I'm building a contact form in SilverStripe.
When testing validation, if I leave the required fields blank and hit submit, those input fields will be added a .holder-required class. Even if I reload the page, they won't disappear. (actually the error messages *** is required will stay there after reload too. I just stopped the messages from showing).
I've searched the whole project folder, but there's no file that even has holder-required in it.
Where does the .holder-required class come from?
The reason why you couldn't find holder-required is because it technically doesn't exist in the SilverStripe codebase, it actually is a class that is concatenated together from two strings.
In a FormField, there is a function called "extraClass" which adds these classes to the field.
Below is the snippet of code from the FormField class:
public function extraClass() {
$classes = array();
$classes[] = $this->Type();
if($this->extraClasses) {
$classes = array_merge(
$classes,
array_values($this->extraClasses)
);
}
if(!$this->Title()) {
$classes[] = 'nolabel';
}
// Allow custom styling of any element in the container based on validation errors,
// e.g. red borders on input tags.
//
// CSS class needs to be different from the one rendered through {#link FieldHolder()}.
if($this->Message()) {
$classes[] .= 'holder-' . $this->MessageType();
}
return implode(' ', $classes);
}
What this tells us is that for a message that appears for a field, it will append holder-{Whatever_Your_Message_Type_Is} as an extra class.
The reason why $this->Message() would still be set after a page reload is that the error information is actually saved to the session for that form.
Below is a snippet from the Form class which is what calls the FormField::setError(), the function that sets the message property on the form field.
public function setupFormErrors() {
$errorInfo = Session::get("FormInfo.{$this->FormName()}");
if(isset($errorInfo['errors']) && is_array($errorInfo['errors'])) {
foreach($errorInfo['errors'] as $error) {
$field = $this->fields->dataFieldByName($error['fieldName']);
if(!$field) {
$errorInfo['message'] = $error['message'];
$errorInfo['type'] = $error['messageType'];
} else {
$field->setError($error['message'], $error['messageType']);
}
}
// load data in from previous submission upon error
if(isset($errorInfo['data'])) $this->loadDataFrom($errorInfo['data']);
}
if(isset($errorInfo['message']) && isset($errorInfo['type'])) {
$this->setMessage($errorInfo['message'], $errorInfo['type']);
}
return $this;
}
I've had a bit more of a browse of the Form code, it should be clearing the errors after it is rendering the form. There are two functions part of the form class, clearMessage and resetValidation.
The function clearMessage is called when rendering the form template through forTemplate. I do not see any usage of the resetValidation function throughout the SilverStripe CMS or Framework codebases.
You may need to potentially call one or the other in your code if under your circumstances the message is not clearing.
Related
How do I get the CodeIgniter form validation to validate the $_SESSION if there is no passed form data? I tried manually setting the $_REQUEST variable, but it doesn't seem to work.
i.e. I have a function search in the controller which validates the form input passed, and either returns you to the previous page with errors, or else moves you onto the next page. But I want this function to also work if you previously filled out this page, and the info is stored in the $_SESSION variable.
function search () {
$this->load->library("form_validation");
$this->form_validation->set_rules("flightID", "Flight Time", "required|callback_validFlightID");
$this->form_validation->set_rules("time", "Flight Time", "required|callback_validFlightTime");
$this->setRequest(array("flightID", "time"));
// adding session check allows for inter-view navigation
if ($this->form_validation->run()) {
// some application logic here
$this->load->view("seats", $data);
} else {
$this->logger->log($_REQUEST, "request");
// redirect back to index
$this->index();
}
}
function setRequest () {
// make sure none of the parameters are set in the request
foreach ($vars as $k) {
if (isset($_REQUEST[$k])) {
return;
}
}
foreach ($vars as $k) {
if (isset($_SESSION[$k])) {
$_REQUEST[$k] = $_SESSION[$k];
}
}
}
You can store the form post info in a session using the following codeigniter functions
$formdata = array(
'flightID' => $this->input->post('flightID'),
'time' => $this->input->post('time')
);
$this->session->set_userdata($formdata);
and the information can be retrieved with the following
$this->session->userdata('flightID')
$this->session->userdata('time')
form_validation works directly with $_POST, so use that instead of $_REQUEST.
