Development:lib/formslib.php repeat elements

Template:Formslib 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.

From the phpdoc comments from this moodleform 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
     *                          'type' - PARAM_* constant is value
     *                          'helpbutton' - helpbutton params array is value
     *                          'disabledif' - last three moodleform::disabledIf()
     *                                           params are value as an array
     * @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 array $addstring array of params for get_string for name of button, $a is no of fields that
     *                                  will be added.
     */

This method can be called from within definition(). Here is an example from within chat_mod_form in chat/mod_form.php. You can see this at work if you add a chat form or update a chat form in your course.

        $repeatarray=array();
        $repeatarray[] = &MoodleQuickForm::createElement('header', '', get_string('choice','choice'));
        $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'] = array(
                                   'default'=>0,
                                   'type'=>PARAM_INT,
                                   'disabledif'=>array('limitanswers', 'eq', 0));
        $repeateloptions['option'] = array(
                                   'type'=>PARAM_TEXT,
                                   'helpbutton'=>array('options', get_string('modulenameplural', 'choice'), 'choice'));
        $repeateloptions['optionid'] = array('type'=>PARAM_INT);

        $this->repeat_elements($repeatarray, $repeatno,
                    $repeateloptions, 'option_repeats', 'option_add_fields', 3);