Multi-select managed metadata column - get distinct values

Question

I have a list with multi-select managed metadata column. How, preferably using search REST api, get all distinct values from this column from all list rows?

Answer 1

Using following JSOM you can get terms by term set name.

function getTermsByTermSetName(termSetName, callback) {                  
    var context = SP.ClientContext.get_current();               
    var session = SP.Taxonomy.TaxonomySession.getTaxonomySession(context);
    var termStore = session.getDefaultSiteCollectionTermStore(); 
    termSets = termStore.getTermSetsByName(termSetName,1033); 
    context.load(session);
    context.load(termStore); 
    context.load(termSets);

    context.executeQueryAsync(       
    function () {
        var termSetEnum = termSets.getEnumerator();
        if(termSetEnum.moveNext()){
            var currentTermSet = termSetEnum.get_current();      
            //Load terms         
            var terms = currentTermSet.get_terms();      
            context.load(terms);         
            context.executeQueryAsync(       
            function () {        
                var termsEnum = terms.getEnumerator();
                var termsList = [];      
                while (termsEnum.moveNext()) {       
                    var currentTerm = termsEnum.get_current();       
                    var termName = currentTerm.get_name();       
                    var termId = currentTerm.get_id();       
                    termsList.push(termName);        
                }   
                //alert(termsList); 
                callback(termsList);
            },       
            function () {        
                //failure to load terms.
            });
        }        
    },       
    function () {        
        //failure to load current term set       
    });
}

getTermsByTermSetName("term set name", function(terms) {
//execute your logic to bind terms
});