Kohana Tutorial: Part 2

Here is the 2^nd part of 3 part series of Kohana tutorial. First part of this tutorial can be found here as Kohana Tutorial: For the beginners. Same as before it is going to be 10+/- steps.

This part is going to cover

Template Controller in Kohana
Kohana ORM (relation & validation)

Why Template Controller?

Its tedious and repetitive task to create and manage all the view files with header, footer, menu… etc all the time. So it could be better, if we had a common template to handle this kind of stuffs. Kohana have Template Controller to rescue you.

Lets create a template

We want that, our website will have common pattern with header, menu, css etc. We need to create a simple template file like as below.

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
	"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
	<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
	<title>Kohana Blog</title>
	<!-- this is how, you you can add a css file -->
	<?php echo HTML::style("public/css/template.css"); ?>
	<!-- this is how, you you can add a javascript file -->
	<?php echo HTML::script("public/js/jquery-1.6.4.js"); ?>
</head>

<body>
<div id="wrapper">
	<!-- Header for the site -->
	<div id="header"><h1>Kohana Blog</h1></div>
	
	<!-- Menu for the site -->
	<div id="navlist">
		<ul>
			<li><?php echo HTML::anchor("", "Home"); ?></li>
			<li><?php echo HTML::anchor("article", "Articles"); ?></li>
			<li><?php echo HTML::anchor("article/edit", "New Article"); ?></li>
		</ul>
	</div>
	
	<!-- here we load all content -->
	<div id="content">
		<?php echo $content; ?>
	</div>
	
	<!-- no footer added -->
</div>
</body>
</html>

Working with template controller

Now we need to say our controller that, from now on you are going to handle the template yourself. To do this we need to change our article controller. We can do it in following way.

Extend Controller_Article from Controller_Template instead of Controller
Set the template for your controller as $template = “template”, since our template file is template.php in view folder.
For all actions populate the $template as highlighted below at line 12. Do it for all other methods where required.

// extends the Controller_Template
class Controller_Article extends Controller_Template {

	public $template = 'template';
	...
	public function action_index() {
		$articles = ORM::factory('article')->find_all(); // loads all article object from table

		$view = new View('article/index'); // load 'article/index.php' view file
		$view->set("articles", $articles); // set "articles" object to view

		$this->template->set('content', $view); // renders a view as a response
	}
	...
}

It should be fun and easy to do this. Now hit the url: http://localhost/kohana-blog/index.php/article and see the magic. We can see a nice look of our Kohana Blog.

Working with ORM

Already you got some idea on how ORM works if you have practiced Part 1. Now its time to do something few more with ORM. Lets play with ORM relation & validation in Kohana.

Create comment model

How about adding comments to all these articles. Use the following script to create a comments table.

CREATE TABLE IF NOT EXISTS `comments` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `article_id` int(10) NOT NULL,
  `comment` varchar(45) NOT NULL,
  `time` datetime NOT NULL,
  `name` varchar(45) NOT NULL,
  `email` varchar(45) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `fk_comments_article` (`article_id`)
);

And below we see the Comment Model.

<?php defined('SYSPATH') or die('No direct script access.');
class Model_Comment extends ORM {

}

Now add relation to models

An article can have multiple comment. That means one-to-many relation. This is how we can do it using Kohana ORM.

<?php defined('SYSPATH') or die('No direct script access.');

class Model_Article extends ORM {

	 // contains many relations
 	protected $_has_many = array(
 		// an article has many comments
 		'comments' => array(
			'model'		=> 'comment',
			'foreign_key'	=> 'article_id',
		),
	);

}

Now something like $article->comments will allow us to get all comments for an article

And a comment can be related to only one article. So it is many-to-one relation. Below shows, how we can do it using Kohana ORM.

<?php defined('SYSPATH') or die('No direct script access.');

class Model_Comment extends ORM {

 	// contains many to one relation mainly
 	protected $_belongs_to = array (
		// a comment is related to only one article
 		'article' => array (
			'model'		=> 'article',
			'foreign_key'	=> 'article_id'
		)
	);
}

Now something like $comment->article will allow us to get article related to a comment

We wont be able to see any big difference on how ORM is working here, but later part of the discussion should give some hints.

Some improvement

Before going further, lets show a single article first. It should be simple as follows.

