Introducing Symfony 2
The Symfony 2 output seemed to me a good reason to finally find the time and see what one of the most popular PHP frameworks in the world is. I described my acquaintance with him in this article. Since this is my first experience with Symfony, I will be glad if you notice any mistakes or shortcomings and tell me about them.
You can download the distribution from the official site . I think it's better to download the standart version that comes with all the additional components. Next, I assume that the archive has been unpacked to the root folder of your web server.
You can check that everything works correctly at this link: http: //localhost/Symfony/web/config.php .
If everything is fine, then you can start, but first you need to comment out one line in the file Symfony / web / app_dev.php
A very strange solution, by default, enable the cache in design mode.
Applications in Symfony 2 have a modular structure, modules are called bundles. Our demo application will be in its own separate bundle. There are a lot of console commands in Symfony to help you get started. There is an appropriate command to generate the structure of a new bundle:
This command must be executed from the console, while in the Symfony / folder. If you work in Linux, then you can assign console privileges to the console file and not write php in front of it. The generator will ask a few simple questions for each of which it has a default answer. Since we are creating our first application, we will agree to all the options. So, by pressing the enter key several times, we get the skeleton of our bundle in the Symfony / src / Demos / BlogBundle folder.
Like most modern frameworks, Symfony adheres to the MVC pattern. We will begin our acquaintance with the implementation of this pattern in Symfony with the last letter, i.e. the controller.
Our small bundle already has one controller, it is called DefaultController and is located in the src / Demos / BlogBundle / Controller folder. If you look inside it, you will see that it has an indexAction action implemented. Now we will see what he is doing. Open the http: //localhost/Symfony/web/app_dev.php/hello/username address in your browser .
You may wonder why this page has such an address, but if you look closely at PHPDoc (these are special comments that start with the characters / **) before the indexAction function, you will probably understand everything. Abstract Routeindicates at which address the action is available and what parameter it has.
In general, you can achieve the same without annotations, but they are used everywhere in Symfony, so it's better to get used to them right away. On the one hand, they are more concise, and on the other hand, they are not very well supported for autocomplete in my favorite IDE .
A special Routing component is responsible for setting how the urls of your application will look, it allows you to configure everything very flexibly. More details can be found in the corresponding section of the documentation . We will briefly consider why our application opens at this address and why we were not required to configure anything for this.
If you didn’t read very carefully what the bundle generator was asking for, then you might well have missed its question of whether to update the routing settings in accordance with the new bundle. If you missed, then you can open the file Symfony \ app \ config \ routing.yml. There you will see the following entry: The first line is the name of the section with the configuration, it corresponds to the name of our bundle. The second line indicates where to import the settings. In this case, they will read all the files from the folder with the controllers, and the next line says that all the necessary settings are described in the action annotations. Well, we have already seen the annotations. And finally, the last line indicates which prefix will be added to all urls from our bundle. By default, all urls are available directly on behalf of the input script. Let's change / to / blog to make it more logical.
Now everything that we will do will be available at http: //localhost/Symfony/web/app_dev.php/blog .
Now let's move on to the next step - working with the database. I will use Doctrine, although no one obliges to do this, instead of the doctrine, you can use any way you want to work with the database. However, the doctrine is well integrated with symfony and it is a pleasure to work with it.
First, configure the connection to the database. Open the app / config / parameters.ini file and describe your settings. By the way, I wonder why all the default settings are in yml, and this one is in the ini-file. If you specified a non-existing database in the settings, then run the following command:
php app / console doctrine: database: create
and the doctrine itself will create it.
The doctrine is a full-fledged ORM , but it is based on a different principle than ActiveRecord, with which many now clearly associate this concept. The doctrine implements the Data Mapper template, which is described in detail here .
First we need to describe the essence with which we will work. This will be the Post class with the properties we need. Create the src / Demos / BlogBundle / Entity folder. In it, create a Post.php file and fill it with the following code: The class itself is not connected to the database in any way, but the annotations contain a description of which of the class’s properties will be table columns and what type they will be. I think from the annotations, everything is quite obvious. All properties are declared protected, so you need to create getters and setters to access them. To do this, use the appropriate doctrine command:
Now look at the Post.php file, the appropriate methods should appear in it. We have a description of the model, according to it we need to create the appropriate table in the database. To do this, follow:
If everything went smoothly, then the post table should appear in your database. Let's move on to working directly with objects. In the DefaultController class, create a new action with this code: And at the top of the file you need to add the import of the necessary namespaces: Now if you open the address http: //localhost/Symfony/web/app_dev.php/blog/create , then you should get id created record. Now create an action to display existing records. To do this, we need an action with a parameter that will take the record id.