What you're trying to do is setting Post values manually which is not natively
supported by CodeIgniter. So what we're doing first is extending the core.
Create a new file (MY_Input.php) and paste the following contents into it:
class MY_Input extends CI_Input{
function set_post($key, $value)
{
$_POST[$key] = $value;
}
}
That's a very basic implementation of your purpose but it's enough to test around. You might want to extend it to make it fit your needs (f.e. allowing the input of arrays).
So now. In your controller you can check if something has been posted by a user. If not you'll be just setting the post variable manually with your new method of the Input class.
class Some_Controller extends CI_Controller{
public function index()
{
// The user hasn't filled out a field?
if(!$this->input->post('a_key'))
{
// Let's set the postfield to the value of a session key
$this->input->set_post('a_key', $this->session->userdata('mystoredkey'));
}
}
}
After having set your postfield manually, it can be handled by the form validation library as it is meant to be.
That should be your way to go :)
You can really do some pretty things if you're not afraid of hacking the core. Many people are, don't be one of them!
Happy coding
In my current application, I would like to color the select options red when they contain faulty information (aka not validated). When a form element contains one or more errors, it should have an error class (so I can style accordingly). I tried looping through the elements, and seeing if they validated, but this gets very ugly very quickly.
How would I get this done in a better way?
Thanks
Edit: This is my current workaround (and gets the job done, but dirtily)
$post = $request->getPost();
foreach ($contactForm->getElements() as $element) {
if (!$element->isValid($post[$element->getName()])) {
$element->setAttrib('class', 'error');
}
}
Here are a couple of thoughts...
Instead of calling isValid on every form element, you can validate your whole form with isValid, and then loop over your elements as you are in your question, but instead use if ($element->hasErrors()) to determine if you need to add the error class to the element.
You may want to extend from Zend_Form and add a helper method to your new Form class that does this for you. For example, add a method called highlightErrorElements() or something like that and if you have an unsuccessful call to $form->isValid(), you can then simply call $form->highlightErrorElements() which will loop over each form element and see if it has errors and apply the style if necessary.
Example:
<?php
class Application_Form_Base extends Zend_Form
{
public function __construct()
{
// this is where i normally set up my decorators for the form and elements
// additionally you can register prefix paths for custom validators, decorators, and elements
parent::__construct();
// parent::__construct must be called last because it calls $form->init()
// and anything after it is not executed
}
public function highlightErrorElements()
{
foreach($this->getElements() as $element) {
if($element->hasErrors()) {
$element->setAttrib('class', 'error');
}
}
}
}
Somewhere, in a controller...
$form = new Application_Form_Register(); // this extends Application_Form_Base
if ($form->isValid($this->getRequest()->getPost())) {
// add user etc
} else {
$form->highlightErrorElements();
// other error logic
}
$this->view->form = $form;
Okay, the best way I know to describe the scenario is to first give the example:
Say I have a page called index.php;
At the very top before the <html> tag, one can find;
<?php session_start();
$_SESSION['user_id'] = 1234;
require_once "db.con.php";
?>
Inside that of the <body> tag, one can find:
<div id="div_ajax">
<?php require_once "ajax.php"; ?>
</div>
Now inside the ajax.php page, there is a single button that when clicked will make an ajax request. After the request is made, a simple Db query statement to select user information based on the user_id will be made. The thing is, after the AJAX request, it seems as if the user_id session and the already included Db connection is "lost".
