(val);
+                            }
+                        });
+                    });
+                </script>
+            </t>
+        </template>
+
      </data>
 </openerp>