Promisified GlideAjax

When client scripts rely on multiple GlideAjax calls, callback nesting can quickly become hard to read and maintain. A small Promise wrapper gives you cleaner flow, easier composition, and centralized error handling.

Promise wrapper for GlideAjax

This helper:

• accepts Script Include name, method name, and params object
• resolves with answer
• rejects when the response is malformed or parsing fails

/**
 * Promisified version of GlideAjax
 * @param {string} scriptInclude - Name of client-callable Script Include
 * @param {string} methodName - Method name inside Script Include
 * @param {Object} params - Params object, for example: { sysparm_user_id: '...' }
 * @returns {Promise<string>} Resolves with "answer" returned by the Script Include
 */
function uGlideAjaxAsync(scriptInclude, methodName, params) {
	return new Promise(function(resolve, reject) {
		try {
			var ga = new GlideAjax(scriptInclude);
			ga.addParam('sysparm_name', methodName);

			for (var key in (params || {})) {
				if (Object.prototype.hasOwnProperty.call(params, key)) {
					ga.addParam(key, params[key]);
				}
			}

			ga.getXML(function(response) {
				try {
					var xml = response && response.responseXML;
					var root = xml && xml.documentElement;
					if (!root) {
						reject(new Error('GlideAjax response did not contain XML documentElement'));
						return;
					}

					resolve(root.getAttribute('answer'));
				} catch (parseError) {
					reject(parseError);
				}
			});
		} catch (setupError) {
			reject(setupError);
		}
		});
}

Usage example

uGlideAjaxAsync('UserUtils', 'getManagerSysId', {
	sysparm_user_id: g_form.getValue('requested_for')
})
	.then(function(managerSysId) {
		if (managerSysId) {
			g_form.setValue('manager', managerSysId);
		}
	})
	.catch(function(error) {
		console.error('Failed to fetch manager via GlideAjax', error);
		g_form.addErrorMessage('Unable to get manager information right now.');
	});

Why this is useful

• Cleaner orchestration for sequential async calls.
• Better error propagation than deeply nested callbacks.
• Reusable helper you can keep in one UI Script.

If your instance supports modern syntax, you can use the same helper with async/await for even cleaner client scripts.