Is it possible to use a single javascript tag for loading an external js file and calling its function?_问答_开发者

Is it possible to use a single javascript tag for loading an external js file and calling its function?

开发者 https://www.devze.com 2023-03-13 08:51 出处：网络

I am writing a third party javascript (my.js) that can be inserted in a HTML page usin开发者_如何学Gog script tag. I want to achieve the following:

my.js gets loaded (which has a function myFunc(params))
myFunc() gets called with appropriate params (parameters can change)
putting my.js script in head is not an option

What is the best approach that I can use?

The problem is that you can't really pass parameters w/ just 1 script tag pointing to an external file, so you would have to get them from some element in the DOM:

The html:

<html>
<body>
  <script src="my.js"></script>
  <input id="params" type="hidden" value="'param1', 'param2', 'param3'" />
  <div id="result"></div>
</body>
</html>

The javascript:

function myfunc() {
var doc = document,
 params = doc.getElementById("params").value.split(","); // make an array of params

doc.getElementById("result").innerHTML = params.toString();
}
window.onload = myfunc;

Honestly though, this is a kludge. As mentioned before by Felix, you should probably just use 2 script tags -- One to get the external js file and one to call the function with the parameters you need.

You can pass parameters in via the query string and parse them out dynamically.

For example, your script tag becomes: <script src="my.js?foo=bar"></script>

You can then get the value of the URL using:

var scripts = document.getElementsByTagName('script');
var url = scripts[ scripts.length - 1 ].getAttribute('src');

Because of the order JS is loaded by the browser, the last script on the page (while your script is executing during load) should always be your script.

Then you parse the query string. There are a bunch of questions on Stack Overflow dealing with that. Ex: Parse query string in JavaScript