I know I can use a conditional statement to check for AJAX request and just add the lines...
session_start();
require_once "db.con.php";
..at the top of the ajax.php page, but I'm wondering if there's a better way to do this? I don't want to always have to add those two lines to every ajax called PHP page. It sort of defeats the purpose of having the lines on the master page (index.php) to begin with. I guess I can use one ajax called page and just include a bunch of case statements, but still wondering if there's a better way.
Thanks a lot.
As far as my experience goes, I think your problem can be solved with something called the FrontController pattern.
The basic idea is that you're whole application always calls the same file, index.php for instance (also called the single point of entry).
index.php then performs all the tasks that you need on every single page (like starting the session or including your library classes) and then calls the page you want to requested.
This could look something like this: (Can't test it now)
index.php:
<?php
session_start();
$_SESSION['user_id'] = 1234;
require_once("db.con.php");
if($_REQUEST['Request_Type'] == 'website'){
require_once("header.html");
switch($_REQUEST['Request_Url']){
case 'SomePage':
require('SomePage.php');
break;
case 'SomeOtherPage':
require('SomeOtherPage.php');
break;
default:
require('ajax.php');
}
require_once("footer.html");
}elseif($_REQUEST['Request_Type'] == 'ajax'){
switch($_REQUEST['Ajax_Function']){
case 'ProcessButton':
require('ProcessButton.php');
break;
}
}
?>
ajax.php
echo '<input type="button" onClick="ajaxRequest(\"index.php\",\"ProcessButton\")" Value="ClickMe!" />';
The ajaxRequest() Javascript function would have to send an Ajax Request to index.php setting the parameters
Request_Type = 'ajax'
Ajax_Function = 'ProcessButton'
I don't think that there is a better way, but that doesn't mean that there isn't.
Just a couple of notes from reading your question:
1) Use wrapper files for all of your header information. So, at the beginning of your page, put:
require_once('package.php'); // that's what I call mine
Then in package, I have:
require_once('session.start.php');
require_once('db.con.php');
That way, all your pages are accessing the same thing. If you ever need to change it, it's a lot easier.
There is a speed difference between require_once, include_once, include and require. I don't know how significant it is. Frameworks include like 60+ files when they make a page, so I've always assumed its not too bad.
The session information is stored in a folder on your server. PHP defaults it to /tmp (which you should change to a private folder / not web accessible).
Make sure that you are validating any information sent to the AJAX. Remember that it is just like its own web page, so any permissions or database sensitive information should be protected all the same.
"I guess I can use one ajax called page and just include a bunch of case statements, but still wondering if there's a better way."
The controller pattern is pretty good for this type of thing. Having a bunch of case statements in one file is hard on your maintenance. When you switch to having files that only have 1 or 2 functions in them, your life will get so much simpler.
Depending on the size of your project, you may want to implement a framework. Check out MVC frameworks. If I don't implement a framework, I still implement a controller pattern.
I lifted this from my blog. What I use now doesn't even look like this, but it started here:
In the Presentation layer, I am determining which elements I want to implement. For each element that I want to implement, I initiate the controller, like so:
$controller = new Controller();
$context = $controller->getContext();
$context->addParam('action', 'login');
$template->setContent( $controller->process() );
I am using the Controller from PHP Objects, Patterns, and Practice 3rd Ed by Matt Zandstra with my own modifications.
Here is what happens:
My presentation layer gets a new controller object.
The Controller object's constructor automatically creates a new CommandContext object.
The CommandContext is automatically going to load up the request variables as a Parameter, so I don't even need to worry about form data until I get to the Logic layer and need to validate and process it.
In the presentation layer, I load up any additional context parameters (or the information that I want to pass on to the controller), including most importantly, the action that I want to be taken by the Controller.
To pass the information on, I call $controller->process(). In the Logic layer, I can use a default "execute" or make a different command. So, in the Presentation layer, I set the action to "Login" which forces the login command and login view pages to open, and the command defaults to execute, but it could be anything.