Now you can view the recording by clicking on the link http: //localhost/Symfony/web/app_dev.php/blog/show/1 . This concludes the doctrine, details in the documentation .
It's time to move on to the final part of our introduction to Symfony. At the last step, we didn’t mix the work logic with the record output in showAction very well. View will help us to get rid of this drawback (in Russian, “view” sounds somehow not very good, so I will call it a view;).
Symfony uses Twig as the template engine, which is probably the best PHP template engine I've worked with. Like any other component of the symphony, you can replace it with what you like best.
As you recall, the indexAction action has a special Template () annotation that says it has a template.
The array that is returned from the action is passed to the view, the array keys will be the names of the variables that will be available there.
Let's change the show action. It is necessary to add the corresponding annotation and instead of returning the Response object, return the array in which the record will be viewed. Here's what happened: Agree, it's much better. Now, in the src / Demos / BlogBundle / Resources / views / Default folder, create a show.html.twig file into which we transfer the html code that we had the action. Twig syntax is different from php so you have to change something. The final version, see the source. You can learn more about twig syntax in its documentation .
Perhaps I will dwell on this for now. I hope it will be interesting to someone else besides me. It was a bit tricky to get started with Symfony in the beginning, but still interesting. All sources are available on github .
1. Installation and setup
You can download the distribution from the official site . I think it's better to download the standart version that comes with all the additional components. Next, I assume that the archive has been unpacked to the root folder of your web server.
You can check that everything works correctly at this link: http: //localhost/Symfony/web/config.php .
If everything is fine, then you can start, but first you need to comment out one line in the file Symfony / web / app_dev.php
$kernel->loadClassCache();A very strange solution, by default, enable the cache in design mode.
2. Creating a new application
Applications in Symfony 2 have a modular structure, modules are called bundles. Our demo application will be in its own separate bundle. There are a lot of console commands in Symfony to help you get started. There is an appropriate command to generate the structure of a new bundle:
php app/console generate:bundle --namespace=Demos/BlogBundleThis command must be executed from the console, while in the Symfony / folder. If you work in Linux, then you can assign console privileges to the console file and not write php in front of it. The generator will ask a few simple questions for each of which it has a default answer. Since we are creating our first application, we will agree to all the options. So, by pressing the enter key several times, we get the skeleton of our bundle in the Symfony / src / Demos / BlogBundle folder.
3. The controller and the basics of routing
Like most modern frameworks, Symfony adheres to the MVC pattern. We will begin our acquaintance with the implementation of this pattern in Symfony with the last letter, i.e. the controller.
Our small bundle already has one controller, it is called DefaultController and is located in the src / Demos / BlogBundle / Controller folder. If you look inside it, you will see that it has an indexAction action implemented. Now we will see what he is doing. Open the http: //localhost/Symfony/web/app_dev.php/hello/username address in your browser .
You may wonder why this page has such an address, but if you look closely at PHPDoc (these are special comments that start with the characters / **) before the indexAction function, you will probably understand everything. Abstract Routeindicates at which address the action is available and what parameter it has.
In general, you can achieve the same without annotations, but they are used everywhere in Symfony, so it's better to get used to them right away. On the one hand, they are more concise, and on the other hand, they are not very well supported for autocomplete in my favorite IDE .
A special Routing component is responsible for setting how the urls of your application will look, it allows you to configure everything very flexibly. More details can be found in the corresponding section of the documentation . We will briefly consider why our application opens at this address and why we were not required to configure anything for this.
If you didn’t read very carefully what the bundle generator was asking for, then you might well have missed its question of whether to update the routing settings in accordance with the new bundle. If you missed, then you can open the file Symfony \ app \ config \ routing.yml. There you will see the following entry: The first line is the name of the section with the configuration, it corresponds to the name of our bundle. The second line indicates where to import the settings. In this case, they will read all the files from the folder with the controllers, and the next line says that all the necessary settings are described in the action annotations. Well, we have already seen the annotations. And finally, the last line indicates which prefix will be added to all urls from our bundle. By default, all urls are available directly on behalf of the input script. Let's change / to / blog to make it more logical.
DemosBlogBundle:
resource: "@DemosBlogBundle/Controller/"
type: annotation
prefix: /
Now everything that we will do will be available at http: //localhost/Symfony/web/app_dev.php/blog .
4. Working with Doctrine: Creating a Model
Now let's move on to the next step - working with the database. I will use Doctrine, although no one obliges to do this, instead of the doctrine, you can use any way you want to work with the database. However, the doctrine is well integrated with symfony and it is a pleasure to work with it.
