This issue was resolved within the library - https://github.com/mbenford/ngTagsInput/pull/239
There is no on-tag-click handler for the ng-tags-input such that a user clicks on a tag to elicit a function call via an angular expression:
<!-- does not exist -->
<tags-input on-tag-click="handleTagClick(data)"></tags-input>
As of mid-May 2015, this issue was resolved within the library https://github.com/mbenford/ngTagsInput/pull/239. Now you can use it with the directive like so:
<tags-input on-tag-clicked="callback()"