Question

Is there a (maybe undocumented) placeholder like $.noop for the use in jQuery concatenations?

To use in something like the following:

$('selector')[true ? 'method' : '<function that does nothing>']().doSomething();

I’ve tried a lot and ended up with this:

$.fn.noop = function(){ return this; };

But maybe there’s already such a function in the jQuery core?

Answer 1

Option one:

Use $.fn.splice. It’s there and it’s always present, but it’s also undocumented (so it may not be present in the future), unreadable, and requires there be no arguments.

Option two:

$.fn.noop = function(){return this}. Reliable, readable, predictable, fast. About the only reason to prefer #1 is development time.

Option three (preferred): Use a plugin for conditionals, which are about the only reason to desire a chainable no-op, such as the Iff plugin by Ben Alman (or write your own).

Pro: turns

 ... [condition?'method':'noop']() ...

into:

 ... .iff(condition).method().end() ...

That is, it’s more readable than #2, AND you’re not restricted to one call. You can even traverse within iff or nest your conditionals as long as you properly unwind the stack.

Cons: it’s a plugin, and you’ll need to fetch it; it requires the methods you call are no-ops when operating on the empty collection. All standard jQuery functions (except add) are.