RestAPI & Tags

We do a lot of such stuff in our community.  Here is an exaple that works for us to enforce the subject has enough "meat" to it and adds a tag if the subject contains a certain pattern.  This can be adapted to check a pull down instead of the subject.

<@liaAddScript>
;(function ($) {
    $('.lia-button-Submit-action').bind('click', function() {
        var tag_field = document.getElementById("lia-tags");
        var subject_field = document.getElementById("lia-subject");
        if (subject_field.value == "CASE: 6XXXXXXXX: Device is experiencing high CPU") {
            subject_field.value = "";
        } else if (subject_field.value.match(/^CASE:\s+6[0-9]{8}\s*:?\s*$/)) {
            alert("Please specify an additional summary in the Subject.");
            subject_field.focus();
            return false;
        } else if (subject_field.value.match(/.*6[0-9]{8}\b.*/)) {
            var srnum = subject_field.value.match(/.*(6[0-9]{8})\b.*/)[1];
            var tags = tag_field.value;
            var tagsre = new RegExp(".*\btz:link:" + srnum + "\b.*");
            if (!tags.match(tagsre)) {
                if (tags == '') {
                    tag_field.value = 'tz:link:' + srnum;
                } else {
                   tag_field.value = tags + ',tz:link:' + srnum;
                }
            }
        }
        subject_field.focus();
    });
})(LITHIUM.jQuery);    
</@liaAddScript>

This does a few things.  First, it checks the subject field to see if it matches a pattern corresponding to one of our case IDs.  If so, a custom tag is applied in the format of "tz:link:CASE_NUMBER".  If the only thing in the subject is a case number, then it forces the user to enter an additional title.  All of this logic is bound to the submit button using jQuery.

Note: we don't use the REST API here since the topic hasn't been started yet.  We don't have a thread or message ID.  However, we can inject tags on post.