In this recipe, we will add a rule that accepts only numeric characters, that is, digits 0-9. This could be useful, for example, when the user is required to enter a reference number or a currency value.
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', 'mytext9', 'Numeric'); $mform->addRule('mytext9', 'Numeric', 'numeric', null, 'client');
When we test out this new rule by entering non-numeric characters (in this example, we entered the string abc), we see ...