[ADD] tentative removal of attachments

Attachments ought be removed only if they are not used in an existing page/web
view.

Theoretically this could be set directly in unlink(), but:
* that would make a nice error message significantly harder
* the expenses of performing a text search in all view archs would be a bit expensive

Notes:
* the views set could be reduced to only "web" views
* the search is likely sensible to false negatives e.g. different order of
  query parameters. It *will* remove images still being used.

bzr revid: xmo@openerp.com-20140304110716-u14w6uo8fbkfa42i

addons/website/models/website.py

@@ -9,6 +9,7 @@ import urlparse
 
 import werkzeug
 import werkzeug.exceptions
+import werkzeug.utils
 import werkzeug.wrappers
 # optional python-slugify import (https://github.com/un33k/python-slugify)
 try:
@@ -594,6 +595,33 @@ class ir_attachment(osv.osv):
         return super(ir_attachment, self).create(
             cr, uid, values, context=context)
 
+    def try_remove(self, cr, uid, ids, context=None):
+        """ Removes a web-based image attachment if it is used by no view
+        (template)
+
+        Returns a dict mapping attachments which would not be removed (if any)
+        mapped to the views preventing their removal
+        """
+        Views = self.pool['ir.ui.view']
+        attachments_to_remove = []
+        # views blocking removal of the attachment
+        removal_blocked_by = {}
+
+        for attachment in self.browse(cr, uid, ids, context=context):
+            # in-document URLs are html-escaped, a straight search will not
+            # find them
+            url = werkzeug.utils.escape(attachment.website_url)
+            ids = Views.search(cr, uid, [('arch', 'like', url)], context=context)
+
+            if ids:
+                removal_blocked_by[attachment.id] = Views.read(
+                    cr, uid, ids, ['name'], context=context)
+            else:
+                attachments_to_remove.append(attachment.id)
+        if attachments_to_remove:
+            self.unlink(cr, uid, attachments_to_remove, context=context)
+        return removal_blocked_by
+
 class res_partner(osv.osv):
     _inherit = "res.partner"
 

addons/website/static/src/css/editor.css

@@ -251,6 +251,26 @@ ul.oe_menu_editor .disclose {
 .existing-attachments .pager .disabled {
   display: none;
 }
+.existing-attachments .existing-attachment-cell {
+  position: relative;
+}
+.existing-attachments .existing-attachment-cell .img {
+  border: 1px solid #848490;
+}
+.existing-attachments .existing-attachment-cell .existing-attachment-remove {
+  position: absolute;
+  top: 0;
+  left: 15px;
+  cursor: pointer;
+  background: white;
+  padding: 2px;
+  border: 1px solid #848490;
+  border-top: none;
+  border-left: none;
+  -moz-border-radius-bottomright: 8px;
+  -webkit-border-bottom-right-radius: 8px;
+  border-bottom-right-radius: 8px;
+}
 
 .cke_widget_wrapper {
   position: static !important;

addons/website/static/src/css/editor.sass

@@ -211,9 +211,27 @@ ul.oe_menu_editor
         .font-icons-selected
             background-color: #ddd
 
+$attachment-border-color: #848490
+.existing-attachments
+    .pager .disabled
+        display: none
 
-.existing-attachments .pager .disabled
-    display: none
+    .existing-attachment-cell
+        position: relative
+        .img
+            border: 1px solid $attachment-border-color
+        .existing-attachment-remove
+            position: absolute
+            top: 0
+            left: 15px // padding-left on col-*
+
+            cursor: pointer
+            background: white
+            padding: 2px
+            border: 1px solid $attachment-border-color
+            border-top: none
+            border-left: none
+            +border-bottom-right-radius(8px)
 
 // wrapper positioned relatively for drag&drop widget which is disabled below.
 // Breaks completely horribly crazy products listing page, so take it out.

addons/website/static/src/js/website.editor.js

@@ -1441,6 +1441,7 @@
                 this.page += $target.hasClass('previous') ? -1 : 1;
                 this.display_attachments();
             },
+            'click .existing-attachment-remove': 'try_remove',
         }),
         init: function (parent) {
             this.image = null;
@@ -1473,6 +1474,7 @@
             this.display_attachments();
         },
         display_attachments: function () {
+            this.$('.help-block').empty();
             var per_screen = IMAGES_PER_ROW * IMAGES_ROWS;
 
             var from = this.page * per_screen;
@@ -1500,6 +1502,34 @@
             }
             this.close()
         },
+
+        try_remove: function (e) {
+            var $help_block = this.$('.help-block').empty();
+            var self = this;
+            var id = parseInt($(e.target).data('id'), 10);
+            var attachment = _.findWhere(this.records, {id: id});
+
+            return openerp.jsonRpc('/web/dataset/call_kw', 'call', {
+                model: 'ir.attachment',
+                method: 'try_remove',
+                args: [],
+                kwargs: {
+                    ids: [id],
+                    context: website.get_context()
+                }
+            }).then(function (prevented) {
+                if (_.isEmpty(prevented)) {
+                    self.records = _.without(self.records, attachment);
+                    self.display_attachments();
+                    return;
+                }
+                $help_block.replaceWith(openerp.qweb.render(
+                    'website.editor.dialog.image.existing.error', {
+                        views: prevented[id]
+                    }
+                ));
+            });
+        },
     });
 
     function get_selected_link(editor) {

addons/website/static/src/xml/website.editor.xml

@@ -140,8 +140,9 @@
                         <button type="button" class="close" data-dismiss="modal" aria-hidden="true">×</button>
                         <h3 class="modal-title">Select a Picture</h3>
                     </div>
-                    <div class="modal-body">
+                    <div class="modal-body has-error">
                         <div class="existing-attachments"/>
+                        <div class="help-block"/>
                     </div>
                     <div class="modal-footer">
                         <a href="#" data-dismiss="modal" aria-hidden="true">Discard</a>
@@ -157,12 +158,27 @@
                 <li class="next disabled"><a href="#">Next →</a></li>
             </ul>
             <div class="row mt16" t-foreach="rows" t-as="row">
-                <div class="col-sm-2" t-foreach="row" t-as="attachment">
+                <div class="col-sm-2 existing-attachment-cell"
+                     t-foreach="row" t-as="attachment">
+                    <i class="fa fa-times existing-attachment-remove" t-att-data-id="attachment.id"/>
                     <img t-att-src="attachment.website_url" t-att-alt="attachment.name" class="img img-responsive"/>
                 </div>
             </div>
         </div>
     </t>
+    <t t-name="website.editor.dialog.image.existing.error">
+        <div class="help-block">
+            <p>The image could not be deleted because it is used in the
+               following pages or views:</p>
+            <ul t-foreach="views" t-as="view">
+                <li>
+                    <a t-attf-href="/web#model=ir.ui.view&amp;id=#{view.id}">
+                        <t t-esc="view.name"/>
+                    </a> (id <t t-esc="view.id"/>)
+                </li>
+            </ul>
+        </div>
+    </t>
     <t t-name="website.editor.table.panel">
         <table class="editorbar-panel">
             <tr t-foreach="rows"><td t-foreach="cols">&#8203;</td></tr>