limitation of RegularExpressionValidator?

PeterPeiGuo · January 12th, 2009, 07:15 PM

As we all know that FileUpload control does not support file type restriction out of the box, and you have to do it on your own, for example through RegularExpressionValidator.

That's fine, so I used a validator with this expression

Code:

^.+?\.(doc|xls|jpg|ppt|pdf)$

, and it worked like charm. However if I change the regexp to

Code:

\.(doc|xls|jpg|ppt|pdf)$

, it became broken. That's strange though, as logically speaking, anything matches the first regexp also satisfies the second one...

Is there some sort of wierd restriction came with RegularExpressionValidator?

Imar · January 16th, 2009, 05:41 PM

Can you define "it is broken"?

Imar

PeterPeiGuo · January 16th, 2009, 07:05 PM

Quote:

Originally Posted by Imar

Can you define "it is broken"?

I use one example to explain this:

With the first regexp, if you select a .pdf file, it passes the validation;
With thw second regexp, if you select a .pdf file, the error message shows up.

Old Pedant · January 17th, 2009, 12:39 AM

Well, it works fine in JavaScript. Are you asking for only server-side validation??? I'd think that a client-side validator would work.

Here it is in pure HTML/JS:

Code:

<script>
var r1 = /^.+?\.(doc|xls|jpg|ppt|pdf)$/i
var r2 = /\.(doc|xls|jpg|ppt|pdf)$/i

function Check(fld)
{
    alert( "Test 1: " + r1.test(fld.value) + "\nTest 2: " + r2.test(fld.value) );
}
</script>
<form>
<input onchange="Check(this);">
<p>
<input onchange="Check(this);">
</form>

Did you possibly forget the "i" (or equivalent...for ignore case) in the second instance???

Imar · January 17th, 2009, 05:26 AM

I agree it's weird. Don't know why that doesn't work with a RegularExpressionValidator....

Imar

PeterPeiGuo · January 20th, 2009, 02:07 PM

run into another one of those situation earlier today. I have a textbox and it only accepts allnumeric string less than 14 characters long, and cannot be empty. So I used a RegularExpressionValidator, and the regexp is

Code:

^(\d{1,14})$

, but that didn't work.

I ended up use regexp

Code:

^(\d+)$

, and set MaxLength of the textbox to 14.

Old Pedant · January 20th, 2009, 04:36 PM

Not clear to me why you think you need parentheses in either of those.

You should be able to just do

Code:

^\d{1,14}$

On the other hand, I don't see how the parentheses hurt.

PeterPeiGuo · February 13th, 2009, 12:44 AM

Thanks Old Pedant. I end up went with java script, it is easier. RegularExpressionValidator + FileUploader seemed to be a bad combination. In many ways, that combination is not a decent solution.