RequireJS：如何卸载以前加载的javascript文件？ 又名排他性依赖关系？ 还是重置RequireJS？

Question

I have 2 javascript files that cannot co-exist. If a user click on one button, it loads one js file. If a user clicks another button, it loads the other file. But the last one needs to be unloaded first

Here is generally what I have:

//pseudocode
if user clicks button one
    loadScript(one);
if user clicks button two
    loadScript(two);

//not psuedocode
function loadScript(name)
{
      var javascriptLoc = name + "/config.js";

      //Unload any scripts that were previously loaded by requirejs
      require.undef(); //HELP

      //once config.js is loaded by requirejs...
      require([javascriptLoc], function(util) {

          //do stuff

      });
}

Is there a way to unload one/config.js and load two/config.js instead ? Then when a user clicks on "one", it would load one/config.js instead of two/config.js?

Other ways to word the question:

• what do I do in requirejs when I have exclusive dependancies ...

• how do I deal with conflict resolution in requirejs...

• how do I reset or unload scripts previously loaded by requirejs...

Answer 1

Strictly speaking, browsers don't let you unload JavaScript files. If you load a file a.js that says:

var a = 345;

There is no command in JS/HTML that can undo that. (See also here , and here )

You can load a new set of JS commands that negates the effect of the first file, for example:

if (typeof a === "undefined") 
   var a = 34;
else
   a = 34;

This is starting to get complicated though, isn't it? It might be easier to redesign the modules so reloading isn't necessary, for example:

function option1() {
}
function option2() {
}

//if user clicks button 1
currentOption = option1();
//if user clicks button 2
currentOption = option2();