Detect when input has a 'readonly' attribute

Question

I want to throw an alert when an input has a 'readonly' attribute. I have tried this:

  if($('input').attr('readonly') == 'readonly'){      alert("foo");   } 

I think that 'if' is not even the best way to do it.

Answer 1

fastest way is to use the .is() jQuery function.

if ( $('input').is('[readonly]') ) { } 

using [readonly] as a selector simply checks if the attribute is defined on your element. if you want to check for a value, you can use something like this instead:

if ( $('input').is('[readonly="somevalue"]') ) { } 

Answer 2

Since JQuery 1.6, always use .prop() Read why here: http://api.jquery.com/prop/

if($('input').prop('readonly')){ } 

.prop() can also be used to set the property

$('input').prop('readonly',true);  $('input').prop('readonly',false);