Advanced elements

Form elements can be marked as 'advanced'. This has the effect that they are hidden initially.

To control whether an element is advanced, you can use the setAdvanced method on the MoodleQuickForm instance and set a specific element as being advanced, for example:

Marking an element as advanced

$mform->addElement(
    'select',
    'display',
    get_string('displaymode', 'choice'),
    $CHOICE_DISPLAY
);
$mform->setAdvanced('display');

It is also possible to unset the advanced status of a field - the setAdvanced function takes a second, boolean, parameter which defaults to true. By passing a false value, the element's advanced flag will be removed, for example:

Marking an element as advanced

// Mark a field as not advanced after it was previously marked as advanced.
$mform->setAdvanced('display', false);

danger

You should be careful about marking too many elements as advanced.

For more information on the risks of this, see the advice in Designing usable forms.

Location of Show and hide links

Whenever you mark a form element as advanced, then the Show / hide advanced links are shown automatically at relevant points within the form.

The Show advanced and Hide advanced links are currently displayed at the top right of all fieldsets containing advanced controls.

Setting a name

When adding a header element, the second parameter to addElement() is a name field. You should pass a unique name for each header.

If the name is not specified, or is not unique then this can have a range of unintended impacts, including marking multiple sections of the form as advanced. It is strongly encouraged to always name headers.

An example of incorrect behaviour

An empty name is passed to these headings

$mform->addElement(
    'header',
    '',
    get_string('miscellaneoussettings', 'form')
);
$mform->addElement(
    'select',
    'display',
    get_string('displaymode', 'choice'),
    $CHOICE_DISPLAY
);
$mform->setAdvanced('display');

// Because this section has a non-unique name (an empty string),
// the advanced flag set for the display element in the previous
// section will also apply here.
$mform->addElement(
    'header',
    '',
    get_string('anothersection', 'form')
);

Marking an entire section as advanced

The setAdvanced function can mark an entire section as advanced by specifying the name of the header at the top of the section, for example:

Marking an entire section as advanced

$mform->addElement(
    'header',
    'miscellaneoussettingshdr',
    get_string('miscellaneoussettings', 'form')
);
$mform->setAdvanced('miscellaneoussettingshdr');

In this example, all fields from this header until the next header will be marked as advanced.