CODEWITHSUNDEEP
jquery
Alain
Alain

Reputation: 36964

Why this $.isFunction returns false?

I created a jquery function, but $.isFunction seems to always return false if the function name is inside a string.

(function( $ ) {
    $.myTest = function() {
       return true;
    }
})( jQuery );

alert($.isFunction('$.myTest'));

Fiddle : here.

Note : if I remove quotes (eg. alert($.isFunction($.myTest));, it works, but my function is inside a string.

EDIT

This function name is inside a string because I create a plugin to make ajax from parameters inside the dom elements. For example :

        data-route="xxx.php"
        data-lock=".buttonsToLock"
        data-output="#outputContainer"
        data-callback-after="$.myTest"

But I am unable to check if data-callback-after is an existing function.

Any idea?

Thanks

Upvotes: 0

Views: 501

Answers (3)

VisioN
VisioN

Reputation: 145408

You should always pass an object to $.isFunction() method:

alert($.isFunction($.myTest));

Otherwise, you will always receive false, since string is not a function by default.

Upvotes: 6

Mario S
Mario S

Reputation: 11955

Functions will be stored in window so you could try something like this:

$.isFunction(window['myTest']);

But, since you are using "namespaces" you need to do it like this:

$.isFunction(window['$']['myTest']);

Or you can use this function:

function isFunctionByName(functionName, context) {
  var namespaces = functionName.split(".");
  var func = namespaces.pop();
  for(var i = 0; i < namespaces.length; i++) {
    context = context[namespaces[i]];
  }
  return $.isFunction(context[func]);
}

alert(isFunctionByName("$.myTest", window));

http://jsfiddle.net/JqCzH/2/

Upvotes: 2

Blowsie
Blowsie

Reputation: 40535

Looks like you trying to dynamically call functions / callbacks.

You should consider the following approach.

    (function( $ ) {
        window.myTest = function() {
           return true;
        }
    })( jQuery );

var data-route="xxx.php",
    data-lock=".buttonsToLock",
    data-output="#outputContainer",
    data-callback-after="myTest";

    // To run the function 
    window[data-callback-after]();

    // To test the function
    $.isFunction(window[data-callback-after]);

Upvotes: 1

Related Questions