Create an action to load the article

class Controller_Article extends Controller_Template {
	...
	public function action_view() {
		$article_id = $this->request->param('id');
		$article = ORM::factory('article', $article_id);
		$view = new View('article/single');
		$view->set("article", $article);
		
		$this->template->set('content', $view);
	}
	...
}

Create a view file to show the article

<?php defined('SYSPATH') or die('No direct script access.'); ?>

<div>
	<h2><?php echo $article->title; ?></h2>
	<pre><?php echo $article->content; ?></pre>
	<?php echo HTML::anchor("article/edit/".$article->id, "Edit"); ?>
	<?php echo HTML::anchor("article/delete/".$article->id, "Delete"); ?>
</div>

Now it is possible to view an article in a single page. We can try opening a url like: http://localhost/kohana-blog/index.php/article/view/1

Add comments to an article

Now we will add comments to an article. Create an edit form & a Controller_Comment to save the comment for a certain article. These are the changes we need to do.

Create the comment edit form

<?php defined('SYSPATH') or die('No direct script access.'); ?>

<h3>Add your comment</h3>

<?php echo Form::open('comment/post/'); ?>
	<?php echo Form::label("name", "Name"); ?>
	<br />
	<?php echo Form::input("name", $comment->name); ?>
	<br />
	<br />
	<?php echo Form::label("email", "Email"); ?>
	<br />
	<?php echo Form::input("email", $comment->email); ?>
	<br />
	<br />
	<?php echo Form::label("comment", "Comment"); ?>
	<br />
	<?php echo Form::textarea("comment", $comment->comment); ?>
	<br />
	<br />
	<?php echo Form::hidden("article_id", $article->pk()); ?>
	<?php echo Form::submit("submit", "Submit"); ?>
<?php echo Form::close(); ?>

Load the form from article view page

<?php defined('SYSPATH') or die('No direct script access.'); ?>

<div>
	<h2><?php echo $article->title; ?></h2>
	<pre><?php echo $article->content; ?></pre>
	<?php echo HTML::anchor("article/edit/".$article->id, "Edit"); ?>
	<?php echo HTML::anchor("article/delete/".$article->id, "Delete"); ?>
</div>

<!-- this practice should be preferable, instead of cluttering a single article page with everything -->
<?php echo View::factory('comment/edit', array('comment'=>new Model_Comment(),'article'=>$article )); ?>

Create the action to save the comment in Comment Controller

<?php defined('SYSPATH') or die('No direct script access.');

class Controller_Comment extends Controller {
	
	public function action_post() {
		$comment = new Model_Comment();
		$comment->values($this->request->post());
		$comment->save();
		
		$this->request->redirect("index.php/article/view/".$comment->article_id);
	}

}

Now try making some comments to one of the article. We have not shown the comments yet, so you should check them in your database

Show article comments

At first, we create a view file to show a single comment.

<?php defined('SYSPATH') or die('No direct script access.'); ?>

<div class="comment">
	<span><?php echo $comment->name; ?></span>
	<pre><?php echo $comment->comment; ?></pre>
</div>

Article’s view page can show all these comments as shown below. $article->comments should be interesting. It refers to comments related to an article.

...
<div id="comments" style="margin: 10px 0px 10px 0px">
	<?php foreach ($article->comments->find_all() as $comment) : ?>
		<!-- showing a single comment -->
		<?php echo View::factory('comment/single', array('comment'=>$comment)); ?>
	<?php endforeach; ?>
</div>

<!-- this practice should be preferable, instead of cluttering a single article page with everything -->
<?php echo View::factory('comment/edit', array('comment'=>new Model_Comment(),'article'=>$article )); ?>

Here $article->comments should be easily understood. I am not gonna explain it

So far, so good. Now we hit the url: http://localhost/blog/index.php/article/view/1 and see all those comments.

Working with ORM validation

How about trying with validation in Kohana ORM. It will be nice if we could validate model data each time before saving to database. Lets see, how we can do it with Kohana ORM.

But don’t be confused, I am just focusing on validating a model object. Using Kohana Validation it is possible to validate any other things also.