When I call process, it triggers the CommandFacotry. The CommandFactory is going to first initiate a new Template child object, such as a side bar div box or main body context. It makes this determination with an optional flag that I can pass to the Controller.
The CommandFactory is then going to open up the Command file and pass the template and the context as objects to the Logic layer.
abstract class Command {
}
class CommandContext {
private $params = array();
private $error = "";
function __construct(){
$this->params = $_REQUEST;
}
function addParam( $key, $val ){
$this->params[$key] = $val;
}
function get( $key ){
return $this->params[$key];
}
function issetCheck( $key ){
if( ! empty( $this->params[$key] ) ){
return true;
}
return false;
}
function setError( $error ){
$this->error = $error;
}
function getError(){
return $this->error;
}
}
class CommandNotFoundException extends Exception { }
class CommandFactory {
private static $dir = 'include/classes/command/';
static function getCommand( $action = 'Default', $flag = 0 ){
switch( $flag ){
case 1:
$template = new TemplateQuickViewOnly();
break;
case 2:
$template = new TemplateQuickViewToggle();
break;
default:
$template = new TemplateMainBodyOnly();
break;
}
if( preg_match ( '/\W/', $action ) ){
throw new Exception("illegal characters in action");
}
$class = UCFirst(strtolower($action))."Command";
$file = ROOT_PATH."".self::$dir."{$class}.php";
if( ! file_exists( $file ) ){
throw new CommandNotFoundException( "could not find '$file'" );
}
include_once( $file );
if( ! class_exists($class) ){
throw new CommandNotFoundException( "no '$class' class located" );
}
$cmd = new $class( $template );
return array( $cmd, $template );
}
}
class Controller {
private $context;
function __construct(){
$this->context = new CommandContext();
}
function getContext(){
return $this->context;
}
function process( $method = 'execute', $flag = 0 ){
list( $cmd, $template ) = CommandFactory::getCommand( $this->context->get('action'), $flag );
if( ! $cmd->$method( $this->context ) ){
// handle failure
// $template->setMessage( UCFirst($this->context->get('action')).' failed to execute.');
return $template->getMessage();
}else{
// success dispatch view
return $template->getMessage();
}
}
}
The Logic layer is in a fixed directory. An instance of the object has already been instatiated by the Controller layer, which means the constructor has been triggered. Further, the controller layer already called the method "execute" (default) or another method, such as "getLoginForm". Also, note that when the Controller calls the method "execute", it is also passing the CommandContext to the method so we have stuff to work with.
class LoginCommand extends Command {
public function __construct( ){ }
function execute ( CommandContext $context ){
if( $context->get('login_user_name') == 'demo' ){
$this->view->setMessage('Success is true!');
return true;
}
return false;
}
function getLoginForm( CommandContext $context ){
$this->view->setMessage('Second sucess is even more true!');
return true;
}
}
You seem confused.
AJAX requests are separate requests for a webpage, nothing you did in the index.php on the server side will be available in the subsequent requests (except for any variables in the session). It works like this:
Request is sent for index.php from the browser
Server runs index.php (storing user_id in the session) and returns the HTML output to the browser at the end, the PHP script finishes and all resources are freed.
User clicks on button, creating a new request for another PHP file, say ajax.php
Server runs ajax.php and returns whatever is output to the browser. Again the PHP script finishes and all resources are freed.
Another way to think about this: From the server side, an AJAX request is almost the same as if you'd just pointed your browser to ajax.php directly.
I've been having problems created modular reusable components in my Zend Framework app. In this case I'm not referring to Zend Framework modules but rather the ability to have a reusable MVC widgety thing if you like. The problems I'm having may be very particular to my implementation, but I'm completely happy to throw it out and start again if someone can point me in the right direction. Anyway, specifics and code will hopefully explain things better and even if what I'm doing is not the best way it should show what I'm trying to achieve:
A simple example is a Mailing List sign up form. I want to include this on several pages of the site which use different Controllers and this presents a few problems in how to process the data and return relevant messages. I don't want to do either of the following as they really smell:
Create a base controller with the form processing in and extend (Bad)
Duplicate form processing code in relevant controllers (Even worse!)
