Building a Simple API using Opulence PHP

This tutorial will show you how to code a simple JSON API using Opulence PHP. We will install Opulence’s skeleton project using composer, then create a ‘user’ database entity, and finally we will match CRUD (Create, Read, Update, Delete) to POST, GET, PUT, and DELETE.

Prerequisites: PHP7, Composer, MySQL.

Installing

Create an Opulence project with the following command:

composer create-project opulence/project SimpleApi --prefer-dist 

The default Opulence app name is Project. Using apex, rename it to SimpleApi.

cd SimpleApi
php apex app:rename Project SimpleApi

This command will output:

JSON Config

According to the documentation if a client does not request JSON then HTML will be returned. This is “the right way to do it” but for the sake of this API we always want to return JSON. We can do this by adding the following code to config/http/views.php:

if (!isset($_SERVER['CONTENT_TYPE'])) {
    $_SERVER['CONTENT_TYPE'] = 'application/json';
}

We also want to disable the default Session and Csrf middlewares because REST clients do not (always) work with cookies. Open config/http/middleware.php and comment out:

return [
    CheckMaintenanceMode::class,
//    Session::class,
//    CheckCsrfToken::class
];

Database Config

Out of the box PostgreSQL is the default database driver. To use MySQL change line ~5 in src/SimpleApi/Application/Bootstrappers/Databases/SqlBootstrapper.php from PostgreSQL to:

use Opulence\Databases\Adapters\Pdo\MySql\Driver;

Manually create a MySQL database named simpleapi and modify config/environment/.env.app.php accordingly.

Environment::setVar('DB_HOST', 'localhost');
Environment::setVar('DB_USER', 'root');
Environment::setVar('DB_PASSWORD', 'root');
Environment::setVar('DB_NAME', 'simpleapi');
Environment::setVar('DB_PORT', 3306);

Database Entity

Create a user table with the following columns: [ id (primary), email (unique), firstname (string), lastname (string), age (integer, optional) , country (2 character string) ]

CREATE TABLE `user` (
  `id` int NOT NULL AUTO_INCREMENT PRIMARY KEY,
  `email` varchar(255) NOT NULL UNIQUE,
  `firstname` varchar(255) NOT NULL,
  `lastname` varchar(255) NOT NULL,
  `age` int,
  `country` char(2) NOT NULL
);

Using apex, create a matching entity class named User.

php apex make:entity User

 

Note: These commands create stubs / empty templates. You must finish the code yourself!

 

Open the newly created src/SimpleApi/User.php and finish the mutator methods so that the properties match the database table. Implement JsonSerializable too.

<?php 
namespace SimpleApi; 

use Opulence\Orm\IEntity; 

class User implements IEntity, \JsonSerializable { 

    /** @var int */ 
    private $id;
 
    /** @var string */ 
    private $email; 

    /** @var string */ 
    private $firstname; 

    /** @var string */ 
    private $lastname; 

    /** @var int|null */ 
    private $age; 

    /** @var string */ 
    private $country; 

    public function getId(): int 
    { 
        return (int)$this->id;
    }

    public function setId($id): self
    {
        $this->id = $id;

        return $this;
    }

    public function getEmail(): string
    {
        return $this->email;
    }

    public function setEmail($email): self
    {
        $this->email = $email;

        return $this;
    }

    public function getFirstname(): string
    {
        return $this->firstname;
    }

    public function setFirstname($firstname): self
    {
        $this->firstname = $firstname;

        return $this;
    }

    public function getLastname(): string
    {
        return $this->lastname;
    }

    public function setLastname($lastname): self
    {
        $this->lastname = $lastname;

        return $this;
    }

    /**
     * @return int|null
     */
    public function getAge()
    {
        return $this->age;
    }

    public function setAge($age): self
    {
        $this->age = $age;

        return $this;
    }

    public function getCountry(): string
    {
        return $this->country;
    }

    public function setCountry($country): self
    {
        $this->country = $country;

        return $this;
    }

    public function jsonSerialize() : array
    {
        return [
            'id' => (int)$this->getId(),
            'email' => $this->getEmail(),
            'firstname' => $this->getFirstname(),
            'lastname' => $this->getLastname(),
            'age' => is_null($this->getAge()) ? null : (int)$this->getAge(),
            'country' => $this->getCountry(),
        ];
    }
}

