From 3bf17fb1423283d79a81b6ec3ca6134566b28475 Mon Sep 17 00:00:00 2001
From: Joël Cox <joel@joelcox.nl>
Date: Sun, 9 Oct 2011 19:20:12 +0200
Subject: Initial conversion of the HTML to RST using pandoc.

---
 user_guide_src/source/tutorial/news_section.rst | 213 ++++++++++++++++++++++++
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 create mode 100644 user_guide_src/source/tutorial/news_section.rst

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+Tutorial − News section
+=======================
+
+In the last section, we went over some basic concepts of the framework
+by writing a class that includes static pages. We cleaned up the URI by
+adding custom routing rules. Now it's time to introduce dynamic content
+and start using a database.
+
+Setting up your model
+---------------------
+
+Instead of writing database operations right in the controller, queries
+should be placed in a model, so they can easily be reused later. Models
+are the place where you retrieve, insert, and update information in your
+database or other data stores. They represent your data.
+
+Open up the application/models directory and create a new file called
+news\_model.php and add the following code. Make sure you've configured
+your database properly as described
+`here <../database/configuration.html>`_.
+
+::
+
+    <?php
+    class News_model extends CI_Model {
+
+        public function __construct()
+        {
+            $this->load->database();
+        }
+    }
+
+This code looks similar to the controller code that was used earlier. It
+creates a new model by extending CI\_Model and loads the database
+library. This will make the database class available through the
+$this->db object.
+
+Before querying the database, a database schema has to be created.
+Connect to your database and run the SQL command below. Also add some
+seed records.
+
+::
+
+    CREATE TABLE news (
+        id int(11) NOT NULL AUTO_INCREMENT,
+        title varchar(128) NOT NULL,
+        slug varchar(128) NOT NULL,
+        text text NOT NULL,
+        PRIMARY KEY (id),
+        KEY slug (slug)
+    );
+
+Now that the database and a model have been set up, you'll need a method
+to get all of our posts from our database. To do this, the database
+abstraction layer that is included with CodeIgniter — `Active
+Record <../database/active_record.html>`_ — is used. This makes it
+possible to write your 'queries' once and make them work on `all
+supported database systems <../general/requirements.html>`_. Add the
+following code to your model.
+
+::
+
+    public function get_news($slug = FALSE)
+    {
+        if ($slug === FALSE)
+        {
+            $query = $this->db->get('news');
+            return $query->result_array();
+        }
+        
+        $query = $this->db->get_where('news', array('slug' => $slug));
+        return $query->row_array();
+    }
+
+With this code you can perform two different queries. You can get all
+news records, or get a news item by its `slug <#>`_. You might have
+noticed that the $slug variable wasn't sanitized before running the
+query; Active Record does this for you.
+
+Display the news
+----------------
+
+Now that the queries are written, the model should be tied to the views
+that are going to display the news items to the user. This could be done
+in our pages controller created earlier, but for the sake of clarity, a
+new "news" controller is defined. Create the new controller at
+application/controllers/news.php.
+
+::
+
+    <?php
+    class News extends CI_Controller {
+
+        public function __construct()
+        {
+            parent::__construct();
+            $this->load->model('news_model');
+        }
+
+        public function index()
+        {
+            $data['news'] = $this->news_model->get_news();
+        }
+
+        public function view($slug)
+        {
+            $data['news'] = $this->news_model->get_news($slug);
+        }
+    }
+
+Looking at the code, you may see some similarity with the files we
+created earlier. First, the "\_\_construct" method: it calls the
+constructor of its parent class (CI\_Controller) and loads the model, so
+it can be used in all other methods in this controller.
+
+Next, there are two methods to view all news items and one for a
+specific news item. You can see that the $slug variable is passed to the
+model's method in the second method. The model is using this slug to
+identify the news item to be returned.
+
+Now the data is retrieved by the controller through our model, but
+nothing is displayed yet. The next thing to do is passing this data to
+the views.
+
+::
+
+    public function index()
+    {
+        $data['news'] = $this->news_model->get_news();
+        $data['title'] = 'News archive';
+
+        $this->load->view('templates/header', $data);
+        $this->load->view('news/index', $data);
+        $this->load->view('templates/footer');
+    }
+
+The code above gets all news records from the model and assigns it to a
+variable. The value for the title is also assigned to the $data['title']
+element and all data is passed to the views. You now need to create a
+view to render the news items. Create application/views/news/index.php
+and add the next piece of code.
+
+::
+
+    <?php foreach ($news as $news_item): ?>
+
+        <h2><?php echo $news_item['title'] ?></h2>
+        <div id="main">
+            <?php echo $news_item['text'] ?>
+        </div>
+        <p><a href="news/<?php echo $news_item['slug'] ?>">View article</a></p>
+
+    <?php endforeach ?>
+
+Here, each news item is looped and displayed to the user. You can see we
+wrote our template in PHP mixed with HTML. If you prefer to use a
+template language, you can use CodeIgniter's `Template
+Parser <../libraries/parser.html>`_ class or a third party parser.
+
+The news overview page is now done, but a page to display individual
+news items is still absent. The model created earlier is made in such
+way that it can easily be used for this functionality. You only need to
+add some code to the controller and create a new view. Go back to the
+news controller and add the following lines to the file.
+
+::
+
+    public function view($slug)
+    {
+        $data['news_item'] = $this->news_model->get_news($slug);
+
+        if (empty($data['news_item']))
+        {
+            show_404();
+        }
+
+        $data['title'] = $data['news_item']['title'];
+
+        $this->load->view('templates/header', $data);
+        $this->load->view('news/view', $data);
+        $this->load->view('templates/footer');
+    }
+
+Instead of calling the get\_news() method without a parameter, the $slug
+variable is passed, so it will return the specific news item. The only
+things left to do is create the corresponding view at
+application/views/news/view.php. Put the following code in this file.
+
+::
+
+    <?php
+    echo '<h2>'.$news_item['title'].'</h2>';
+    echo $news_item['text'];
+
+Routing
+-------
+
+Because of the wildcard routing rule created earlier, you need need an
+extra route to view the controller that you just made. Modify your
+routing file (application/config/routes.php) so it looks as follows.
+This makes sure the requests reaches the news controller instead of
+going directly to the pages controller. The first line routes URI's with
+a slug to the view method in the news controller.
+
+::
+
+    $route['news/(:any)'] = 'news/view/$1';
+    $route['news'] = 'news';
+    $route['(:any)'] = 'pages/view/$1';
+    $route['default_controller'] = 'pages/view';
+
+Point your browser to your document root, followed by index.php/news and
+watch your news page.
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