<div btf-markdown="mess.content" ng-show="!mess.viewSource"></div>

  <pre ng-show="mess.viewSource && !mess.editMode">{{ mess.content }}</pre>

  <textarea class="form-control" id="nvMessTitre" rows="7" placeholder="Contenu du message" ng-model="mess.content" ng-show="mess.viewSource && mess.editMode"></textarea>