Open src/SimpleApi/Application/Bootstrappers/Orm/OrmBootstrapper.php and register an ID generator for \SimpleApi\User

private function registerIdGenerators(IIdGeneratorRegistry $idGeneratorRegistry)
{
    // Register your Id generators for classes that will be managed by the unit of work
    $idGeneratorRegistry->registerIdGenerator(
        \SimpleApi\User::class,
        new \Opulence\Orm\Ids\Generators\IntSequenceIdGenerator('user_id_seq')
    );
}

Database Mapper

Using apex, create a SQL data mapper named User. When prompted pick SQL data mapper and use \SimpleApi\User as the entity.

php apex make:datamapper User

This command will output:

Open the newly created src/SimpleApi/Infrastructure/Orm/User.php and finish the stubs.

<?php 

namespace SimpleApi\Infrastructure\Orm; 

use Opulence\Orm\DataMappers\SqlDataMapper; 
use Opulence\Orm\OrmException; 

class User extends SqlDataMapper { 

   /** 
    * Adds an entity to the database 
    *
    * @param \SimpleApi\User $user The entity to add 
    * @throws OrmException Thrown if the entity couldn't be added 
    */ 
    public function add($user) 
    { 
        $statement = $this->writeConnection->prepare(
            'INSERT INTO user (email, firstname, lastname, age, country)
             VALUES (:email, :firstname, :lastname, :age, :country)'
        );
        $statement->bindValues([
            'email' => $user->getEmail(),
            'firstname' => $user->getFirstname(),
            'lastname' => $user->getLastname(),
            'age' => $user->getAge(),
            'country' => $user->getCountry(),
        ]);
        $statement->execute();
    }

    /**
     * Deletes an entity
     *
     * @param \SimpleApi\User $user The entity to delete
     * @throws OrmException Thrown if the entity couldn't be deleted
     */
    public function delete($user)
    {
        $statement = $this->writeConnection->prepare('DELETE FROM user WHERE id = :id');
        $statement->bindValues([
            'id' => [$user->getId(), \PDO::PARAM_INT]
        ]);
        $statement->execute();
    }

    /**
     * Gets all the entities
     *
     * @return \SimpleApi\User[] The list of all the entities
     */
    public function getAll() : array
    {
        $sql = 'SELECT * FROM user';

        return $this->read($sql, [], self::VALUE_TYPE_ARRAY);
    }

    /**
     * Gets the entity with the input Id
     *
     * @param int|string $id The Id of the entity we're searching for
     * @return \SimpleApi\User The entity with the input Id
     * @throws OrmException Thrown if there was no entity with the input Id
     */
    public function getById($id): \SimpleApi\User
    {
        $sql = 'SELECT * FROM user WHERE id = :id';
        $parameters = [
            'id' => [$id, \PDO::PARAM_INT]
        ];

        return $this->read($sql, $parameters, self::VALUE_TYPE_ENTITY, true);
    }

    /**
     * Saves any changes made to an entity
     *
     * @param \SimpleApi\User $user The entity to save
     * @throws OrmException Thrown if the entity couldn't be saved
     */
    public function update($user)
    {
        $statement = $this->writeConnection->prepare(
            'UPDATE user SET email = :email, firstname = :firstname, lastname = :lastname,
             age = :age, country = :country
             WHERE id = :id'
        );
        $statement->bindValues([
            'email' => $user->getEmail(),
            'firstname' => $user->getFirstname(),
            'lastname' => $user->getLastname(),
            'age' => $user->getAge(),
            'country' => $user->getCountry(),
            'id' => [$user->getId(), \PDO::PARAM_INT]
        ]);
        $statement->execute();
    }

    /**
     * Loads an entity from a hash of data
     *
     * @param array $hash The hash of data to load the entity from
     * @return \SimpleApi\User The entity
     */
    protected function loadEntity(array $hash): \SimpleApi\User
    {
        $entity = new \SimpleApi\User();

        $entity->setId($hash['id']);
        $entity->setEmail($hash['email']);
        $entity->setFirstname($hash['firstname']);
        $entity->setLastname($hash['lastname']);
        $entity->setAge($hash['age']);
        $entity->setCountry($hash['country']);

        return $entity;
    }
}

Controller Creation

Using apex, create a Controller named User. When prompted pick REST controller.

php apex make:controller User

This command will output:

Open the newly created src/SimpleApi/Application/Http/Controllers/User.php and finish the stubs. Type-hint any objects your controller needs in the controller’s constructor. Create a generic repository object for \SimpleApi\User.