The clean way to go feels to me to create a new Controller to process the mailing list form data, use a View Helper to easily output the form and relevant markup into the desired pages and then redirect back to the page where signup occurred once the form has been processed. However, I'd like to use the form validation provided by Zend_Form, which means I'd need to pass the form object back to the view helper somehow if validation fails but in the same request. I'm currently doing this by setting it as a variable on the view and then forwarding back to the previous page rather than redirecting, which is ok(ish). If validation is ok then I'd prefer to use a redirect back to the original page. I'm having trouble doing this though as I'd like to pass messages back to the component about the state of signup. Normally I'd use the FlashMessenger Action Helper, I could namespace it in this case so messages didn't clash with other page data, but I can't access it from within a View Helper. So currently I'm forwarding in this case too. I'd much prefer a redirect to prevent form resubmissions if a user refreshes the page and to keep the URL clean. I realise I essentially want to have a mini MVC dispatch process within a page and I think that's what the action stack is for? I really don't know much about this though and any pointers would be greatly appreciated. Here's my current code:
Controller:
<?php
class MailingListController extends Zend_Controller_Action {
public function insertAction() {
$request = $this->getRequest();
$returnTo = $request->getParam('return_to');
if(!$request->isPost() || (!isset($returnTo) || empty($returnTo))) {
$this->_redirect('/');
}
$mailingList = new Model_MailingList();
$form = new Form_MailingList();
$returnTo = explode('/', $returnTo);
if($form->isValid($_POST)) {
$emailAddress = $form->getValue('email_address');
$mailingList->addEmailAddress($emailAddress);
$this->view->mailingListMessages = $mailingList->getMessages();
$this->view->mailingListForm = "";
}
else {
$this->view->mailingListForm = $form;
}
$this->_forward($returnTo[2], $returnTo[1], $returnTo[0]);
}
}
return_to is a string containing the current URI (module/controller/action), which is generated in the View Helper. I'd prefer to redirect inside the $form->isValid($_POST) block.
View Helper:
<?php
class Zend_View_Helper_MailingList extends Zend_View_Helper_Abstract {
public function mailingList($form, $messages = "") {
if(!isset($form)) {
$request = Zend_Controller_Front::getInstance()->getRequest();
$currentPage = $request->getModuleName() . '/' . $request->getControllerName() . '/' . $request->getActionName();
$form = new Form_MailingList();
$form->setAction('/mailing-list/insert');
$form->setCurrentPage($currentPage);
}
$html = '<div class="mailingList"><h2>Join Our Mailing List</h2>' . $form;
$html .= $messages;
$html .= '</div>';
return $html;
}
}
Getting an instance of the Front Controller in the View Helper isn't ideal but I'd prefer to encapsulate as much as possible.
If I have a form object where validation has failed I can pass it back into the helper to output with error messages. If I have some messages to render I can also pass them into the helper.
In my view scripts I'm using the helper like so:
<?=$this->mailingList($this->mailingListForm, $this->mailingListMessages);?>
If neither mailingListForm or mailingListMessages has been set on the view by MailingListController, it will output a new form with no messages.
Any help is greatly appreciated!
Using ajax seems to be an optimal way. View Action Helper is used only for the first load of the mailing form.
