jQuery proxy / partial application

jq-proxy.js

var aps = Array.prototype.slice;

jQuery.proxy = function( fn, context ) {
  var tmp, proxy, partialArgs;

  // Handle jQuery.proxy( contextObj, nameString ) signature.
  if ( typeof context === "string" ) {
    tmp = context;
    context = fn;
    fn = context[ tmp ];
  }

  // Get args to be partially applied, only if necessary.
  if ( arguments.length > 2 ) {
    partialArgs = aps.call( arguments, 2 );
  }

  // Native bind.
  if ( jQuery.support.nativeBind ) {
    if ( partialArgs ) {
      proxy = fn.bind.apply( fn, [ context ].concat( partialArgs ) );
    } else {
      proxy = fn.bind( context );
    }

  // No native bind.
  } else if ( partialArgs ) {
    proxy = function() {
      var args = arguments.length ? partialArgs.concat( aps.call( arguments ) ) : partialArgs;
      return fn.apply( context, args );
    };
  } else {
    proxy = function() {
      return arguments.length ? fn.apply( context, args ) : fn.call( context );
    };
  }

  // Set the guid of unique handler to the same of original handler, so it can be removed
  proxy.guid = fn.guid = fn.guid || proxy.guid || jQuery.guid++;

  // So proxy can be declared as an argument
  return proxy;
};