<?php 

namespace SimpleApi\Application\Http\Controllers; 

use Opulence\Http\HttpException; 
use Opulence\Http\Responses\JsonResponse; 
use Opulence\Http\Responses\Response; 
use Opulence\Orm\OrmException; 
use Opulence\Orm\Repositories\Repository; 
use Opulence\Orm\IUnitOfWork; 
use Opulence\Routing\Controller; 

class User extends Controller { 

    /** @var \Opulence\Orm\UnitOfWork */ 
    protected $unitOfWork; 

    /** @var Repository */ 
    protected $repo; 

    public function __construct(\SimpleApi\Infrastructure\Orm\User $dataMapper, IUnitOfWork $unitOfWork) 
    { 
        $this->unitOfWork = $unitOfWork;

        $this->repo = new Repository(
            \SimpleApi\User::class,
            $dataMapper,
            $this->unitOfWork
        );
    }

    /**
     * Creates a entity
     *
     * @return Response The response
     */
    public function create() : Response
    {
        $json = $this->request->getJsonBody();

        $user = new \SimpleApi\User();

        $user
            ->setEmail($json['email'])
            ->setFirstname($json['firstname'])
            ->setLastname($json['lastname'])
            ->setCountry($json['country']);

        if (isset($json['age'])) {
            $user->setAge($json['age']);
        }

        $this->repo->add($user);
        $this->unitOfWork->commit();

        return new JsonResponse($user);
    }

    /**
     * Deletes an entity
     *
     * @param mixed $id The Id of the entity
     * @return Response The response
     */
    public function delete($id) : Response
    {
        $user = $this->repo->getById($id);
        $this->repo->delete($user);
        $this->unitOfWork->commit();

        return new JsonResponse($user, 204);
    }

    /**
     * Shows an entity
     *
     * @param mixed $id The Id of the entity
     * @return Response The response
     * @throws HttpException
     */
    public function show($id) : Response
    {
        try {
            $user = $this->repo->getById($id);
        } catch (OrmException $e) {
            throw new HttpException(404);
        }

        return new JsonResponse($user);
    }

    /**
     * Shows all the entities
     *
     * @return Response The response
     */
    public function showAll() : Response
    {
        $user = $this->repo->getAll();

        return new JsonResponse($user);
    }

    /**
     * Updates an entity
     *
     * @param mixed $id The Id of the entity
     * @return Response The response
     */
    public function update($id) : Response
    {
        $json = $this->request->getJsonBody();

        /** @var \SimpleApi\User $user */
        $user = $this->repo->getById($id);

        if (isset($json['email'])) {
            $user->setEmail($json['email']);
        }
        if (isset($json['firstname'])) {
            $user->setFirstname($json['firstname']);
        }
        if (isset($json['lastname'])) {
            $user->setLastname($json['lastname']);
        }
        if (isset($json['country'])) {
            $user->setCountry($json['country']);
        }
        if (isset($json['age'])) {
            $user->setAge($json['age']);
        }

        $this->unitOfWork->commit();

        return new JsonResponse($user);
    }
}

Open config/http/routes.php and configure CRUD routes to use the controller class.

