I’m using the Validator from jQuery Tools to validate my form (why jquery tools? because they are lightweight and use semantic HTML5 Tags, input-types and params for validation) but I have one problem:
I want to let jQuery Tools Validator test/validate a input-field only if it is not empty — but the field is not required.
On fields that have to be tested/validated, I can use required="required" and it validates … now I have a text-input-field where the user can input a URL, this field is not required BUT if the user adds some data into that field, the field should validate with pattern="https?://.+" to get sure the user is entering a valid url… if I add the pattern-parameter and no required-parameter, jQuery Tools Validator does test/validate nonetheless and I’m not able to submit the form until I entered a valid URL — even if I do not want to enter a URL at all!
You could try modifying your regex to allow the empty string, such as