In Moodle, while we use $PAGE->requires->js_init_call() to include a JS function defined in our plugin's module.js file, how can I include external Javascript resources, which we normally include in the <head> tags like:
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>mypage</title>
<script type="text/javascript" src="http://yui.yahooapis.com/2.5.0/build/yahoo-dom-event/yahoo-dom-event.js"></script>
<script type="text/javascript" src="http://yui.yahooapis.com/2.5.0/build/element/element-beta-min.js"></script>
<script type="text/javascript" src="http://yui.yahooapis.com/2.5.0/build/connection/connection-min.js"></script>
<script type="text/javascript" src="http://yui.yahooapis.com/2.5.0/build/tabview/tabview-min.js"></script>
</head>
Use following code to include javascript file in your code:
$PAGE->requires->js()
E.g
$PAGE->requires->js( new moodle_url($CFG->wwwroot . '/local/my_localplugin/myjavascript.js'));
You can use the following code to include a javascript file in your code inside the :
$PAGE->requires->js('/mod/namemodule/socket.io.js',true);
In this way, the file is loaded socket.io.js within the <head> </head>
来源：https://stackoverflow.com/questions/25219176/how-to-include-external-javascript-on-my-moodle-page