Controller
class MailingListController extends Zend_Controller_Action {
public function insertAction() {
$request = $this->getRequest();
$form = new Form_MailingList();
if ($request->isPost()) {
if ($form->isValid($request->getPost())) {
$mailingList = new Model_MailingList();
$emailAddress = $form->getValue('email_address');
$mailingList->addEmailAddress($emailAddress);
$form = $mailingList->getMessages();
}
}
$this->view->form = $form;
}
}
view script insert.phtml
<?php echo $this->form; ?>
Form class
class Form_MailingList extends Zend_Form {
public function init() {
//among other things
$this->setAttrib('id', 'mailing-list-form');
$this->setAction('/mailing-list/insert');
}
}
View Helper
class Zend_View_Helper_MailingList extends Zend_View_Helper_Abstract {
public function mailingList() {
$this->view->headScript()->appendFile('/js/mailing-list.js');
return '<div id="mailing-list-wrap">' . $this->view->action('insert', 'mailing-list') . '</div>';
}
}
JS file mailing-list.js
$(document).ready(function() {
$('#mailing-list-form').submit(function() {
var formAction = $(this).attr('action');
var formData = $(this).serialize();
$.post(formAction, formData, function(data) {
//response going in form's parent container
$(this).parent().html(data);
});
return false;
});
});
I think the way you've done it is pretty close to what I would do. If you set aside the requirement of wanting to display the Zend_Form error messages in the page, then what you do instead is:
The view helper just displays the form (it doesn't need to take the form object or messages as parameters)
The form submits to your other controller as it does now
The mailing list controller redirects (instead of forwarding) back to the return URL on success
The mailing list controller redisplays the form on its own, along with errors on failure
This makes everything much simpler, the only issue is that if there are any validation errors then the user loses their context and gets a plain old page with the form on instead of where they were. You can then address this (either now or at a later date) by changing the form to submit via. Ajax instead, and rendering the errors via. JS. But this would be a fair amount of work.
OK, I've come up with a solution that I feel happier about and solves some of the problems I was facing. Hopefully, this might help someone out who's facing similar issues. The only downside now is that I'm referencing the Model inside the View Helper. Not loose coupling I know but I've seen this done several times before and it's even recommended in the ZF docs as a way to avoid using the 'action' view helper (which will create a new MVC dispatch loop). On the whole, I think the DRYness and encapsulation is worth it, there's probably some other suitable lingo too.
In order to be able to use a redirect back from my MailingListController but maintain the messages from my model and any form validation errors I need to store them in the session. For messages I'd normally use the FlashMessenger action helper, but as getting hold of this in a View Helper is not best practice, it won't handle my form errors and all it's really doing is saving stuff to the session anyway it's unnecessary. I can implement my own session storage in the Model_MailingList, which I can also use for the form errors. I can then repopulate the form with the errors after the redirect and print out any relevant messages. Anyway, here's the code:
Controller:
<?php
class MailingListController extends Zend_Controller_Action {
public function insertAction() {
$request = $this->getRequest();
$returnTo = $request->getParam('return_to');
if(!$request->isPost() || (!isset($returnTo) || empty($returnTo))) {
$this->_redirect('/');
}
$mailingList = new Model_MailingList();
$form = new Form_MailingList();
if($form->isValid($_POST)) {
$emailAddress = $form->getValue('email_address');
$mailingList->addEmailAddress($emailAddress);
}
else {
$mailingList->setFormErrors($form->getMessages());
}
$redirect = rtrim($request->getBaseUrl(), '/') . $returnTo;
$this->_redirect($redirect);
}
}
I've added a method to my Model_MailingList class; setFormErrors($errors) that I pass the error messages from the form if it fails validation. This saves the error array to the session.
I normally use a base model class that has addMessage and getMessages methods. These just access a protected array of messages. In my Model_MailingList I override these methods to store the messages in the session instead. In the addEmailAddress($emailAddress) method I'm already calling addMessage to say whether inserting the email address to the db has been successful.
