Updating SharePoint list or library field which consist of MMS (Managed Metadata or Taxonomy) column with Angular JS and JSOM

UpdateSharePointFieldWithMMSColumn.js

(function () {
    'use strict';

    // define controller
    var controllerId = "MMSDevCtrl";

    angular
    .module('app')
    .controller(controllerId, ['$q', mmsDevController]);

    // create controller
    function mmsDevController($q) {

        //global var
        var vm = this;

        //value definitions
        var siteUrl = 'http://win2012/sites/MSSDevTest';
        var listName = 'MyDocumentLibrary';
        var fieldName = 'MMSColName'; //MMS Column name
        var itemIdUpdating = 1; // Item to be udated
        var termLabel = 'IT'; //'';

        //add metadata column to sharepoint
        vm.submitMetadata = function () {
            // function for update managed metadata column
            SetManagedMetaDataField();
        }

        // Setting managed metadata to SharePoint List or Library
        function SetManagedMetaDataField() {
            var context = new SP.ClientContext(siteUrl);
            //Get item form ID
            var list = context.get_web().get_lists().getByTitle(listName); //listName
            var item = list.getItemById(itemIdUpdating); //itemID
            var field = list.get_fields().getByInternalNameOrTitle(fieldName); //fieldName
            var txField = context.castTo(field, SP.Taxonomy.TaxonomyField);

            //loading context
            context.load(field);
            context.load(txField);
            context.load(item);

            //excute async
            context.executeQueryAsync(
                Function.createDelegate(this, function () {
                    var termSetId = txField.get_termSetId().toString();
                    var termId;
                    getTermIdForTerm(function success(id) {
                        termId = id;
                        var value = item.get_item(fieldName);
                        var terms = new Array();

                        // If column in multivalued 
                        if (txField.get_allowMultipleValues()) {
                            var enumerator = value.getEnumerator();
                            while (enumerator.moveNext()) {
                                var tv = enumerator.get_current();
                                terms.push(tv.get_wssId() + ";#" + tv.get_label() + "|" + tv.get_termGuid());
                            }
                            terms.push("-1;#" + termLabel + "|" + termId);
                            termValueString = terms.join(";#");
                            termValues = new SP.Taxonomy.TaxonomyFieldValueCollection(context, termValueString, txField);
                            txField.setFieldValueByValueCollection(item, termValues);
                        }
                        else {// If column in single valued
                            var termValue = new SP.Taxonomy.TaxonomyFieldValue();
                            termValue.set_label(termLabel);
                            termValue.set_termGuid(termId);
                            termValue.set_wssId(-1);
                            txField.setFieldValueByValue(item, termValue);
                        }
                        // Define other columns
                        item.set_item('Title', 'New Item with good hope!');
                        var dateValue = new Date('28-8-2016');
                        item.set_item('DateTimeColumn', dateValue);
                        // Update item
                        item.update();
                        //Execute query
                        context.executeQueryAsync(
                        function () {
                            console.log('field updated  with MMS column #TechCentro');
                        }, function (sender, args) {
                            console.error(args.get_message() + '\n' + args.get_stackTrace());
                        });
                    }, function (sender, args) {
                        console.log(args.get_message() + '\n' + args.get_stackTrace());
                    }, context, termLabel, termSetId);
                })
            , Function.createDelegate(this, function (err) {
                console.error(err.get_message());
            }));
        }
        // Getting ID of the Term
        function getTermIdForTerm(success, error, clientContext, term, termSetId) {
            var termId = "";
            var tSession = SP.Taxonomy.TaxonomySession.getTaxonomySession(clientContext);
            var ts = tSession.getDefaultSiteCollectionTermStore();
            var tset = ts.getTermSet(termSetId);
            var lmi = new SP.Taxonomy.LabelMatchInformation(clientContext);
            lmi.set_lcid(1033);
            lmi.set_trimUnavailable(true);
            lmi.set_termLabel(term);
            var termMatches = tset.getTerms(lmi);
            //contexr loading with taxanomy values
            clientContext.load(tSession);
            clientContext.load(ts);
            clientContext.load(tset);
            clientContext.load(termMatches);
            clientContext.executeQueryAsync(
            function () {
                if (termMatches && termMatches.get_count() > 0)
                    termId = termMatches.get_item(0).get_id().toString();
                success(termId);
            }, function (sender, args) {
                error(args);
            });
        }

    };

})();