$router->group(['controllerNamespace' => 'SimpleApi\Application\Http\Controllers'], function (Router $router) {
    $router->group(['path' => '/user'], function (Router $router) {
        $router->get('', 'User@showAll');
        $router->post('', 'User@create');
    });
    $router->group(['path' => '/user/:id'], function (Router $router) {
        $router->get('', 'User@show');
        $router->put('', 'User@update');
        $router->delete('', 'User@delete');
    });
});

Barring any typos you should now have a simple API. To run Opulence locally, use the following command:

php apex app:runlocally

Use a REST client to POST the following JSON to the API:

 

POST: http://localhost/user

 

{
    "email": "foo@dev.null",
    "firstname": "Joe",
    "lastname": "Smith",
    "age": 999,
    "country": "JP"
}

Then try:

 

GET: http://localhost/user
GET: http://localhost/user/1
PUT: http://localhost/user/1
DELETE: http://localhost/user/1 

 

Got ideas on how to improve validation, error handling, security, or any other Opulence PHP tips? Post in the comments below.

Install PHP7 and Composer on Windows 10

PHP7 is a general purpose scripting language well suited for web development. Composer is the defacto package manager for PHP7. This tutorial will show you how to install PHP7 and Composer on Windows 10 for use in a command prompt.

A common misconception is that you need a web server like IIS, Apache, or Nginx to get started with PHP7 development. In fact, PHP7 has its own built in web server that you can invoke at the command prompt. Modern PHP frameworks such as Opulence, Symfony, Cake, Laravel, WordPress, and many more support this.

Installing PHP7

Download the latest PHP7 (non-thread safe version) zip file from http://windows.php.net/

Extract the contents of the zip file into C:\PHP7

Copy C:\PHP7\php.ini-development to C:\PHP7\php.ini

Open the newly copied C:\PHP7\php.ini in a text editor.

Scroll down to “Directory in which the loadable extensions (modules) reside.” and uncomment: extension_dir = “ext”

Notepad++ is great.

Scroll down to the extensions section and uncomment the extensions you want to use.

Note: The syntax used in previous PHP versions (‘extension=’php_*.dll’) may be deprecated in a future PHP major version.

Tweak other settings as needed.

Note: Don’t forget to keep your php.ini file in a safe place when you upgrade in the future!

Add C:\PHP7 to the Windows 10 system path environment variable.

Windows 10 has finally improved this interface, yay!

In a command prompt test that the installation is successful by typing php -v

ConEmu is great.

Installing Composer

On my computer I’ve created a C:\Users\dac\bin directory where I keep miscellaneous executables. This directory is in my user path.

Use a search engine to find a tutorial and do something similar. Optionally install composer in the C:\PHP7 directory you just created as it’s already in your path.

To get composer.phar, drop to a command prompt, cd into your target directory, and run:

php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
php composer-setup.php
php -r "unlink('composer-setup.php');"

(Important! Click here for a more secure and up-to-date install snippet.)

Next, create a new composer.bat file alongside the composer.phar file so that Windows 10 can execute it more easily. (Source)

echo @php "%~dp0composer.phar" %*>composer.bat

Test that it’s working by typing composer -V

ConEmu is still great.

Autocomplete a Silex Project in PHPStorm

The problem with Silex, and Pimple in general, is that when you do:

$app = new \Pimple\Container();
$app['Foo'] = function () { return new \Acme\Foo(); };
$app['Bar'] = function () { return new \Acme\Bar(); };

PHPStorm has no way of knowing what’s going on in, or how to auto-complete, $app.

I’ve gotten around this in the past by creating an “Inception Proxy” alongside a .phpstorm.meta.php configuration but for a new Silex project I’ve inherited this is not possible.

Pro-tip: If your IDE doesn’t know what’s going on then neither will the poor jerks who inherit your code.

Looking for a solution to this I discovered the PHPStorm Silex Plugin. It’s a bit wonky but it does the job. (sometimes the IDE doesn’t recognize $app and I don’t know why yet.)

For the Silex Plugin to work it requires a manually created configuration file in the project root named “pimple.json”. This file more or less duplicates the functionality of .phpstorm.meta.php but I digress… Pimple.json can be automatically generated using Pimple Dumper.

The format of “pimple.json” looks like:

[
    {
        "name": "routes",
        "type": "class",
        "value": "Symfony\\Component\\Routing\\RouteCollection"
    },
    {
        "name": "request.http_port",
        "type": "int",
        "value": 80
    },
    {
        "name": "charset",
        "type": "string",
        "value": "UTF-8"
    }
]

Once that file is in place, and you jiggle the IDE/Plugin, auto-complete comes alive! Horray for sanity.

