Interface with DB Facade in Laravel - php

Question

First, I apologize if this is a stupid question. I recently read an article about repository design pattern and I have a problem when making interface implementation for Laravel Query Builder (Illuminate\Support\Facades\DB).
DatabaseService.php
use Modules\Core\Interfaces\IDatabase;
use \DB;
class DatabaseService implements IDatabase
{
protected $db;
public function __construct(DB $db)
{
$this->db = $db;
}
public function select($str)
{
$this->db::select($str);
return $this->db;
}
public function table($tableName)
{
$this->db::table($tableName);
return $this->db;
}
...
}
IDatabase.php
<?php namespace Modules\Core\Interfaces;
interface IDatabase
{
public function select($str);
public function table($tableName);
public function raw($rawQuery);
public function transaction($callback);
public function first();
public function get();
}
CoreServiceProvider.php
...
public function register()
{
...
$this->app->bind('Modules\Core\Interfaces\IDatabase', function($app) {
$db = $app->make(DB::class);
return new DatabaseService($db);
});
...
}
MailboxRepository.php
<?php namespace Modules\Mailbox\Repositories;
use Illuminate\Database\Eloquent\Model;
use Modules\Core\Interfaces\IDatabase;
use Modules\Mailbox\Interfaces\IMailbox;
class MailboxRepository implements IMailbox
{
public function __construct(..., IDatabase $db)
{
...
$this->db = $db;
}
...
public function getBadges()
{
$badges = $this->db->table('mailbox as a')
->select($this->db->raw(
"SUM(a.type = 'inbox') as inbox,
SUM(a.is_read = 0 AND a.type = 'inbox') as unread,
SUM(a.type = 'sent') as sent,
SUM(a.type = 'draft') as draft,
SUM(a.type = 'outbox') as outbox,
SUM(a.type = 'spam') as spam,
SUM(a.type = 'trash') as trash,
SUM(a.is_starred = 1) as starred"
))
->first();
return $badges;
}
...
}
MailboxServiceProvider.php
<?php namespace Modules\Mailbox;
...
use Modules\Mailbox\Interfaces\IMailbox;
use Modules\Mailbox\Repositories\MailboxRepository;
use Modules\Core\Interfaces\IDatabase;
use Illuminate\Support\ServiceProvider;
class MailboxServiceProvider extends ServiceProvider
{
protected $defer = true;
public function register()
{
$this->app->bind(IMailbox::class, function($app) {
return new MailboxRepository(
..., $app->make(IDatabase::class)
);
});
}
public function provides()
{
return [IMailbox::class];
}
}
With error message :
[2018-01-31 13:45:04] local.ERROR: Call to undefined method Illuminate\Support\Facades\DB::select()
{"userId":1,"email":"info#narpandi.com","exception":"[object]
(Symfony\\Component\\Debug\\Exception\\FatalThrowableError(code: 0): Call
to undefined method Illuminate\\Support\\Facades\\DB::select() at
/var/www/personal-
website/app/Modules/Mailbox/Repositories/MailboxRepository.php:86)
How to do this correctly? Thank you for your kind help.

Answer 1

I don't think this is a common repository pattern, in repository pattern you try to create methods like:
Object get(Object id);
void create(Object entity);
void update(Object entity);
void delete(Object entity);
Edit, try to do something like docs: Database
use Modules\Core\Interfaces\IDatabase;
use Illuminate\Support\Facades\DB;
class DatabaseService implements IDatabase
{
public function select($str, $args)
{
return DB::select($str, $args);
}
}
But i say again this doesn't look like a repository.

Answer 2

After trial and error, I finally figure out how to do this. As mentioned in https://stackoverflow.com/a/26356144/3050636, you cannot use facade DB directly so instead you need to explicitly pass class that is behind the DB facade.
In my case, I use bridge pattern and fluent interface (CMIIW) so I will provide two versions:
Without bridge pattern
MailboxServiceProvider.php
<?php namespace Modules\Mailbox;
use Modules\Mailbox\Interfaces\IMailbox;
...
use Modules\Mailbox\Repositories\MailboxRepository;
use Illuminate\Support\ServiceProvider;
/* Use these instead of DB facade */
use Illuminate\Database\DatabaseManager;
use Illuminate\Database\Connectors\ConnectionFactory;
class MailboxServiceProvider extends ServiceProvider
{
protected $defer = true;
public function register()
{
$this->app->bind(IMailbox::class, function($app) {
return new MailboxRepository(
..., new DatabaseManager($app, new ConnectionFactory($app))
);
});
}
public function provides()
{
return [IMailbox::class];
}
}
MailboxRepository.php
<?php namespace Modules\Mailbox\Repositories;
use Illuminate\Database\DatabaseManager;
use Modules\Mailbox\Interfaces\IMailbox;
class MailboxRepository implements IMailbox
{
...
protected $db;
public function __construct(..., DatabaseManager $db)
{
...
$this->db = $db;
}
...
}
With bridge pattern and fluent interface
CoreServiceProvider.php
<?php namespace Modules\Core;
....
use Modules\Core\Services\DatabaseService;
use Modules\Mailbox\Repositories\MailboxRepository;
use Modules\Core\Interfaces\IDatabase;
use Modules\Mailbox\Interfaces\IMailbox;
/* Use these instead of DB facade */
use Illuminate\Database\DatabaseManager;
use Illuminate\Database\Connectors\ConnectionFactory;
use Illuminate\Support\ServiceProvider;
class CoreServiceProvider extends ServiceProvider
{
public function register()
{
...
$this->app->bind(IDatabase::class, function($app) {
return new DatabaseService(new DatabaseManager($app, new ConnectionFactory($app)));
});
$this->app->bind(IMailbox::class, function($app) {
return new MailboxRepository(
..., $app->make(IDatabase::class)
);
});
...
}
}
DatabaseService.php
<?php namespace Modules\Core\Services;
use Modules\Core\Interfaces\IDatabase;
use Illuminate\Database\DatabaseManager;
class DatabaseService implements IDatabase
{
protected $db;
public function __construct(DatabaseManager $db)
{
$this->db = $db;
}
public function select($str)
{
$this->db = $this->db->select($str);
return $this->db;
}
public function table($tableName)
{
$this->db = $this->db->table($tableName);
return $this->db;
}
...
}
MailboxRepository.php
<?php namespace Modules\Mailbox\Repositories;
use Modules\Core\Interfaces\IDatabase;
use Modules\Mailbox\Interfaces\IMailbox;
class MailboxRepository implements IMailbox
{
...
protected $db;
public function __construct(..., IDatabase $db)
{
...
$this->db = $db;
}
...
}