Add Site Columns to Site Content Type on Host Web using JSOM

'use strict';

var context = SP.ClientContext.get_current();

var hostWebUrl, hostWebContext;

// This code runs when the DOM is ready and creates a context object which is

// needed to use the SharePoint object model

$(document).ready(function () {

    hostWebUrl = decodeURIComponent(getQueryStringParameter("SPHostUrl"));

    hostWebContext = new SP.AppContextSite(context, hostWebUrl);

});



// Retrieve a query string value

function getQueryStringParameter(paramToRetrieve) {

    var params = document.URL.split("?")[1].split("&");

    for (var i = 0; i < params.length; i = i + 1) {

        var singleParam = params[i].split("=");

        if (singleParam[0] == paramToRetrieve) return singleParam[1];

    }

}

//Add Site Columns to Content Type

var hostWebContentTypes;

var contentTypeName = 'Employee'; // Name of the Content Type where Colums will be added

var columnsInternalName = ["EmployeeId", "EmployeeName"]; //Internal Names of the Site Columns

var createdColumns = new Array();

function addColumnsToContentType() {

    var hostWeb = hostWebContext.get_web();

    //Get the columns that need to be added to Content type and store the objects in an Array.

    for (var iCreatedFieldsCounter = 0; iCreatedFieldsCounter < columnsInternalName.length; iCreatedFieldsCounter++) {

        createdColumns[iCreatedFieldsCounter] = hostWeb.get_fields().getByInternalNameOrTitle(columnsInternalName[iCreatedFieldsCounter]);

        context.load(createdColumns[iCreatedFieldsCounter]);

    }

    //Get Host Web Content type Collection

    hostWebContentTypes = hostWeb.get_contentTypes();

    context.load(hostWebContentTypes);

    context.executeQueryAsync(

  function () {

      //Call function to add columns to Content Type

      addColumns(contentTypeName, columnsInternalName, createdColumns);

  },

  function onItemsRefetchedFail(sender, args) {

      alert('Failed to fetch columns and Content Type. Error:' + args.get_message() + '\n' + args.get_stackTrace());

  });

}

// Add columns

function addColumns(ctypeName, fieldsInternalName, createdFields) {

    //Find the Content Type and then add Fields to it

    var createdContentType;

    var contentTypeEnumerator = hostWebContentTypes.getEnumerator();

    while (contentTypeEnumerator.moveNext()) {

        var contentType = contentTypeEnumerator.get_current();

        if (contentType.get_name() === ctypeName) {

            createdContentType = contentType;

            var fieldRef = new Array();

            for (var iAddFieldsCounter = 0; iAddFieldsCounter < createdFields.length; iAddFieldsCounter++) {

                fieldRef[iAddFieldsCounter] = new SP.FieldLinkCreationInformation();

                fieldRef[iAddFieldsCounter].set_field(createdFields[iAddFieldsCounter]);

                createdContentType.get_fieldLinks().add(fieldRef[iAddFieldsCounter]);

                createdContentType.update(true);

            }

            context.load(createdContentType);

            context.executeQueryAsync(onAddFieldToContentTypeSuccess, onAddFieldToContentTypeFail);

        }

    }

}

function onAddFieldToContentTypeSuccess() {

    alert('Site Columns added to Content Type.');

}

function onAddFieldToContentTypeFail(sender, args) {

    alert('Failed to add Site Columns to Content Type. Error:' + args.get_message() + '\n' + args.get_stackTrace());

}

//End