PHP Configuration Files Rant

Let’s start with a joke. This GitHub repository:

“It’s funny ’cause it’s true” -Homer Simpson

Text configuration files (XML, Yaml, JSON, INI, …) work when the configuration is read once, the software persists in memory, and the application doesn’t exit until the user is done.

This is not what PHP does best. Sure PHP also reads the configuration file “once” but the fundamental difference is that PHP starts and exits dozens, maybe hundreds, of times for a single user using a single application.

The metaphorical equivalent would be relaunching World Of Warcraft every time time a user clicks on something.

I know some of you are thinking “Well that’s dumb. I wrote a game in PHP and the webpage isn’t reloading every time the user clicks…” but break that down: you wrote PHP which renders something the user is experiencing in a web-browser (C++) that may or may not be making Ajaxy calls back to the server (JavaScript) and PHP’s role in this solution is always to start-up, process data, return data, then exit.

For PHP to be the right tool for the right job, it has to be fast. Fast for developers to develop in *and* also fast for end users. (Hooray for PHP7!)

Some clever devs get around configuration performance problems by adding extra steps such as transpiling text into pure PHP before deploying, but do these complicated solutions really serve the PHP developer and the underlying philosophy of how we write code? When it comes to PHP there is a nuanced difference between “performance” and “fast.”

Let’s talk about JSON.

JSON, a “text only” and “language independent” data-interchange format, is currently the cool kid on the block, but from the perspective of JavaScript?

var json = { "this": "is", "valid": "javascript" };

Wow. Talk about language independence. No reprocessing!

The equivalent in PHP:

$php = [ 'this' => 'is', 'valid' => 'php' ];

Tada! No overhead of having to validate, process, and convert to PHP. Is it uglier? Debatable.

To be clear: XML, Yaml, JSON, and friends are fine as documents or as data to be processed by PHP.  This is totally normal and sometimes even useful. 😉 Barring that, any reasonable PHP developer must conclude that configuration files cannot be a bottleneck.  Not a bottleneck for speed of delivering shippable code, nor a bottleneck for acceptable performance. When choosing anything other than native PHP for configuration you are making a trade-off. Is the trade off worth it? The answer is always no. 1

But the secretary needs to be able to edit the app config live on the server and PHP is too hard for him!

No.

But caching! But Transpiling!

No.

But I like coding parsers!

Cool! Use your powers for docs and data, not PHP configs.

But I secretly want to be a JavaScript, Python, Ruby, C#, Java or anything but a PHP developer!

Uhhh, OK?

[1] Unless you are storing your PHP configs in Apache or Nginx as ENV variables. Then to you madam or sir, I bow down.

WP Memcached Object Cache Leaks Memory?

While working on Pressbooks, a multi-site WordPress based web application, I noticed that some of our customers were getting blank pages in the admin section. Specifically, customers with a lot of Sites (or Books as they are known in Pressbooks).

Checking the error logs I saw that these customers were running out of memory.

PHP Fatal error:  Allowed memory size of 268435456 bytes exhausted (tried to allocate 292913 bytes) in /path/to/object-cache.php on line 212.

First, to temporarily stop the out-of-memory problem so I could profile I added the following to wp-config.php:

define( 'WP_MAX_MEMORY_LIMIT', '512M' );

Next, using Blackfire.IO I was able to determine the following:

Before
Before (285 MB)

That is, when a customer was looking at their dashboard, PHP was consuming 285MB of memory. Most of it the Memcached Object Cache plugin.

That’s weird. I’m using the latest version of the plugin, the plugin is developed by core developers, and no one has reported this before? Or so I thought! Browsing the plugin SVN I see the following change committed to trunk:

Changeset 626248

There’s a few more fixes in there as well. After installing the TRUNK version of this plugin Blackfire.IO displayed:

After
After (12.2MB)

That’s a 273MB improvement!

It took me days to figure out this problem. It would have saved me a lot of time had I seen the new code first.

Bonus info:

  • The code in TRUNK has at least 2 bugs. (…just load the file in PHPStorm and the errors will be underlined in red)
  • Redis Object Cache gives better results.

For now, this is good enough.