unable to get property 'get_current' of undefined or null reference

Root Cause: You are missing SP.js, some references.
Solution:

	$(document).ready(function () {
	var hostweburl = decodeURIComponent(getQueryStringParameter("SPHostUrl"));
	var scriptbase = hostweburl + '/_layouts/15/';
	$.getScript(scriptbase + 'SP.Runtime.js',
	function () {
	$.getScript(scriptbase + 'SP.js',
	function () { $.getScript(scriptbase + 'SP.RequestExecutor.js', CallJS); }
	);
	}
	);
	});
	function CallJS() {
	alert('hi');
	}
	function getQueryStringParameter(param) {
	var params = document.URL.split("?")[1].split("&");
	var strParams = "";
	for (var i = 0; i < params.length; i = i + 1) {
	var singleParam = params[i].split("=");
	if (singleParam[0] == param) {
	return singleParam[1];
	}
	}
	}

view raw gistfile1.js hosted with ❤ by GitHub