Adding a valid e-mail address field
In this recipe, we will add a rule that ensures the user has entered a valid e-mail address. This rule should be fairly self-explanatory. It simply checks that the text is in the standard "user@example.com" format.
Getting ready
Please refer to the first recipe in this chapter for details on how to prepare a QuickForm web form which is the basis of this recipe.
How to do it...
Add the following code to our form definition in validation_form.php just after the field definition:
$mform->addElement('text', 'mytext6', 'Email');
$mform->addRule('mytext6', 'Email', 'email', null, 'client');
Now we can test this rule by entering a domain name instead of a valid e-mail address. We notice that we are unable to submit the form, and our warning message is displayed as seen in the following screenshot:
How it works...
We used the validation type email which requires no format option, as the format of an e-mail address is pre-defined and is therefore not configurable...
