load.js

function LoadDocument(template) {
  var serviceURL = "/ReportingCloud/Template?TemplateName=" + template;

  // call the "GET Template" controller method with a template name
  $.ajax({
      type: "GET",
      url: serviceURL,
      contentType: 'application/json',
      success: successFunc,
      error: errorFunc
  });

  function successFunc(data, status) {

      streamType = TXTextControl.StreamType.InternalUnicodeFormat;

      // create the proper StreamType based on the extension
      if (template.endsWith("docx")) {
          streamType = TXTextControl.StreamType.WordprocessingML;
      }
      else if (template.endsWith("doc")) {
          streamType = TXTextControl.StreamType.MSWord;
      }
      else if (template.endsWith("rtf")) {
          streamType = TXTextControl.StreamType.RichTextFormat;
      }

      // load the document into the widget
      textControl1.loadDocument(streamType, data);

      // enable the save button and set heading
      $("#saveBtn").removeAttr("disabled");
      loadedDocument = template;
      $("#documentName").text(loadedDocument);
  }

  function errorFunc(data, success) {
      console.log(data);
  }
}