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Using CakePHP ORM in your app

CakePHP ORM in your app

We all know that CakePHP is a Full Stack framework, but you may not know that you can pick some of the components and use it in your app when you need. The ORM is not the only one available - you could also have filesystem, validation, utility, core, collection, database, cache, event, form, log, datasource, console and i18n. In this article, we are going to show how to use the ORM component in your slim framework app. You can find the component at: https://github.com/cakephp/?q=read&type=&language=

 

Why should we use the componentes

You may be asking why to use as component instead of using the framework as it is, and one of the reasons would be that you already have an application, perhaps using slim framework, and now you need to retrieve data from database. This would be a good moment to use a lib to help you, and here is where cakephp/orm comes in handy.

With the componentes you can now solve things with your knowledge in CakePHP, even when your application was not built with CakePHP.

 

Setting up cakephp/orm in a slim application

The code used in this article can be found at: https://github.com/CakeDC/slim-cakephp4-packages

We could use the package in any PHP application, but for this article we are going to use a slim application skeleton https://github.com/slimphp/Slim-Skeleton. In this app we’re going to change the routes /users and /users/[id] to fetch data from database instead of in-memory data.

 

Install the package with composer

We are going to install the version 4.0 of the ORM package:

 

composer require cakephp/orm:~4.0

 

Update config

The app uses the file app/settings.php to set up the main configs, so we need to add a config for database and set cakephp’s App.namespace config.

First: add this line after the use declaration. Don’t worry about this config now. We’re setting this to avoid error with PHP 7.4.

 

Configure::write('App.namespace', 'App');

 

Then add your database config key inside settings array - in this case we’re using mysql database from a docker service:

 

            'database' => [

                'className' => \Cake\Database\Connection::class,

                'driver' => \Cake\Database\Driver\Mysql::class,

                'database' => 'my_db',

                'username' => 'root',

                'password' => 'secret',

                'host' => 'mysql',

            ]

 

See https://github.com/CakeDC/slim-cakephp4-packages/blob/main/app/settings.php

 

Add TableLocator to app dependencies

The app uses the file app/dependencies.php to configure the container of dependencies, and this is a good place for us to define TableLocator as dependency since we normally would use it

In my places. Let’s add this inside $containerBuilder->addDefinitions:

 

\Cake\ORM\Locator\TableLocator::class => function(ContainerInterface $c) {

            $settings = $c->get('settings');

            \Cake\Datasource\ConnectionManager::setConfig('default', $settings['database']);

 

            return new \Cake\ORM\Locator\TableLocator();

 }

 

See https://github.com/CakeDC/slim-cakephp4-packages/blob/main/app/dependencies.php

 

 

This service gets the settings we defined before,sets the configuration to CakePHP, and returns an instance of TableLocator.

We could use this service in any route action with: 

 

$locator  = $this->get(\Cake\ORM\Locator\TableLocator::class);

$users = $locator->get('Users')->find()->all()->toArray();

 

But for this app it will make sense to use the TableLocator in a custom persistence class.

 

Using the ORM to fetch data

Now, we are finally going to replace the current way of retrieving data to be able to use CakePHP OR. Since our idea is to have a minimum impact in the app, the best way for this app is to replace the current UserRepository. Keep in mind that you could use the following steps with any other class you have.

 

Create a new persistence class DatabaseUserRepository:

Create the class at src/Infrastructure/Persistence/User/DatabaseUserRepository.php

Define a constructor method with tableLocator parameter

 

    public function __construct(\Cake\ORM\Locator\TableLocator $tableLocator)

    {

              $this->tableLocator = $tableLocator;

    }

        

Now we can use the tableLocator to fetch data:

 

      $this->tableLocator->get('Users')->find()->all();

      $this->tableLocator->get('Users')->get(10);

      ////

 

To make the app work correctly, we need  to add the required method findAll  and findUserOfId

 

See: https://github.com/CakeDC/slim-cakephp4-packages/blob/main/src/Infrastructure/Persistence/User/DatabaseUserRepository.php

    

Now that the repository persistence class was created, we need to connect using dependency injection. Update the UserRepository::class entry in repositories with:

 

UserRepository::class => \DI\autowire(\App\Infrastructure\Persistence\User\DatabaseUserRepository::class),

 

https://github.com/CakeDC/slim-cakephp4-packages/blob/main/app/repositories.php

 

That’s it! Now we can access /users and see the users stored in our database.

