bug 1260197 - handle spam and midair collision error messages

kuma/static/js/wiki-edit.js

@@ -496,7 +496,6 @@
             var formURL = window.location.href; // submits to self
             console.log('posting this data: ', formData)
 
-            // ajax submit
             $.ajax({
                 url : formURL + '?async',
                 type: "POST",
@@ -528,16 +527,22 @@
                         // We also need to update the form's current_rev to
                         // avoid triggering a conflict, since we just saved in
                         // the background.
-                        var responseRevision = JSON.parse(data)['new_revision_id'];
-                        console.log('responseRevision: ', responseRevision);
-                        // TODO: why are there multiple <input id="id_current_rev">s?
-                        $("input[id=id_current_rev]").val(responseRevision)
-
-                        // Clear the review comment
-                        $('#id_comment').val('');
-
-                        // Trigger a `mdn:save-success` event so dirtiness can be reset throughout the page
-                        $form.trigger('mdn:save-success');
+                        console.log('data is: ', data)
+                        var responseData = JSON.parse(data)
+                        if (responseData['error'] == true) {
+                            saveNotification.error(responseData['error_message'])
+                        } else {
+                            var responseRevision = JSON.parse(data)['new_revision_id'];
+                            console.log('responseRevision: ', responseRevision);
+                            // TODO: why are there multiple <input id="id_current_rev">s?
+                            $("input[id=id_current_rev]").val(responseRevision)
+
+                            // Clear the review comment
+                            $('#id_comment').val('');
+
+                            // Trigger a `mdn:save-success` event so dirtiness can be reset throughout the page
+                            $form.trigger('mdn:save-success');
+                        }
 
                         // Re-enable the form; it gets disabled to prevent double-POSTs
                         $form.data('disabled', false).removeClass('disabled');
@@ -549,9 +554,13 @@
                     // console.log(jqXHR.status);
                     // console.log(textStatus);
                     // console.log(errorThrown);
-                    var msg = "Publishing failed. Please copy and paste your changes into a safe place and try submitting the form using the 'Publish' button.";
-
-                    saveNotification.error(msg);
+                    // Try to display the error that comes back from the server
+                    try {
+                        var errorMessage = JSON.parse(jqXHR['responseText'])['error_message']
+                    } catch (err) {
+                        errorMessage = "Publishing failed. Please copy and paste your changes into a safe place and try submitting the form using the 'Publish' button.";
+                    }
+                    saveNotification.error(errorMessage);
 //                    saveNotification.error(msg, {closable: true, duration: 0});
 
                     // save draft

kuma/wiki/forms.py

@@ -17,6 +17,7 @@
 
 import kuma.wiki.content
 from kuma.core.form_fields import StrippedCharField
+from kuma.core.urlresolvers import reverse
 from kuma.spam.akismet import AkismetError
 from kuma.spam.forms import AkismetCheckFormMixin, AkismetSubmissionFormMixin
 
@@ -64,8 +65,10 @@
 SLUG_COLLIDES = _(u'Another document with this slug already exists.')
 OTHER_COLLIDES = _(u'Another document with this metadata already exists.')
 
-MIDAIR_COLLISION = _(u'This document was modified while you were '
-                     u'editing it.')
+MIDAIR_COLLISION = _(u'Publishing failed. Conflicting edit attempts detected. '
+                     u'Please copy and paste your edits to a safe place and '
+                     u'visit the <a href="%(url)s">revision history</a> page '
+                     u'to see what was changed before making further edits.')
 MOVE_REQUIRED = _(u"Changing this document's slug requires "
                   u"moving it and its children.")
 
@@ -659,13 +662,21 @@ def clean_current_rev(self):
                     if orig_ct != curr_ct:
                         # Oops. Looks like the section did actually get
                         # changed, so yeah this is a collision.
-                        raise forms.ValidationError(MIDAIR_COLLISION)
+                        url = reverse(
+                            'wiki.document_revisions',
+                            kwargs={'document_path': self.instance.document.slug}
+                        )
+                        raise forms.ValidationError(MIDAIR_COLLISION % {'url': url})
 
                     return current_rev
 
                 else:
                     # No section edit, so this is a flat-out collision.
-                    raise forms.ValidationError(MIDAIR_COLLISION)
+                    url = reverse(
+                        'wiki.document_revisions',
+                        kwargs={'document_path': self.instance.document.slug}
+                    )
+                    raise forms.ValidationError(MIDAIR_COLLISION % {'url': url})
 
         except Document.DoesNotExist:
             # If there's no document yet, just bail.

kuma/wiki/views/edit.py

@@ -208,6 +208,14 @@ def edit(request, document_slug, document_locale, revision_id=None):
                 if not rev_form.is_valid():
                     # Was there a mid-air collision?
                     if 'current_rev' in rev_form._errors:
+                        # If this was an Ajax POST, then return a JSONReponse
+                        if is_async_submit:
+                            data = {
+                                "error": True,
+                                "error_message": rev_form.errors['current_rev'],
+                                "new_revision_id": curr_rev.id,
+                            }
+                            return JsonResponse(data=data, status=500)
                         # Jump out to a function to escape indentation hell
                         return _edit_document_collision(
                             request, orig_rev, curr_rev, is_async_submit,