In this recipe, we will add a rule that accepts only alphanumeric characters, that is, only the digits 0-9 and letters a-z in upper or lower case.
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.
Add the following code to our form definition in
validation_form.php, just after the field definition:
$mform->addElement('text', 'mytext8', 'Alpha-numeric'); $mform->addRule('mytext8', 'Alpha-numeric', 'alphanumeric', null, 'client');
Now we can test this new rule by entering text including non-alphanumeric characters. In the following example, we have enclosed our text in non-alphanumeric ...