<?php defined('SYSPATH') or die('No direct script access.');

class Model_Article extends ORM {
	
	// contains many relations
	protected $_has_many = array(
		// an article has many comments
		'comments' => array(
			'model'			=> 'comment',
			'foreign_key'	=> 'article_id',
		),
	);
	
	/**
	 * Rule definitions for validation
	 *
	 * @return array
	 */
	public function rules()	{
		return array (
			'title' => array (
				array('not_empty'),
			),
			'content' => array (		// property name to validate
				array('not_empty'),		// validation type
				array(
					'min_length',		// validation type
					array(':value', 10)	// validation parameters
				),
			),
		);
	}
	
}

Now try creating some article with invalid data, and you will see ORM_Validation_Exception. We need to show these error messages. So we need to catch this exception in while saving the article and show these error messages in article edit form. Here we go…

class Controller_Article extends Controller_Template {

	...

	// save the article
	public function action_post() {
		$article_id = $this->request->param('id');
		$article = new Model_Article($article_id);
		$article->values($this->request->post()); // populate $article object from $_POST array
		$errors = array();
		
		try {
			$article->save(); // saves article to database
			$this->request->redirect(self::INDEX_PAGE);
		} catch (ORM_Validation_Exception $ex) {
			$errors = $ex->errors('validation');
		}
		
		$view = new View('article/edit');
		$view->set("article", $article);
		$view->set('errors', $errors);
		
		$this->template->set('content', $view);
	}
	
}

Update the form to show error message

<?php defined('SYSPATH') or die('No direct script access.'); ?>

<h1><?php echo ($article->id? "Edit" : "New"); ?> article</h1>

<?php $errors = isset($errors) ? $errors : array(); ?>

<?php echo Form::open('article/post/'.$article->id); ?>
	<?php echo Form::label("title", "Title"); ?>
	<br />
	<?php echo Form::input("title", $article->title); ?>
	<span class="error"><?php echo Arr::get($errors, 'title');?></span>
	<br />
	<br />
	<?php echo Form::label("content", "Content"); ?>
	<br />
	<?php echo Form::textarea("content", $article->content); ?>
	<span class="error"><?php echo Arr::get($errors, 'content');?></span>
	<br />
	<br />
	<?php echo Form::submit("submit", "Submit"); ?>
<?php echo Form::close(); ?>

Now try creating an article with invalid data here: http://localhost/kohana-blog/index.php/article/edit. Check if the error messages are shown correctly

Bonus! Show label in validation

It should be all. But wait, still one more hints. It should be nice if we could see “title” instead of “title” or “Content” instead of “content” in error message. We can do it by following way. Create a function label which will return label for all the fields of a model.

class Model_Article extends ORM {
	...
	public function labels() {
		return array(
			'title'         => 'Title',
			'content'       => 'Content',
		);
	}

}

Now we will see nice error message with their label with it.

This is all for today

. I have tried to give some basic idea on…

Template Controller on Kohana
Kohana ORM: Working with relation
Kohana ORM: Working with validation
Organize view files, if you have noticed how I have organized view files

Downloads: https://bitbucket.org/kowsercse/kohana-blog
Part 1: Kohana Tutorial: For the beginners
More on Kohana: http://kerkness.ca/kowiki/doku.php

33 Responses to Kohana Tutorial: Part 2

Jorge November 7, 2011

Hi there

I’ve just started learning kohana 3 and this is by far the best and most up to date tutorial out there.

I’ve also found a book from Packt Publishing by Jason D. Straughan, Kohana 3.0 Beginner’s Guide. Even although the book is only 4 months old the code is outdated, which is very discourage for beginners like me.

Thanks a lot for sharing your ideas. Hope to see more from you.

Greetings from Spain

Reply
Bilash Saha November 8, 2011

Hi,

Great tutorial !!!

Hope to see more.

Carry on.

Reply
- fg October 17, 2012
  
  lllllllllllllll
  
  Reply
Sinan E. November 23, 2011

I loved your post. Learned so many things.
Thanks you very much.

Reply
- Kowser November 24, 2011
  
  Glad, that you liked it so much.
  
  Reply
James January 8, 2012

Hi thanks for the great tutorial I have one issue with the first part .
I get error message “kohana_Exception [0]: the content property does not exist in the Model_Article class”.
Can you ple
ase help me figure out what’s wrong? Thank you so much.

Reply
- Jouanne Jimmy January 27, 2013
  
  Hi James,
  I got this error and it’s our fault because we don’t put the good thing in the good file.
  Here is the solution :
  
  // application/classes/Model/Article.php
  class Model_Article extends ORM {
  // contains many relations
  protected $_has_many = array(
  // an article has many comments
  ‘comments’ => array(
  ‘model’ => ‘comment’,
  ‘foreign_key’ => ‘article_id’,
  ),
  );
  }
  
  and the second model comment
  
  // application/classes/Model/Comment.php
  class Model_Comment extends ORM {
  // contains many to one relation mainly
  protected $_belongs_to = array (
  // a comment is related to only one article
  ‘article’ => array (
  ‘model’ => ‘article’,
  ‘foreign_key’ => ‘article_id’
  )
  );
  }
  
  It’s two different code which not contains on the same file.
  
