在我自己的类中使用JavaScript库（underscore.js）

Question

I'm trying to call a method from the underscore.js library within a class of my own. Something like this:

document.write('<scr'+'ipt type="text/javascript" src="Helpers/underscore-min.js" ></scr'+'ipt>');
function MyObject(object){
    this.object = object;

    this.RandomMethod = function(object)
    {
        var result = _.isEqual(object, this);
    }
}

I am able to use it if I do it outside of the object declaration, but if it try to access it like this, the object does not exist.

Can somebody help?

Answer 1

The script you are adding has not had time to load yet since scripts are loaded asynchronously. To test this, try adding a timeout to delay the script execution:

document.write('<scr'+'ipt type="text/javascript" src="Helpers/underscore-min.js" ></scr'+'ipt>');
setTimeout(function() {
    //your code here
}, 2000); //delay for 2 seconds to give script time to laod

This isn't a solution, just a way to verify the problem. If this is what's going on check out this article:

4 ways to dynamically load external JavaScript(with source)

You may want to employ the fourth option. It allows you to determine when the script has finished loading.