JavaScript/CoffeeScript binding techniques for different environments
Suppose you want to do something similar to this:
# won't work, context is lost here
$.ajax({
url: '/foo',
success: myObj.myMethod
});Client with jQuery:
success: $.proxy(myObj, 'myMethod')Client with underscore:
success: _.bind(myObj.myMethod, myObj)Node.js or client with newer browser:
success: myObj.myMethod.bind(myObj)Vanilla JS, any browser:
success: function(){ return myObj.myMethod.apply(myObj, arguments); }CoffeeScript:
success: -> myObj.myMethod(arguments...)Written by Pavel Pravosud
Related protips
5 Responses
Looks like you want to use => instead of -> here (coffeescript)
@matthewwithanm apply is the only was to pass all arguments directly to a function. If you know an easier way to do the same thing, please tell (there is none actually).
@koehr no, => preserve the current context, which is unimportant.
@matthewwithanm you're absolutely right, in this particular example a much simple code like that could work:
success: function(a1, a2, a3){ return myObj.myMethod(a1, a2, a3); }
but I wanted to make an example with kinda more unified and general way of doing binding where you're not concerned by the number of arguments.
I thought @koehr was correct that you should use => in the CoffeeScript example, because I assumed the $.ajax block was inside myObj. Great post, but this could be clearer. :)
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