jQuery RegEx test returning undefined

Question

I've toyed with this for the last hour and am finally asking for some advice/help on what's causing this issue. I'm creating a small fallback using RegEx, the first input works fine, but the second returns undefined. Here's the HTML:

<input type="email" value="[email protected]" />
<input type="text" pattern="[A-Za-z]{3}" value="ABC" />

You'll see from the jsFiddle and Console that it prints 'Success' for the type="email" input, but returns undefined for the pattern fallback. I basically want to reuse the same function and pass the parameters into it and get the value returned dynamically.

I have a feeling this might be the issue line:

var patternFallback = $(this).attr('pattern')

... Perhaps it somehow needs 'converting' for the JS to read it as RegEx?

Here's my jsFiddle if you can help, and thank you! The script is a section of the full code, which includes the problem area, the loop through elements and the variables I'm passing through the function: http://jsfiddle.net/fTk7e/

Many thanks in advance.

You have $(this).attr('pattern') outside of any sort of event handler. Therefore this is not your element. — gen_Eric
– gen_Eric, Commented Jun 11, 2013 at 20:03
Ah yes sorry, that's meant to be inside the loop. However, the answer below is what I needed. — Stephen Jenkins
– Stephen Jenkins, Commented Jun 11, 2013 at 20:07

nderscore · Accepted Answer · 2013-06-11 20:28:19Z

2

var patternFallback = $(this).attr('pattern')

The value of 'this' where you are calling the function is a reference to the document object. You need to move this variable definition inside your each() call. This is why you're getting undefined.

And you should be creating a regular expression out of the string. You can't call .test() on a string.

var patternFallback = RegExp($(this).attr('pattern'));

edited Jun 11, 2013 at 20:28

answered Jun 11, 2013 at 20:08

nderscore

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1 Comment

Stephen Jenkins Over a year ago

Thanks nderscore, slight type 'RexExp' though! :)

claustrofob · Accepted Answer · 2013-06-11 20:05:06Z

1

new RegExp($(this).attr('pattern'));

answered Jun 11, 2013 at 20:05

claustrofob

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Comments

Erik Bongers · Accepted Answer · 2013-06-11 20:13:23Z

0

I agree with Rocket Hazman. Give the inputs an ID and test it that way.

<input id="myEmailId" type="email" value="[email protected]" />
<input id="myTextId" type="text" pattern="[A-Za-z]{3}" value="ABC" />

And in javascript:

var patternFallback = $("#myTextId").attr('pattern');

answered Jun 11, 2013 at 20:13

Erik Bongers

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1 Comment

Stephen Jenkins Over a year ago

Thanks Erik. I had meant to include the $(this) within the $.each loop, and what I needed was the new RegExp($(this).attr('pattern'));

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