lib/formslib.php Form Definition

definition()

The definition of the elements to be included in the form, their 'types' (PARAM_*), helpbuttons included, etc is all included in a function you must define in your class definition();

definition() is used to define the elements in the form and this definition will be used for validating data submitted as well as for printing the form. For select and checkbox type elements only data that could have been selected will be allowed. And only data that corresponds to a form element in the defintion will be accepted as submitted data.

Use Fieldsets to group Form Elements

You use code like this to open a fieldset with a legend.

//-------------------------------------------------------------------------------
        $mform->addElement('header', 'nameforyourheaderelement', get_string('titleforlegened', 'modulename'));

You can't yet nest these visible fieldsets unfortunately. But in fact groups of elements are wrapped in invisible fieldsets.

You close a fieldset with this code. You tell addStopFieldsetElements the element before you wish to end the fieldset. A fieldset is automatically closed if you open a new one. You need to use this code only if you want to close a fieldset and the subsequent form elements are not to be enclosed by a fieldset  :

        //possibly at the start of definition();
	$mform    =& $this->_form;
        $renderer =& $mform->defaultRenderer();


        $renderer->addStopFieldsetElements('buttonar');

disabledIf

For any element or groups of element in a form you can conditionally disable the group or individual element depending on conditions.

You can use $mform->disabledIf($elementName, $dependentOn, $condition = 'notchecked', $value=null)

• elementname can be a group. If you specify a group all elements in the group will be disabled (if dependentOn is in elementname group that is ignored and not disabled). These are the element names you've used as the first argument in addElement or addGroup.
• dependentOn is the actual name of the element as it will appear in html. This can be different to the name used in addGroup particularly but also addElement where you're adding a complex element like a date_selector. Check the html of your page. You typically make the depedentOn a checkbox or select box.
• $condition will be notchecked, checked, eq or if it is anything else then we test for neq.
• If $condition is eq or neq then we check the value of the dependentOn field and check for equality (==) or nonequality (!=) in js
• If $condition is checked or notchecked then we check to see if a checkbox is checked or not.

setType

PARAM_* types are used to specify how a submitted variable should be cleaned. These should be used for get parameters such as id, course etc. which are used to load a page and also with setType(); method. Every form element should have a type specified except select, radio box and checkbox elements, these elements do a good job of cleaning themselves (only specified options are allowed as user input).

Most Commonly Used PARAM_* Types

These are the most commonly used PARAM_* types and their proper uses. More types can be seen in moodlelib.php starting around line 100.

• PARAM_CLEAN is deprecated and you should try to use a more specific type.
• PARAM_TEXT should be used for cleaning data that is expected to be plain text. It will strip all html tags. But will still let tags for multilang support through.
• PARAM_NOTAGS should be used for cleaning data that is expected to be plain text. It will strip *all* html type tags. It will still *not* let tags for multilang support through. This should be used for instance for email addresses where no multilang support is appropriate.
• PARAM_RAW means no cleaning whatsoever, it is used mostly for data from the html editor. Data from the editor is later cleaned before display using format_text() function. PARAM_RAW can also be used for data that is validated by some other way or printed by p() or s().
• PARAM_INT should be used for integers.
• PARAM_ACTION is an alias of PARAM_ALPHA and is used for hidden fields specifying form actions.

addElement

Use the addElement method to add a an element to a form. The first few arguments are always the same. The first param is the type of the element to add. The second is the elementname to use which is normally the html name of the element in the form. The third is often the text for the label for the element.

Some examples are below :

        $mform->addElement('text', 'name', get_string('forumname', 'forum'));

        $mform->addElement('select', 'type', get_string('forumtype', 'forum'), $FORUM_TYPES);

        $mform->addElement('selectyesno', 'maxbytes', get_string('maxattachmentsize', 'forum'));

        $mform->addElement('modgrade', 'scale', get_string('grade'), false);

        $mform->addElement('checkbox', 'ratingtime', get_string('ratingtime', 'forum'));

        $mform->addElement('date_time_selector', 'assesstimestart', get_string('from'));

        $mform->addElement('date_selector', 'assesstimefinish', get_string('to'));

addGroup

A 'group' in formslib is just a group of elements that will have a label and will be included on one line.

For example typical code to include a submit and cancel button on the same line :

        $buttonarray=array();
        $buttonarray[] = &MoodleQuickForm::createElement('submit', 'submitbutton', get_string('savechanges'));
        $buttonarray[] = &MoodleQuickForm::createElement('submit', 'cancel', get_string('cancel'));
        $mform->addGroup($buttonarray, 'buttonar', '', array(' '), false);

You use the same arguments for createElement as you do for addElement. Any label for the element in the third argument is normally ignored (but not in the case of the submit buttons above where the third argument is not for a label but is the text for the button).

Here's an example of putting a date_selector (which is itself a group of elements) and a checkbox on the same line, note that you can disable every element in the group using the group name 'availablefromgroup' but it doesn't disable the controlling element the 'availablefromenabled' checkbox:

        $availablefromgroup=array();
	$availablefromgroup[]=&MoodleQuickForm::createElement('date_selector', 'availablefrom', '');
	$availablefromgroup[]=&MoodleQuickForm::createElement('checkbox', 'availablefromenabled', '', get_string('enable'));
        $mform->addGroup($availablefromgroup, 'availablefromgroup', get_string('availablefromdate', 'data'), ' ', false);
        $mform->disabledIf('availablefromgroup', 'availablefromenabled');