Adding a field length within in a specified range

In this recipe, we will learn how to add a rule to ensure the length of text entered falls into a specified range of numbers of characters. Again, this could be used to validate information, such as a telephone number whose length must fall in a particular range to be accepted.

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', 'mytext4', 'Length 3-5');
$mform->addRule('mytext4', 'Length 3-5', 'rangelength', array(3,5), 'client');

Now we can test this rule in a web browser and we will notice that if we enter text whose length falls outside the required range, our warning message will be displayed and the user will be unable to proceed as seen in the following screenshot:

How it works...

We used the validation...