silverstripe-multiform/code/MultiFormStep.php

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2008-04-18 00:03:51 +02:00
<?php
/**
* MultiFormStep controls the behaviour of a single from step in the multi-form
* process. All form steps should be subclasses of this class, as it encapsulates
* the functionality required for the step to be aware of itself in the form step
* process.
*
* @package multiform
*/
class MultiFormStep extends DataObject {
static $db = array(
'Data' => 'Text' // stores serialized maps with all session information
);
static $has_one = array(
'Session' => 'MultiFormSession'
);
/**
* Centerpiece of the flow control for the form.
* If set to a string, you pretty much have a linear
* form flow - if set to an array, you should
* use {@link getNextStep()} to enact flow control
* and branching to different form steps,
* most likely based on previously set session data
* (e.g. a checkbox field or a dropdown).
*
* @var array|string
*/
protected static $next_steps;
/**
* Each {@link MultiForm} subclass
* needs at least one step which is marked as the "final" one
* and triggers the {@link MultiForm->finish()}
* method that wraps up the whole submission.
*
* @var boolean
*/
protected static $is_final_step = false;
/**
* Title of this step, can be used by each step that sub-classes this.
* It's useful for creating a list of steps in your template.
*
* @var string
*/
protected $title;
/**
* Formfields to be rendered with this step
* (Form object is created in {@link MultiForm}.
* This function needs to be implemented
*
* @return FieldSet
*/
public function getFields() {
user_error('Please implement getFields on your MultiFormStep subclass', E_USER_ERROR);
}
/**
*
* @return FieldSet
*/
public function getExtraActions() {
return new FieldSet();
}
/**
* Get a validator specific to this form.
*
* @return Validator
*/
public function getValidator() {
return null;
}
/**
* Accessor method for $this->title
*/
public function getTitle() {
return $this->title;
}
/**
* Gets a direct link to this step (only works
* if you're allowed to skip steps, or this step
* has already been saved to the database
* for the current {@link MultiFormSession}).
*
* @return string Relative URL to this step
*/
public function Link() {
return Controller::curr()->Link() . '?MultiFormSessionID=' . $this->Session()->ID;
}
/**
* Unserialize stored session data and return it.
* This should be called when the form is constructed,
* so the fields can be loaded with the values.
*/
public function loadData() {
return unserialize($this->Data);
}
/**
* Save the data for this step into session, serializing it first.
*
* @TODO write a code snippet on how to overload this method!
*
* @param array $data The processed data from save() on MultiForm
*/
public function saveData($data) {
$this->Data = serialize($data);
$this->write();
}
/**
* @TODO what does this method do? What is it's responsibility?
*
*/
public function start() {
}
/**
* @TODO what does this method do, in relation to MultiForm->finish() ?
* I thought we were finalising the entire form on MultiForm, and not
* each step?
*/
public function finish() {
}
/**
* Returns the first value of $next_step
*
* @return String Classname of a {@link MultiFormStep} subclass
*/
public function getNextStep() {
$nextSteps = $this->stat('next_steps');
// Check if next_steps have been implemented properly if not the final step
if(!$this->isFinalStep()) {
if(!isset($nextSteps)) user_error('MultiFormStep->getNextStep(): Please define at least one $next_steps on ' . $this->class, E_USER_ERROR);
}
if(is_string($nextSteps)) {
return $nextSteps;
} elseif(is_array($nextSteps) && count($nextSteps)) {
// custom flow control goes here
return $nextSteps[0];
} else {
return false;
}
}
/**
* Returns the next step to the current step in the database.
*
* This will only return something if you've previously visited
* the step ahead of the current step, so if you've gone to the
* step ahead, and then gone back a step.
*
* @return MultiFormStep|boolean
*/
public function getNextStepFromDatabase() {
$nextSteps = $this->stat('next_steps');
if(is_string($nextSteps)) {
$step = DataObject::get($nextSteps, "SessionID = {$this->SessionID}", 'LastEdited DESC');
if($step) return $step->First();
} elseif(is_array($nextSteps)) {
$step = DataObject::get($nextSteps[0], "SessionID = {$this->SessionID}", 'LastEdited DESC');
if($step) return $step->First();
} else {
return false;
}
}
/**
* Accessor method for self::$next_steps
*/
public function getNextSteps() {
return $this->stat('next_steps');
}
/**
* Returns the previous step, if there is one.
*
* To determine if there is a previous step, we check the database to see if there's
* a previous step for this multi form session ID.
*
* @return String Classname of a {@link MultiFormStep} subclass
*/
public function getPreviousStep() {
$steps = DataObject::get('MultiFormStep', "SessionID = {$this->SessionID}", 'LastEdited DESC');
if($steps) {
foreach($steps as $step) {
if($step->getNextStep()) {
if($step->getNextStep() == $this->class) {
return $step->class;
}
}
}
}
}
// ##################### Utility ####################
/**
* @TODO Do we need this? Can't we just check for the return value of getPreviousStep,
* and do boolean logic from that?
*/
public function hasPreviousStep() {
die('MultiFormStep->hasPreviousStep(): Not implemented yet');
}
/**
* Determines whether this step is the final step in the multi-step process or not,
* based on the variable $is_final_step - to set the final step, create this variable
* on your form step class.
*
* @return boolean
*/
public function isFinalStep() {
return $this->stat('is_final_step');
}
/**
* Determines whether the currently viewed step is the current step set in the session.
* This assumes you are checking isCurrentStep() against a data record of a MultiFormStep
* subclass, otherwise it doesn't work. An example of this is using a singleton instance - it won't
* work because there's no data.
*
* @return boolean
*/
public function isCurrentStep() {
if($this->class == $this->Session()->CurrentStep()->class) return true;
}
}
?>