First, configure the connection to the database. Open the app / config / parameters.ini file and describe your settings. By the way, I wonder why all the default settings are in yml, and this one is in the ini-file. If you specified a non-existing database in the settings, then run the following command:
php app / console doctrine: database: create
and the doctrine itself will create it.
The doctrine is a full-fledged ORM , but it is based on a different principle than ActiveRecord, with which many now clearly associate this concept. The doctrine implements the Data Mapper template, which is described in detail here .
First we need to describe the essence with which we will work. This will be the Post class with the properties we need. Create the src / Demos / BlogBundle / Entity folder. In it, create a Post.php file and fill it with the following code: The class itself is not connected to the database in any way, but the annotations contain a description of which of the class’s properties will be table columns and what type they will be. I think from the annotations, everything is quite obvious. All properties are declared protected, so you need to create getters and setters to access them. To do this, use the appropriate doctrine command:
namespace Demos\BlogBundle\Entity;
use Doctrine\ORM\Mapping as ORM;
/**
* @ORM\Entity
* @ORM\Table(name="post")
*/
class Post {
/**
* @ORM\Id
* @ORM\Column(type="integer")
* @ORM\GeneratedValue(strategy="AUTO")
*/
protected $id;
/**
* @ORM\Column(type="string", length=255)
*/
protected $title;
/**
* @ORM\Column(type="text")
*/
protected $body;
/**
* @ORM\Column(type="datetime")
*/
protected $created_date;
/**
* @ORM\Column(type="datetime")
*/
protected $updated_date;
}php app/console doctrine:generate:entities Demos/BlogBundle/Entity/PostNow look at the Post.php file, the appropriate methods should appear in it. We have a description of the model, according to it we need to create the appropriate table in the database. To do this, follow:
php app/console doctrine:schema:update --forceIf everything went smoothly, then the post table should appear in your database. Let's move on to working directly with objects. In the DefaultController class, create a new action with this code: And at the top of the file you need to add the import of the necessary namespaces: Now if you open the address http: //localhost/Symfony/web/app_dev.php/blog/create , then you should get id created record. Now create an action to display existing records. To do this, we need an action with a parameter that will take the record id.
/**
* @Route("/create")
*/
public function createAction() {
$post = new Post();
$post->setTitle('Demo Blog');
$post->setBody('Hello Symfony 2');
$post->setCreatedDate(new \DateTime("now"));
$post->setUpdatedDate(new \DateTime('now'));
$em = $this->getDoctrine()->getEntityManager();
$em->persist($post);
$em->flush();
return new Response('Created product id ' . $post->getId());
}
use Demos\BlogBundle\Entity\Post;
use Symfony\Component\HttpFoundation\Response;
/**
* @Route("/show/{id}")
*/
public function showAction($id)
{
$post = $this->getDoctrine()->getRepository('DemosBlogBundle:Post')->find($id);
if (!$post) {
throw $this->createNotFoundException('Страница не найдена!');
}
$html = <<
{$post->getTitle()}
{$post->getBody()}
Запись создана {$post->getCreatedDate()->format("Y-m-d H:i:s")}
HTML;
return new Response($html);
}
?>
Now you can view the recording by clicking on the link http: //localhost/Symfony/web/app_dev.php/blog/show/1 . This concludes the doctrine, details in the documentation .
5. Twig: the first templates
It's time to move on to the final part of our introduction to Symfony. At the last step, we didn’t mix the work logic with the record output in showAction very well. View will help us to get rid of this drawback (in Russian, “view” sounds somehow not very good, so I will call it a view;).
Symfony uses Twig as the template engine, which is probably the best PHP template engine I've worked with. Like any other component of the symphony, you can replace it with what you like best.
As you recall, the indexAction action has a special Template () annotation that says it has a template.
return array('name' => $name);The array that is returned from the action is passed to the view, the array keys will be the names of the variables that will be available there.
Let's change the show action. It is necessary to add the corresponding annotation and instead of returning the Response object, return the array in which the record will be viewed. Here's what happened: Agree, it's much better. Now, in the src / Demos / BlogBundle / Resources / views / Default folder, create a show.html.twig file into which we transfer the html code that we had the action. Twig syntax is different from php so you have to change something. The final version, see the source. You can learn more about twig syntax in its documentation .
/**
* @Route("/show/{id}")
* @Template()
*/
public function showAction($id)
{
$post = $this->getDoctrine()->getRepository('DemosBlogBundle:Post')->find($id);
if (!$post) {
throw $this->createNotFoundException('Страница не найдена!');
}
return array('post' => $post);
}6. Conclusion
Perhaps I will dwell on this for now. I hope it will be interesting to someone else besides me. It was a bit tricky to get started with Symfony in the beginning, but still interesting. All sources are available on github .