 

I hope you’ve found this information to be helpful! Let us know!

For more information check out: https://github.com/cakephp/orm.

Latest articles

A CakePHP Docker Development Environment

We sponsor a monthly CakePHP training session (register here https://training.cakephp.org ) where we cover different topics about the framework. One of our sessions, the "Getting Started with CakePHP 4" is aimed to help developers starting a new project quickly and following the best practices.   Our previous "recommended" quick setting for a CakePHP development environment was using a vagrant box. See details here:  https://www.cakedc.com/jorge_gonzalez/2018/01/17/using-a-vagrant-box-as-quick-environment-for-the-getting-started-with-cakephp-training-session. However, we've switched internally to use docker as our primary development environment and also we started using docker in our training sessions.   Here's a quick overview of a simple docker based development environment for CakePHP.  

1. Create a new CakePHP project skeleton using 

composer create-project cakephp/app myproject   A new folder "myproject" will be created with a CakePHP project skeleton inside. Go to this new directory and proceed.  

2. Create a new "docker-compose.yaml" file with the following contents

version: '3' services:   mysql8:     image: mysql:8     restart: always     container_name: mysql     environment:         MYSQL_ROOT_PASSWORD: root         MYSQL_DATABASE: my_app         MYSQL_USER: my_app         MYSQL_PASSWORD: secret     volumes:       - ./:/application     ports:       - '9306:3306'     cakephp:     image: webdevops/php-apache:8.0     container_name: cakephp     working_dir: /application/webroot     volumes:       - ./:/application     environment:       - WEB_DOCUMENT_ROOT=/application/webroot       - DATABASE_URL=mysql://my_app:secret@mysql/my_app     ports:       - "8099:80"
 

3. Run "docker-compose up"

You'll create 2 containers named mysql and cakephp -  check the docker-compose configuration to see default database and users created in the mysql container, and the same environment params passed to the cakephp container via DATABASE_URL to allow the cakephp container to connect with the mysql database.   NOTE: the ports exposed are 9306 for mysql and 8099 for cakephp webserver. You can list them using docker-compose ps.  

4. Access your database and cakephp shell

  • To access the database you can use the command:
mysql --port 9306 -umy_app -psecret my_app   To restore a database dump for example, you can use the command: curl -L https://raw.githubusercontent.com/CakeDC/cakephp4-getting-started-session/master/my_app.sql |mysql --port 9306 -umy_app -psecret my_app   You can also configure any database tool to access the database in: localhost:9306  
  • To access the cakephp environment and shell you can use the command:
docker exec -it --user application cakephp bash   You'll go to the webroot folder, so in order to run the cake shell you'll need to: cd .. bin/cake 
  Now you have a working environment to play with the training session contents.   In this previous article, we covered another approach to setting up a local docker environment: https://www.cakedc.com/rochamarcelo/2020/07/20/a-quick-cakephp-local-environment-with-docker    We hope to see you in our next training session! https://training.cakephp.org   

Updating Model Layer

One reason to migrate from CakePHP 2.x to newer versions, is the very powerful ORM system that was introduced in CakePHP 3.x.  

Improved ORM Objects

The CakePHP model layer in CakePHP 3.x uses the Data Mapper pattern. Model classes in CakePHP 3.x ORM are split into two separate objects. Entity represents a single row in the database and it is responsible for keeping record state. Table class provides access to a collection of database records and describe associations, and provides api to work with a database. One notable change is afterFind callback removal. In CakePHP 3.x, it is possible to use Entity level getters to provide calculated fields on entity level.  

Association Upgrade 

In CakePHP 2.x associations are defined as arrays properties like this:     public $belongsTo = [         'Profile' => [             'className' => 'Profile',             'foreignKey' => 'profile_id',         ]     ];   In CakePHP 3.x and 4.x associations are declared in the initialize method. This gives much more flexibility in association configuration.     public function initialize(): void     {         $this->belongsTo('Profile', [                 'className' => 'Profile',                 'foreignKey' => 'profile_id',         ]);              }   Or using setters syntax, it could be done this way: public function initialize(): void     {         $this->belongsTo('Profile')         ->setForeignKey('profile_id')     }  

Behavior Upgrade

In CakePHP 2.x, behaviors are initialized as arrays properties:     public $actsAs = [         'Sluggable' => [             'label' => 'name',         ],     ];   In CakePHP 3.x and 4.x,  behaviors are configured in the initialize method. This gives much more flexibility in configuration, as in params it's possible to pass anonymous functions.     public function initialize(): void     {         $this->addBehavior('Sluggable', [             'label' => 'name',         ]);              }  

