Fix some dead links

This commit fixes the download link in the activity feed on the
sidebar and the mention link on card description and comments
(replaced by a popup).

`eslint .` now passes without any error or warning.

Fixes #286

client/components/main/editor.js

@@ -68,7 +68,55 @@ EscapeActions.register('textcomplete',
   () => dropdownMenuIsOpened
 );
 
+// XXX I believe we should compute a HTML rendered field on the server that
+// would handle markdown, emojies and user mentions. We can simply have two
+// fields, one source, and one compiled version (in HTML) and send only the
+// compiled version to most users -- who don't need to edit.
+// In the meantime, all the transformation are done on the client using the
+// Blaze API.
+const at = HTML.CharRef({html: '@', str: '@'});
+Blaze.Template.registerHelper('mentions', new Template('mentions', function() {
+  const view = this;
+  const currentBoard = Boards.findOne(Session.get('currentBoard'));
+  const knowedUsers = _.map(currentBoard.members, (member) => {
+    member.username = Users.findOne(member.userId).username;
+    return member;
+  });
+  const mentionRegex = /\B@(\w*)/gi;
+  let content = Blaze.toHTML(view.templateContentBlock);
+
+  let currentMention, knowedUser, linkClass, linkValue, link;
+  while (Boolean(currentMention = mentionRegex.exec(content))) {
+
+    knowedUser = _.findWhere(knowedUsers, { username: currentMention[1] });
+    if (!knowedUser)
+      continue;
+
+    linkValue = [' ', at, knowedUser.username];
+    linkClass = 'atMention js-open-member';
+    if (knowedUser.userId === Meteor.userId())
+      linkClass += ' me';
+    link = HTML.A({
+      'class': linkClass,
+      // XXX Hack. Since we stringify this render function result below with
+      // `Blaze.toHTML` we can't rely on blaze data contexts to pass the
+      // `userId` to the popup as usual, and we need to store it in the DOM
+      // using a data attribute.
+      'data-userId': knowedUser.userId,
+    }, linkValue);
+
+    content = content.replace(currentMention[0], Blaze.toHTML(link));
+  }
+
+  return HTML.Raw(content);
+}));
+
 Template.viewer.events({
+  'click .js-open-member'(evt, tpl) {
+    const userId = evt.currentTarget.dataset.userid;
+    Popup.open('member').call({ userId }, evt, tpl);
+  },
+
   // Viewer sometimes have click-able wrapper around them (for instance to edit
   // the corresponding text). Clicking a link shouldn't fire these actions, stop
   // we stop these event at the viewer component level.
@@ -81,6 +129,8 @@ Template.viewer.events({
     // by using directly `_blank` attribute in the rendered HTML.
     evt.preventDefault();
     const href = evt.currentTarget.href;
-    window.open(href, '_blank');
+    if (href) {
+      window.open(href, '_blank');
+    }
   },
 });