lib/formslib.php repeat elements

This function adds a repeating group of elements. An array index starting with a zero index will be added to the elementname so that the form will return arrays of submitted values.

Also on the form there will be a button to add extra elements to the form. The form page reloads with extra form elements. This involves no javascript.

Contents 1 Overview 2 The elements to repeat 3 The number of repeats 4 Examples

Overview

Most of the necessary information is in the phpdoc comment for the repeat_elements() method:

    /**
     * Method to add a repeating group of elements to a form.
     *
     * @param array $elementobjs Array of elements or groups of elements that are to be repeated
     * @param integer $repeats no of times to repeat elements initially
     * @param array $options Array of options to apply to elements. Array keys are element names.
     *                      This is an array of arrays. The second sets of keys are the option types
     *                      for the elements :
     *                          'default' - default value is value
     *                          'helpbutton' - helpbutton params array is value
     *                          'disabledif' - last three moodleform::disabledIf()
     *                                           params are value as an array
     *                          'rule' - array of arguments for addRule for the elements
     *                                     or a string with a rule name which will be a rule name
     *                                     which be validated client side and which has a default error 
     *                                     message.
     * @param string $repeathiddenname name for hidden element storing no of repeats in this form
     * @param string $addfieldsname name for button to add more fields
     * @param int $addfieldsno how many fields to add at a time
     * @param string $addstring the label for the add more fields button.
     */

The elements to repeat

Are in the $elementobjs array, with any options passed in the $options array.

WIthin these fields, for example, within the element labels or the Defaults (since Moodle 2.3) you can use {no} to represent which element number this is, counting from 1.

The number of repeats

$repeats is the number of repeats to show initially. $addfieldsno is the number of elements to add whenever the user clicks the 'add more fields' button. $addstring is the label for this button. It can use the {no} placeholder, this time for saying how many repeats will be added. $repeathiddenname is the name to use for the hidden form field that records how many repeats there are.

Examples

Here is some code using repeat_elements() from inside definition() method of the add or update a Choice form:

//-------------------------------------------------------------------------------
        $repeatarray=array();
        $repeatarray[] = &MoodleQuickForm::createElement('header', '', get_string('choice','choice').' {no}');
        $repeatarray[] = &MoodleQuickForm::createElement('text', 'option', get_string('choice','choice'));
        $repeatarray[] = &MoodleQuickForm::createElement('text', 'limit', get_string('limit','choice'));
        $repeatarray[] = &MoodleQuickForm::createElement('hidden', 'optionid', 0);
 
        if ($this->_instance){
            $repeatno=count_records('choice_options', 'choiceid', $this->_instance);
            $repeatno += 2;
        } else {
            $repeatno = 5;
        }
 
        $repeateloptions = array();
        $repeateloptions['limit']['default'] = 0;
        $repeateloptions['limit']['disabledif'] = array('limitanswers', 'eq', 0);
        $mform->setType('limit', PARAM_INT);
 
        $repeateloptions['option']['helpbutton'] = array('options', get_string('modulenameplural', 'choice'), 'choice');
        $mform->setType('option', PARAM_TEXT);
 
        $mform->setType('optionid', PARAM_INT);
 
        $this->repeat_elements($repeatarray, $repeatno,
                    $repeateloptions, 'option_repeats', 'option_add_fields', 3);

For other examples, have a look at the question type editing forms. They may extensive use of repeat_elements().