MultiFormMultiStep > A SilverStripe MultiForm Step allowing for a dynamic number of questions/answers. Useful for CMS generated surveys &c.

MultiFormMultiStep.php

<?php

/**
 * MultiFormMultiStep allows answers to be collected for a dynamic number of
 * questions as a single MultiFormStep. This is useful if you have an unknown
 * amount of questions (e.g. dynamically generated by a CMS based survey maker).
 *
 * Define the next and previous steps as usual -- but to get to the next step,
 * isLastQuestion must return true. Similarly, to get to the previous step
 * isLastQuestion must return true.
 * 
 * The following is simplified example assuming Questions are contained in a 
 * DataList of MultiFormQuestion objects. Answers can be yes/no. I have
 * extended to for more complicated scenarios such as dynamic answer texts
 * and user-selectable questionnaires.
 * 
 * MultiFormQuestion extends DataObject with QuestionText and ID fields 
 * QuestionnaireFormStepFirst extends MultiFormStep and is the previous step
 * QuestionnaireFormStepLast  extends MultiFormStep and is is the next step
 * 
 * @author Brice Burgess @iceburg.net
 * 
 */



class MultiFormMultiStep extends MultiFormStep {
    
    private $initialized = false;
    private $answers = null;
    private $skip_fields = array('question-id');

    
    /**
     * @var RIMQuestionnaire $questionnaire
     */
    private $questionnaire = null;
    
    /**
     * 
     * @var RIMQuestion $current_question
     */
    private $current_question = null;
    
    
    public function setForm($form) {
        
        $ret = parent::setForm($form);
        
        $this->initializeStep();
        
        return $ret;

    }
    

    public function getNextStep() {
        return ($this->isLastQuestion()) ?
            'QuestionnaireFormStepLast' :
            __CLASS__;
        
    }
    
    public function getPreviousStep() {
        return($this->isFirstQuestion()) ?
            'QuestionnaireFormStepFirst' :
            __CLASS__;
        
    }
    
    public function getFields() {
        
        if(!$this->initialized) {
            $this->initializeStep();
        }
        
        if(!$this->current_question) {
            return $this->redirectHome('Questionnaire reached an invalid state.');
        }
        
        $answer_key = 'answer:' . $this->current_question->ID;
       
                
        $fields = new FieldList(
            new LiteralField('question-text', $this->current_question->QuestionText),
            new HiddenField('question-id','question-id',$this->current_question->ID)
        );
        
        $fields->add(
            new OptionsetField($answer_key, 'Please Choose', array(1 => 'yes', 0 => 'no')));
                

        return $fields;
    }
    
    
    public function loadData() {
        // cache loadData as $this->answers to avoid successive serialization
        if(!$this->answers) {
            $this->answers = parent::loadData();
        }
        
        return $this->answers;
    }
    

    public function saveData($data) {
        
        // save multiple answers for this step
        $answers = $this->loadData();
        $data = array_merge((array) $answers, $data);
        
        foreach($this->skip_fields as $key) {
            if(isset($data[$key])) {
                unset($data[$key]);
            }
        }

        return parent::saveData($data);
        
    }
    
    public function Link() {
        
        $question_id = null;
        $request = $this->getForm()->getController()->getRequest();
        if($request->requestVar('action_prev')) {
            $question_id = ($this->current_question) ?
                $this->getPreviousQuestionID() :
                $this->getLastQuestionID();
        }
        elseif($request->requestVar('action_next')) {
            $question_id = ($this->current_question) ? 
                $this->getNextQuestionID() : 
                $this->getFirstQuestionID();
        }

        return ($question_id) ? 
            Controller::join_links($this->form->getDisplayLink(), "?question-id={$question_id}&MultiFormSessionID={$this->Session()->Hash}") :
            Controller::join_links($this->form->getDisplayLink(), "?MultiFormSessionID={$this->Session()->Hash}");
    }
    
    public function getNextQuestionID() {
        
        $next = false;
    
        foreach(MultiFormQuestion::get() as $question) {
            if($next) {
                return $question->ID;
            }
            
            if($question->ID == $this->current_question->ID) {
                $next = true;
            }
        }
    
        return 0;
    }
    
    public function getPreviousQuestionID() {

        $prev_question_id = 0;
        
        
        foreach(MultiFormQuestion::get() as $question) {
            if($question->ID == $this->current_question->ID) {
                return $prev_question_id;
            }
            $prev_question_id = $question->ID;
        }
        
        return 0;
    }
    
    
    /**
     * Set the current question by ID
     * @param int $id
     */
    public function setQuestionByID($id) {
        if($question = DataObject::get_by_id('MultiFormQuestion', $id))
            $this->setQuestion($question);
    }
    
    /**
     * Set the current question 
     * @param MultiFormQuestion $question
     */
    public function setQuestion($question) {
        $this->current_question = $question;
    }
    
    
    
    public function initializeStep() {
        
        if($this->initialized) return;
        
        // set the question
        $request = $this->getForm()->getController()->getRequest();
        
        if($question_id = $request->requestVar('question-id')) {
            $this->setQuestionByID((int) $question_id);
        }

        // mark initialized
        $this->initialized = true;
    }
    
    public function isLastQuestion() {
        return ($this->getLastQuestionID() == $this->current_question->ID);  
    }
    
    
    public function isFirstQuestion() {
        return ($this->getFirstQuestionID() == $this->current_question->ID);
    }
    
    
    public function getFirstQuestionID() {
        $first = MultiFormQuestion::get()->first();
        
        return $first->ID;
    }
    
    public function getLastQuestionID() {
        $last = MultiFormQuestion::get()->last();
        
        return $last->ID;
    }
    
    
    public function redirectHome($msg = null) {
        $msg = ($msg) ? '?msg=' . urlencode($msg) : '';
        
        $controller = $this->getForm()->getController();
        $controller->redirect($controller->Link() . $msg);
        return new FieldList();
    }
    
}