  Reply
Abdullah Al Mamun January 24, 2012

Thanks a lot.
Really, a brilliant series for kohana newbies.
Hope, on next part you will focus on authentication.

Reply
Jeremy March 10, 2012

When is part 3 due?

Reply
S van Boxel March 14, 2012

Still waiting for part 3… I can use it.

Reply
Lynks March 21, 2012

Great portion of knowledge – all I know about KOHANA, is thanks you
I hope you will publish 3rd part of your series.

Greetings from Poland

Reply
T.G April 7, 2012

Very useful article!

wrong filename: kohana-blog/application/views/article/edit.php this is comment/edit.php

Reply
- Kowser April 7, 2012
  
  Thanks for pointing the issue. And glad to know it was helpful for you.
  
  Reply
venkatraja April 18, 2012

how to set id,class in input format in kohana

Reply
Daka April 27, 2012

What about database injection xxs attack etc.
Does ORM really clean it up, so we don’t need to do that?
like if we using database we will say Database::instance()->escape($string)
is it by ORM different?

Reply
Robert May 4, 2012

Hi,
Just writing to encourage you to do some more tutorials. I´m also new to kohana and find tutorials like the ones you have written which are task-based much more valuable than formal definitions and abstract explainations.

I hope you are planning to write many more soon,

yours,

Rob

Reply
Robert May 7, 2012

Hi,

I´m having a problem connecting to the database. I dapated database.sql for my username and password, but when I go to http://MyDomain/kohana/article/ I just get this…
“Database_Exception [ 2 ]: mysql_connect(): Access denied for user ‘www-data’@'localhost’ (using password: NO)”

can you tell me what´s going wrong?

thanks,

Rob

Reply
- mark May 14, 2012
  
  hi rob,
  
  check your username and database name in config/database.php the error is showing the script can’t connect to the database with that login information
  
  Reply
reddy May 16, 2012

this tutorial is very helpful and hope you can continue writing the series with full kohana tutorial.

Reply
an0nemous June 1, 2012

Great tutorial, thanks!! However, I do have one question, why not just re-use the edit action in action_post to display the error. Seems more like code repetition to me. Could you not simply pass the errors to that function? Thanks.

Reply
fabiyi adeolu August 19, 2012

I should say tttttthankssssss so much for the tutorials you have really blessed my life. You are lifted.Greetings from Nigeria

Reply
Jason McCarrell August 23, 2012

Great article.

FYI you have an error in the factory portion of the comments. You can’t set the variables through the factory. I don’t know why, but according to the user guide you need to simply chain set and use that.

The variable simply does not end up being defined.

You should definitely do part 3. Well written .

Reply
Dinesh October 8, 2012

This is a very nice ORM tutorial, Thanks a lot, Please continue with more tutorials..

I have some doubts : If we are adding a same article title, it is updating to table. I want to check whether the article is already existing in table. I have added as in Model class:-

public function rules() {
return array (
‘title’ => array (
array(‘not_empty’),

array(‘min_length’, array(‘:value’, 4)),
array(‘max_length’, array(‘:value’, 48)),
array(array($this, ‘title_notavailable’)),
),

public function title_notavailable($title)
{

return !(bool) DB::select(‘title’)
->from($this->_table_name)
->where(‘title’, ‘=’, $title)
->execute();

}

It is not validating properly!..

