Sharepoint 2013: CRUD operations on Site Columns

Question

So far, I'm able to perform CRUD operations on Lists, I was wondering if it is possible to do it on Site Columns, I've try to find it on the web but I literally found nothing, I dediced to drop a question here just to understand if it is possible or not, in case it is possible can please anyone provide me some sources so I can learn? thanks in advance.

Answer 1

This is doing exactly what you need, I've done it for work as well couple of weeks ago.

var ctx;
        var web;
        var fieldChoice;
        var fieldName;
        var values;

        $(function () {
            SP.SOD.executeOrDelayUntilScriptLoaded(Function.createDelegate(this, function () {
                fieldName = $('#dropdown').find(":selected").text();
                populateValues(fieldName);
            }), 'SP.js');
        });

        function selection() {
            fieldName = $('#dropdown').find(":selected").text();
            populateValues(fieldName);
        }

        function populateValues(fieldName) {
            ctx = SP.ClientContext.get_current();
            web = ctx.get_web();
            fieldChoice = ctx.castTo(web.get_availableFields().getByTitle(fieldName), SP.FieldChoice);
            ctx.load(this.fieldChoice);
            ctx.executeQueryAsync(Function.createDelegate(this, this.OnLoadSuccess), Function.createDelegate(this, this.OnLoadFailed));
        }
        /* Displays the vaules of the array in the textarea */
        function OnLoadSuccess() {
            values = fieldChoice.get_choices();
            $("textarea#textareadisplay").val(values.join("\n"));

        }

        function OnLoadFailed(e, args) {
            alert();
        }

        /* Push the textarea values in an array */
        function addItemsToColumns() {
            values = $('textarea#textareadisplay').val().split('\n');
            columnSpaceDelete();
            updateFieldChoice();
        }

        /* Function to delete empty values in the array */
        function columnSpaceDelete() {
            for (x = 0; x <= values.length - 1; x++) {
                var a = values.indexOf("");
                if (a !== -1) {
                    values.splice(a, 1);
                }
            }
        }

        /* Update the columns values whit the values in the array */
        function updateFieldChoice() {
            fieldChoice.set_choices(values);
            fieldChoice.update();
            ctx.executeQueryAsync(function () { }, function () { });
        }

And the relative HTML:

<select id="dropdown" name="dropdown" onchange="selection()">
            <option value="EngineType_Cylinders">EngineType_Cylinders</option>
            <option value="EngineType_EngineCycle">EngineType_EngineCycle</option>
            <option value="EngineType_EngineFamily">EngineType_EngineFamily</option>
            <option value="EngineType_Euro">EngineType_Euro</option>
            <option value="EngineType_FamilyEvolution">EngineType_FamilyEvolution</option>
            <option value="EngineType_GasEmissionLevel">EngineType_GasEmissionLevel</option>
            <option value="EngineType_Power">EngineType_Power</option>
            <option value="EngineType_PowerSupply">EngineType_PowerSupply</option>
            <option value="EngineType_Use">EngineType_Use</option>
        </select><br />

        <textarea id="textareadisplay"></textarea><br />
        <input type ="button" id="updatebtn" value="Update values" onclick="addItemsToColumns()" />