# Introduction¶

Note

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## What is the AppBundle?¶

The AppBundle provides a handful of useful functions and workflows, helping you to handle the input and output of any model. The AppBundle does not depend on a concrete model. It handles a model in a very abstract manner.

In a normal web application, we expect to have something like an MVC architecture. We would define our model, controller and our view. If we do it the Symfony way, we also define a form type and add the routing for our controller. The AppBundle provides controller functionality and views, leaving only model/form definition and routing.

The big magic is all in the route. Enhavo (and Sylius) use the routes default section for configuration parameters, allowing you to configure the controllers behaviour and views without having to write them yourself.

This bundle provides you with standard ways of handling your models in a CRUD fashion, allowing you to easily implement your custom models in a CRUD fashion and with a consistent look and feel. And if you have any requirements which the bundle does not provide, we still have a good API to easily add these yourself.

## The default way to handle your data¶

Ok, lets do some simple examples to see what the benefits are for your application. Imagine a library, where we have books. First, we would add our model.

<?php

namespace ProjectBundle\Entity

class Book {
private $author; private$title;
function setAuthor() { /* you know what to do here */ }
//setters, getters
}

If we have a model, we also need the FormType

<?php

namespace ProjectBundle\Form\Type

class BookType extends AbstractType {
public function builder //..
}

Now, you add your controller. Of course our controller need the basic CRUD functions.

<?php

namespace ProjectBundle\Controller

class BookController extends Controller
{
public function createAction() {  /* you know what to do here */ }
public function readAction()   {  /* you know what to do here */ }
public function updateAction() {  /* you know what to do here */ }
public function deleteAction() {  /* you know what to do here */ }
}

After this we write the views.

{% block create %}
{{ form }}
{% endblock %}

{{ form }}
{% endblock %}

{% block update %}
{{ form }}
{% endblock %}

{% block delete %}
{{ form }}
{% endblock %}

And last but not least, we add the routing.

project_book_create:
path: /project/book/create
methods: [GET]
defaults:
_controller: ProjectBundle:Book:create

methods: [GET]
defaults:

project_book_update:
path: /project/book/update
methods: [GET]
defaults:
_controller: ProjectBundle:Book:update

project_book_delete:
path: /project/book/delete
methods: [GET]
defaults:
_controller: ProjectBundle:Book:delete

After this we can add and show the book model.

It’s a common way, and if we have a whole bunch of models, this will be much copy and paste work. So this is where the AppBundle wants to help. Reduce code and define a standard workflow to CRUD your data. This will reduce your code and keep your view clean.

## How we can do this shorter¶

The question is, where can we add a standard workflow to reduce duplicated code, without losing flexibility. The answer is: the controller and the views. They usually are pretty identical for all models. So now we just leave out the part of the view and controller. Instead we add our model to the configuration file and update our routes.

// app/config/config.yml

// ...

sylius_resource:
resources:
project.book:
driver: doctrine/orm
object_manager: default
templates: project:Book
classes:
model: ProjectBundle\Model\Book
controller: ProjectBundle\Controller\BookController
//routing
project_book_create:
path: /project/book/create
methods: [GET]
defaults:
_controller: ProjectBundle:Book:create

methods: [GET]
defaults:

project_book_update:
path: /project/book/update
methods: [GET]
defaults:
_controller: ProjectBundle:Book:update

project_book_delete:
path: /project/book/delete
methods: [GET]
defaults:
_controller: ProjectBundle:Book:delete

Instead of implementing a controller, we just create an empty class and extend AppBundles ResourceController.

<?php
// namespace/uses
class BookController extends ResourceController
{
}

Maybe you ask yourself, why can’t we add the routing dynamically, this is also copy and paste work? Yes, that’s correct. But we need the routing for our configuration to maintain flexibility.

There are some other bundles, like the SonataAdminBundle, that also add default routing. But what about if we, for example, don’t want a delete route? Or we want to use a different template or form? Then we would have to do some work, extending the controller and overwriting functions.

This is what we want to avoid. We want to configure all of these things, and we want to do it in an intuitive place. And in our opinion, this is the route. So for example, if we want to change the form template, we just pass this information to the route definition.

//routing
project_book_create:
path: /project/book/create
methods: [GET]
defaults:
_controller: ProjectBundle:Book:create
_viewer:
form:
template: ProjectBundle:Book:form.html.twig

Of course the route provides much more features and options. This should only give you an idea what this bundle wants to do and where it can help you doing your work. The next chapters will give you a deeper understanding in what you can do with the AppBundle.