Validation Upgrade

In CakePHP 2.x, behaviors are  initialized as arrays properties:     public $validation = [         'title' => [             'notBlank' => [                 'rule' => ['notBlank'],                 'allowEmpty' => false,                 'required' => true,                 'message' => 'Title is required'             ],         ],     ];   In CakePHP 3.x and 4.x, validation is defined in validationDefault method which builds validation rules.     public function validationDefault(Validator $validator): Validator     {         $validator             ->scalar('title')             ->requirePresence('title', 'create')             ->notEmptyString('title');           return $validator;     }   Additionally, CakePHP introduced the buildRules method, which is where  described foreign keys constraints, uniqueness, or business level rules.     public function buildRules(RulesChecker $rules): RulesChecker     {         $rules->add($rules->existsIn(['user_id'], 'Users'));         $rules->add($rules->isUnique(['username'], __('username should be unique')));                            return $rules;     }  

Finder Methods

In CakePHP 2.x, the custom finder method is called twice - before and after fetching data from the database, which is defined by the $state parameter. Parameter $query contains current query state, and in $results passed data returned from database.     protected function _findIndex($state, $query, $results = array()) {         if ($state == 'before') {             $query['contain'] = ['User'];         } else {             // ...         }     }       In CakePHP 3.x, custom finder method accepts query object and some options passed from client code and returns an updated query. This allows for combining multiple finder methods in the same call, and has better grained finder logic.     public function findIndex(Query $query, array $options): Query     {         return $query->contain(['Users']);     }   The afterFind method could be implemented with the Query::formatResults method, which accepts an anonymous function to map each collection item.

Why Database Compression?

Nowadays people are not concerned about how large their database is in terms of MB. Storage is cheap. Even getting cheap SSD storage is not a big deal.    However, this is true if we are talking about hundreds of MB or even several GB, but sometimes we get into a situation where we have massive amounts of data (i.e Several tables with lots of longtext columns). At this point it becomes a concern because we need to increase the hard disk size, and find ourselves checking to see  if the hard disk is full several times per day or week, etc.   Now, if you have faced a situation like this before, it's time to talk about database compression. Compression is a technique, developed theoretically back in the 1940s but actually implemented in the 1970s. For this post we will focus on MySQL compression, which is performed using the open-source ZLib library. This library implements the LZ77 dictionary-based compression algorithm.   Before going into MySQL compression details, lets name some of the main DBMS and their compression techniques:

  • MySQL: ZLib (LZ77) [1]
  • Oracle: Oracle Advanced Compression (Proprietary)[2]
  • Postgres: PGLZ or LZ4 (if added this option at compilation level) [3]
  • DB2: Fixed-length compression or Huffman in some systems [4]
  So, now that we know this useless information, lets learn how to implement this in MySQL.   Firstly, you need to know that you CAN'T enable compression if:
  • Your table lives into `system` tablespace, or
  • Your tablespace was created with the option `innodb_file_per_table` disabled.
  It is important to test if the compression is the best solution for you.  If you have a table with a lot of small columns, you will probably end up with a larger-size table after "compressing" because of the headers and compression information. Compression is always great when you have longtext columns which can be heavily compressed.   Then, to enable compression for a table, you just need to include the following option when your table is created, or execute it as part of an alter statement: ROW_FORMAT=COMPRESSED These are the basics but you may find more useful information in MySQL manual.   You can also take a look at Percona which implements a Column level compression. This is interesting if you have a table with a lot of small fields and one large column, or if you have to optimize your database as much as possible. [6]   Finally, just say that even that storage is cheaper than ever, the amount of information has increased as well and we are now using and processing an incredible amount of data... so it looks like compression will always be a requirement.   I hope you find this information useful and please let me know if you have any questions or suggestions below in the comments section.

  [1]:https://dev.mysql.com/doc/internals/en/zlib-directory.html  [2]:https://www.oracle.com/technetwork/database/options/compression/advanced-compression-wp-12c-1896128.pdf  [3]:https://www.postgresql.org/docs/devel/runtime-config-client.html  [4]:https://www.ibm.com/docs/en/db2-for-zos/12?topic=performance-compressing-your-data  [6]:https://www.percona.com/doc/percona-server/8.0/flexibility/compressed_columns.html

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