Please suggest a good solution

Reply
- arumdev April 21, 2013
  
  I’m having trouble getting the templates working, would appreciate some help.
  
  it all works fine with (from the first part of your tutorial:
  
  class Controller_Article extends Controller {
  const INDEX_PAGE = “article”; // just give the name of Controller..
  public $template = ‘template’; // initiate the template variable
  
  public function action_index() {
  $articles = ORM::factory(‘article’)->find_all(); // loads all article object from table
  
  $view = new View(‘article/index’);
  $view->set(“articles”, $articles); // set “articles” object to view
  
  $this->response->body($view); // render the view as response
  }
  
  but when I make the changes:
  
  class Controller_Article extends Controller_Template { // make sure extends correct class
  const INDEX_PAGE = “article”; // just give the name of Controller..
  public $template = ‘template’; // initiate the template variable
  
  public function action_index() {
  $articles = ORM::factory(‘article’)->find_all(); // loads all article object from table
  
  $view = new View(‘article/index’);
  $view->set(“articles”, $articles); // set “articles” object to view
  
  $this->template->set(‘content’, $view); // renders a view as a response
  }
  
  I get the following error (in fact I can remove all the code inside the “class Controller_Article extends Controller” and I get the exact same error):
  
  View_Exception [ 0 ]: The requested view template could not be found
  SYSPATH/classes/Kohana/View.php [ 257 ]
  252 */
  253 public function set_filename($file)
  254 {
  255 if (($path = Kohana::find_file(‘views’, $file)) === FALSE)
  256 {
  257 throw new View_Exception(‘The requested view :file could not be found’, array(
  258 ‘:file’ => $file,
  259 ));
  260 }
  261
  262 // Store the file path locally
  SYSPATH/classes/Kohana/View.php [ 137 ] » Kohana_View->set_filename(arguments)
  SYSPATH/classes/Kohana/View.php [ 30 ] » Kohana_View->__construct(arguments)
  SYSPATH/classes/Kohana/Controller/Template.php [ 33 ] » Kohana_View::factory(arguments)
  SYSPATH/classes/Kohana/Controller.php [ 69 ] » Kohana_Controller_Template->before()
  {PHP internal call} » Kohana_Controller->execute()
  SYSPATH/classes/Kohana/Request/Client/Internal.php [ 97 ] » ReflectionMethod->invoke(arguments)
  SYSPATH/classes/Kohana/Request/Client.php [ 114 ] » Kohana_Request_Client_Internal->execute_request(arguments)
  SYSPATH/classes/Kohana/Request.php [ 990 ] » Kohana_Request_Client->execute(arguments)
  DOCROOT/index.php [ 118 ] » Kohana_Request->execute()
  
  my application directory looks like this:
  
  bootstrap.php
  cache/
  classes/
  Controller/
  article.php
  Welcome.php
  Model/
  article.php
  config
  i18n
  logs
  messages
  views/
  article/
  edit.php
  index.php
  template.php
  
  any help would be so appreciated as I’m still very new to kohana and MVC and even OOP in general.
  
  Reply
  - arumdev April 21, 2013
    
    Sorry please ignore my question, posted in the wrong place and also I fixed it, template file was one level too far down… duh
    
    Reply
John December 25, 2012

As an old man learning something new, I find your tutorial very interesting. My only problem is that in testing, all was okay until the program was complete and I receive the following error:

]
28
29 **** error ****
30

If you could kindly point me in the correct direction, I would greatly appreciate it.

Reply
John December 28, 2012

referenced problem solved.

Reply
Mans abbas January 14, 2013

Even i tried to fix all code errors but still didn’t work my form page, when click “New article” Link its shown this error,
ErrorException [ Notice ]: Undefined variable: content

why this error..?? i think any small code errors,

thanks

Reply
- wuwu February 18, 2013
  
  add this :
  “$this->template->set(‘content’, $view);”
  at the end of method action_new()
  
  Reply
mahamood March 18, 2013

hi,
good job. tk u. there are so many frameworks available. i hope kohana is really optimum.

Reply
Admiral April 11, 2013

This is by far the best HOWTO in Kohana I’ve seen. Thank you for giving a piece of your brain.

Greetings from the Davao City, Philippines

Reply
arumdev April 21, 2013

Ok, really good tutorial once again. A few problems I came across:

‘redirect(self::INDEX_PAGE);’ does not work in 3.3, change to ‘HTTP::redirect(self::INDEX_PAGE);’ (remove single quotes of course).

Also, the second-to-last step “Update the form to show error message” left the problem where if the new article page is loaded fresh the errors aren’t defined:

‘ErrorException [ Notice ]: Undefined variable: errors’ etc

so instead of

”
”

I added:

”
”

hope that helps anyone getting the same errors. It’s kinda obvious but took my a while to pinpoint the problem.

Reply
- arumdev April 21, 2013
  
  ok your blog didn’t like the code. you just need to add a check to see if $errors is set:
  
  if(isset($errors)){echo Arr::get($errors, ‘title’);}
  
  Reply