diff options
Diffstat (limited to 'user_guide_src/source/tutorial/news_section.rst')
| -rw-r--r-- | user_guide_src/source/tutorial/news_section.rst | 218 |
1 files changed, 0 insertions, 218 deletions
diff --git a/user_guide_src/source/tutorial/news_section.rst b/user_guide_src/source/tutorial/news_section.rst deleted file mode 100644 index 286d620dc..000000000 --- a/user_guide_src/source/tutorial/news_section.rst +++ /dev/null @@ -1,218 +0,0 @@ -############ -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 :doc:`here <../database/configuration>`. - -:: - - <?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 (MySQL). -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 — -:doc:`Query Builder <../database/query_builder>` — is used. This makes it -possible to write your 'queries' once and make them work on :doc:`all -supported database systems <../general/requirements>`. 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; :doc:`Query Builder <../database/query_builder>` 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'); - $this->load->helper('url_helper'); - } - - public function index() - { - $data['news'] = $this->news_model->get_news(); - } - - public function view($slug = NULL) - { - $data['news_item'] = $this->news_model->get_news($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. -It also loads a collection of :doc:`URL Helper <../helpers/url_helper>` -functions, because we'll use one of them in a view later. - -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. - -:: - - <h2><?php echo $title; ?></h2> - - <?php foreach ($news as $news_item): ?> - - <h3><?php echo $news_item['title']; ?></h3> - <div class="main"> - <?php echo $news_item['text']; ?> - </div> - <p><a href="<?php echo site_url('news/'.$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 :doc:`Template -Parser <../libraries/parser>` 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 update ``view()`` with the following: - -:: - - public function view($slug = NULL) - { - $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 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. |