In this recipe, we will define a field that has a maximum length constraint. This could be used when you require concise summary text to be entered, for example, when screen "real estate" is at a premium. Alternatively, it would be useful for situations when the particular column of a database into which the data will be saved only accepts a certain number of characters.
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', 'mytext2', 'Max length 5'); $mform->addRule('mytext2', ...