Model:
<?php
class Model_MailingList extends Thinkjam_Model_DbAbstract {
private $_session;
public function __construct() {
$this->_session = new Zend_Session_Namespace(__CLASS__);
}
public function setFormErrors($errors) {
$this->_session->formErrors = $errors;
}
public function getFormErrors() {
$errors = array();
if(isset($this->_session->formErrors)) {
$errors = $this->_session->formErrors;
unset($this->_session->formErrors);
}
return $errors;
}
// override addMessage and getMessages
protected function addMessage($message) {
if(!isset($this->_session->messages)) {
$this->_session->messages = array();
}
$this->_session->messages[] = $message;
}
public function getMessages() {
if(isset($this->_session->messages)) {
$this->_messages = $this->_session->messages;
unset($this->_session->messages);
}
return $this->_messages;
}
…
public function addEmailAddress($emailAddress) {
...
// I call this if db insert was successful:
$this->addMessage("Thank you. You have been successfully added to the mailing list.")
}
}
I now don't need to pass any params to the view helper as it can query it's state from the Model directly. $this->view->messenger is just another view helper that converts an array to an unordered list.
View Helper:
<?php
class Zend_View_Helper_MailingList extends Zend_View_Helper_Abstract {
private $_mailingList;
public function MailingList() {
$this->_mailingList = new Model_MailingList();
return $this;
}
public function getForm() {
$request = Zend_Controller_Front::getInstance()->getRequest();
$currentPage = '/' . $request->getModuleName() . '/' . $request->getControllerName() . '/' . $request->getActionName();
$form = new Form_MailingList();
$form->setAction('/mailing-list/insert');
$form->setCurrentPage($currentPage);
$form->setErrors($this->_mailingList->getFormErrors());
$html = '<div class="mailingList"><h2>Join Our Mailing List</h2>' . $form;
$html .= $this->view->messenger($this->_mailingList->getMessages());
$html .= '</div>';
return $html;
}
}
Then in the Form_MailingList class I just need to add an additional method to repopulate the error messages. Although getMessages() is a method of Zend_Form there doesn't appear to be any corresponding setMessages(). You can do this on a Zend_Form_Element however, so I've added the following function to the Form_MailingList class:
Form:
<?php
class Form_MailingList extends Thinkjam_Form_Abstract {
...
public function setErrors(array $errors) {
foreach($errors as $key => $value) {
$this->getElement($key)->setErrors($value);
}
}
}
I can now add a signup form on any page of my site using the MailingList view helper:
<?=$this->MailingList()->getForm();?>
I realise a lot of the problems I was facing was down to a very specific set of circumstances, but hopefully this can help some other people out in some way!
Cheers,
Alex
I want to make a class in OOP PHP to validate forms. However, I've having trouble structuring this.
Initially I thought of creating individual functions for each type of validation (check length of submitted data, check whether it's a number or not, etc), then another function to check whether data passed the validation tests and pass errors into an array.
I'm getting stuck though as my code is becoming very long and difficult to manage- I'm pretty new, so how would you approach this problem?
As i was reading through your post, a question came into my mind about what you write:
Why, instead of validating a form, dont you validte your model's objects?
I mean, in an OOP way of looking things your model´s object (or domain objects) are the ones who knows what data is valid or not for each of their attributes.
Not doint that, and pushing that logic into the UI makes your design fragile, UI dependant and harder to maintain. If you add a new attribute to one of your model's object, you'll have to modify the form validator as well.
If you go with Objects Validation, the idea is that an object cannot be created in an invalid state. If you try to modify it with invalid data, an exception will be thrown.
This makes easy to work with forms. The only think you have to do is populate your objects and watch for exceptions thrown in that process.
This is only an idea to get you started and see another way of solving this problem.
Regarding your question about Forms Validation, as the other guys said, it is always better not to reinvent the wheel and go for an existing, proven, validation framework.
However, if you are curious about it, here is one of the many ways you can do it:
Let's go through the things you need: you are talking about a form that needs to be validated with one or more validation functions. Then you talk about a function that tells you whether the form passed the validation or not, and as a result you got the list of errors found during the validation phase.
As you talk about OOP, the way to go is to give each concept or idea of your problem domain (the domain of form validation) entity via a class that represents it that model the behavior they have.
