Can I validate a string with only alphanumeric, space and underscore chars only

[etabalon]

Good day!

Can I validate a string and only accepts upper/lower case alphanumeric, space, dash and underscore chars only?

I'm trying to validate a server name so users cannot use like $ or % characters as part of the server name.

Thanks,

Enrique

[Abhinay Erra]

You can write an onChange client script on the server name field

if(newValue.match(/[a-zA-z-_\s]/g).length!=newValue.length){

alert('Please enter only upper/lower case alphanumeric, space, dash and underscore chars');

}

//Edit: Modified script a little bit

[Vladi]

Abhinay, thank you for sharing the solution. I modified it to exclude space and add dash, and it works for me 95%

What is not working, is if user adds only special characters in the field, script does not alert and does not go further either. I suspect this is because in such a case string is null and .length can't calculate on that. Any ideas, how to get around it?

if(newValue.match(/[a-z0-9-]/ig).length!=newValue.length) {

g_form.setValue('email_address', "");

...}

[drjohnchun]

Hi Vladmir - as you suspected, it's the match() that returns null in case of no match and subsequently results in an error. You can test for the null condition, but I'd just use

if (!/^[a-z0-9-]+$/i.test(newValue)) {
   g_form.setValue('email_address', "");
   ...
}

[Vladi]

Thanks a lot, John. Expression written this way did the trick.