Validation ideas

[AnotherWannabe]

I thought I was being clever by using a standard PHP function to check and see if all the characters in a field were alphanumeric. I never even thought about the fact that I need to allow spaces!!!

Is there a way to make exceptions? Say in one field I wanted alphanumeric, but spaces were allowed…and in another field, I allowed alphanumeric and spaces and commas, periods, exclamations…

Most of what I’m finding online is related to JavaScript, but JS can be turned off…not good for security!
I need to validate on the server side. Thanks.

[phphelp]

You can use regular expressions to validate your fields. For example, if you want to allow alphanumeric with spaces, you can do this:
[php]if(!preg_match("~^[0-9a-z\x20]+$~i",$field1)){
echo ‘Invalid field1’;
}
[/php]

For alphanumeric and spaces and commas, periods, exclamations try:
[php]if(!preg_match("~^[0-9a-z\x20.,!]+$~i",$field2)){
echo ‘Invalid field2’;
}[/php]

More complex example, if you want to validate field to always start with 1 letter, followed with 4 to 10 alphanumeric or dashes:
[php]if(!preg_match("~^[a-z][0-9a-z-]{4,10}$~i",$field3)){
echo ‘Invalid field3’;
}[/php]