So, it is natural to think about a FormValidator class with a list of ValidationRule instances, where each one colaborates in the validation process. This validation process is done by calling the validate function of the FormValidator. Also, each ValidationRule will give, as result of calling it´s own validate method an instance of the ValidationRuleResult class, that tells whether the validation was successful or not, along with an error message and additional data (if needed) about the validation. Once all the validation rules were evaluated, the validate method of the FormValidator class will return an instance of ValidationResult class, that summarizes all the validation results of the rules evaluated providing the list of errors found.
To get this down to earth, here is the sample model we're talking about:
A sample implementation
Disclaimer: please bear in mind that, as any design, it may contains flaws. The following is intended to help you to solve your problem, not to be a complete solution.
class FormValidator {
private $_validationRules;
function __construct() {
$this->_validationRules = array();
}
// Registers a new validation rule
function addRule($aValidationRule) { $this->validationRules[] = $aValidationRule; }
// Validates $aForm, evaluating each of the $_validationRules defined
function validate($aForm) {
$aValidationResult = new ValidationResult();
foreach($this->_validationRules as $aValidationRule) {
$aValidationRuleResult = $aValidationRule->validate($aForm);
$aValidationResult->addResult($aValidationRuleResult);
}
return $aValidationResult;
}
}
abstract class ValidationRule {
private $_fieldName;
// The form's field name to be validated
function __construct($aFieldName) {
$this->_fieldName = $aFieldName;
}
function fieldName() { return $this->_fieldName; }
// Returns an instance of ValidationResult describing the result of evaluating the ValidationRule in $aForm.
abstract public function validate($aForm);
}
class ValidationResult {
private $_validationRuleResults;
function __construct() {
$this->_validationRuleResults = array();
}
// Registers a validation rule result
function addResult($aValidationRuleResult) {
$this->_validationRuleResults[] = $aValidationRuleResult;
}
// Returns the list of the error messages of the validation rule results that did't passed
function errorsFound() {
$errors = array();
foreach($this->validationRuleResults as $aValidationResult) {
if ($aValidationResult->passed()) continue;
$errors[] = $aValidationResult->errorMessage();
}
return $errors;
}
// Tells whether all the validation rule results passed or not
function validationPassed() {
foreach($this->validationRuleResults as $validationResult) {
if ($validationResult->passed() == false) return false;
}
return true;
}
}
class ValidationRuleResult {
private $_passed, $_error_message;
function __construct($passed) {
$this->_passed = $passed;
$this->_error_message = '';
}
// Tells whether the form passed this validation rule or not
public function passed() { return $this->_passed; }
public function
// The error message should be empty if passed to avoid confusion
public function errorMessage { return $this->passed() ? '' : $this->_error_message; }
public function setErrorMessage($anErrorMessage) { $this->_error_message = $anErrorMessage; }
}
You can create a validation rule this way:
class NotEmptyValidationRule extends ValidationRule {
public function validate($aForm) {
$fieldName = $this->fieldName();
$fieldValue = $aForm[$fieldName];
$passed = !empty($fieldValue);
$result = new ValidationRuleResult($passed);
if (!$passed) {
$result->setErrorMessage("$fieldName cannot be empty");
}
return $result;
}
}
Some things to note:
Im assuming that $aForm is an associative array of field name / value
You can note that if a validation rule passes, the result is not used (as the ValidationResult class works only on those results that didn't pass). Remember that this is a sample only for the purpose of helping you, is not a complete solution.
Usage
$rule = new NotEmptyValidationRule('name');
$validator = new FormValidator();
$validator->addRule($rule);
$aForm = $__POST['myForm'];
$validationResult = $validator->validate($aForm);
if ($validationResult->validationPassed()) {
$errorsFound = $validationResult->errorsFound();
// do something with the $errorMessage
$errorMessage = array_join('<br/>', $errorsFound);
}