未捕获的TypeError：无法调用null的方法“ get”

Question

I know there are many threads about this issue and i ve been looking for my specific case but i have not found anything relevant.

I am implementing this javascript cashRegister effect in this page but i get this error msg

"Uncaught TypeError: Cannot call method 'get' of null"

It points to the raw 18 of the plugin.js:

var current_value = this.element.get('text');

What might cause this error? What i should try to do now?

Thanks

Answer 1

I think your problem is at this line:

var total = $('total');

The selector total means "find elements with the name 'total'". What you really want is to find the element with the id of "total," so do this instead:

var total = $('#total');

Edit :

I think some of the confusion stems from the fact that the $ in the site you're referencing is the $ from MooTools. In your page, you are including jQuery, which has an entirely different $ object that behaves differently. I believe that $('total') is how you select an element by ID in MooTools.

I'm not sure how you can load both libraries without having naming conflicts, but if you can figure that out, make sure you're using MooTools to select the total instead of jQuery.

Edit 2 :

After a bit of research (I'm unfamiliar with MooTools), I see that you could replace $('total') with:

document.id('total')