isFunction() always false in jQuery

so I'm using qtip for a super simple tool tip implementation.

I'm not including qtip on every page, only the pages that needed, so I'm trying to check for qtip's existence before calling it.

 /*
  * Tool Tip
  * inits qtip 开发者_C百科on any link with class="tt"
  */
  if( $.isFunction( $.qtip ) ){
  $(".tt").qtip();
  }

I've no idea what this isn't working. it's always returning false. Any ideas? Thx.

IMO, you should check

if($.isFunction($.fn.qtip))

try this:

if( $.isFunction( $.fn.qtip ) ){
    $(".tt").qtip();
}

as plugins reside in the $.fn object

I prefer using the typof operator since it's not jQuery dependent.

if(typeof window.myFunction == 'function') {
    // function exists, so we can now call it
    myFunction();
}

On a side note it's a great way to "extend" javascript on "If" something exists (like form validation)

If the implementation is consistent accross all you your pages, then just put

$(function(){
    $(".tt").qtip();
}

at the bottom of the qtip.js file, that way, it is executed whenever qtip is included.

if( $.isFunction(qtip) ){
 //bla bla
}

try this or with commas

if( $.isFunction("qtip") ){
     //bla bla
    }

Try removing the "$." before the qtip in the isFunction check.