A simple script to check whether TinyMCE is active and visible in WordPress Dashboard

tinyMCE-check.js

jQuery(document).ready(function ($) {

	'use strict';

	/*
	References
	http://codeblow.com/questions/method-to-check-whether-tinymce-is-active-in-wordpress/
	https://wordpress.org/support/topic/tinymceactiveeditorgetcontentcontent-does-not-work-with-tinymce-advanced
	 */

	var tinymceActive, cannedResponse, editorType;

	/* This is an object passed using wp_localize_script that returns either "tinymce" or "html" (from wp_get_user_setting) */
	editorType = wpascr.editor;

	$('.wpas-canned-response').click(function (e) {
		e.preventDefault();

		tinymceActive = (typeof tinyMCE != 'undefined') && tinyMCE.activeEditor && !tinyMCE.activeEditor.isHidden();
		cannedResponse = $(this).attr('data-message');

		/* Check if TinyMCE is active */
		if (tinymceActive) {

			/* Check version of TinyMCE */
			if (tinymce.majorVersion < 4) {
				tinyMCE.execInstanceCommand('wpas_reply', 'mceInsertContent', false, cannedResponse);
			} else {
				var edv4 = tinyMCE.get('wpas_reply');
				edv4.insertContent(cannedResponse);
			}

		} else {

			/* Append canned response to existing textarea value */
			$('#wpas_reply').val(function (i, val) {
				return val + cannedResponse;
			});

		}
	});

});