Annotate selectors with "!" to mean "must match"

Reported by:	skrul	Owned by:	john
Priority:	low	Milestone:	1.4
Component:	selector	Version:	1.3.2
Keywords:		Cc:
Blocked by:		Blocking:

Description

A suggestion from a new jQuery user: Several times I've run into problems where my selector expression was not matching due to a bug, but it was not obvious since it is perfectly valid to traverse and manipulate an empty jQuery object.

So I propose adding a syntax to the selector expression that means "if this does not match, throw an exception." I think the "!" symbol is appropriate since it reminds me of CSS's "!important".

For example, $("#myid!") would throw an exception if #myid was not found.

Thoughts?

Attachments (0)

Change History (4)

Changed March 02, 2009 01:20AM UTC by dmethvin comment:1

You could also accomplish this with a plugin:

jQuery.fn.orDie = function(msg){
  if ( !this.length)
    alert("Nothing selected! "+(msg||""));
  return this;
};

Changed March 08, 2009 10:03AM UTC by dantman comment:2

I don't like the idea of using !, a ! reminds me far to much of not.

$('#foo!.foo');

Changed August 09, 2009 01:18AM UTC by dmethvin comment:3

component:	unfilled → selector
owner:	→ john
priority:	major → trivial

Changed October 29, 2010 05:10PM UTC by rwaldron comment:4

priority:	trivial → low
resolution:	→ invalid
status:	new → closed

! is reserved for representing "not"

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