技術情報
- 2020年10月30日
- 技術情報
[Laravel] Eloquentとページネーション(1)
nishida at 2020年10月30日 10:00:58
- 2020年10月26日
- 技術情報
Adapter Design Pattern
The adapter is a structural design pattern that enables the collaboration of objects with incompatible interfaces.
You can create an adapter. This is a special object that converts an object’s interface so that another object can understand it.
An adapter wraps one of the objects to hide the complexity of the conversion that occurs behind the scenes. The wrapped object is not even aware of the adapter. For example, you can wrap an object that operates in meters and kilometers with an adapter that converts all data to imperial units such as feet and miles.
Adapters can not only convert data into various formats, they can also help objects with different interfaces to collaborate. Is that how it works:
The adapter gets an interface, compatible with one of the existing objects.
With this interface, the existing object can safely call the adapter’s methods.
Upon receiving a call, the adapter passes the request to the second object, but in the format and order expected by the second object.
Sometimes it is even possible to create a bi-directional adapter that can convert calls in both directions.
Lets look at the example I created as below.
PHP Sample Code
<?php
/**
* The original interface that is working as normal
*/
interface Socket
{
public function input();
}
/**
* This is the simple class that follows the existing target interface `Socket`
*/
class twoPinSocket implements Socket
{
public function input()
{
echo "two pin input";
}
}
/**
* This is the conversion class (might be 3rd party service code as well) that will be used later in adapter class.
*/
class conversion
{
public function changetoThreePin()
{
echo "changed to three pin => three pin input";
}
}
/**
* This is the adapter class implementing the original target interface linking with conversion class.
* this will product the format that is second object want.
*/
class threePinSocket implements Socket
{
private $conversion;
public function __construct(conversion $conversion)
{
$this->conversion = $conversion;
}
public function input()
{
$this->conversion->changetoThreePin();
}
}
/**
* The existing twoPinSocket class that follows the target interface.
*/
$socket = new twoPinSocket();
echo $socket->input();
/**
* threePinSocket conversion that follows target interface using conversion adapter
*/
$conversion = new conversion();
$socket = new threePinSocket($conversion);
echo $socket->input();
?>
C# Sample Code
using System;
namespace HelloWorld
{
/**
* The original interface that is working as normal
*/
public interface Socket
{
string input();
}
/**
* This is the simple class that follows the existing target interface `Socket`
*/
class TwoPinSocket : Socket
{
public string input()
{
return "two pin input";
}
}
/**
* This is the conversion class (might be 3rd party service code as well) that will be used later in adapter class.
*/
class Conversion
{
public string change()
{
return "changed 2pin to 3pin";
}
}
/**
* This is the adapter class implementing the original target interface linking with conversion class.
* this will product the format that is second object want.
*/
class ThreePinSocket : Socket
{
private readonly Conversion _conversion;
public ThreePinSocket(Conversion conversion)
{
this._conversion = conversion;
}
public string input()
{
return this._conversion.change();
}
}
public class Program
{
public static void Main(string[] args)
{
/**
* The existing twoPinSocket class that follows the target interface.
*/
Socket socket = new TwoPinSocket();
Console.WriteLine(socket.input());
/**
* threePinSocket conversion that follows target interface using conversion adapter
*/
Conversion conversion = new Conversion();
Socket socket = new ThreePinSocket(conversion);
Console.WriteLine(socket.input());
}
}
}
By Yuuma
yuuma at 2020年10月26日 11:00:37
- 2020年10月23日
- 技術情報
[A5:SQL Mk-2] レコードのバックアップと復元、およびinsert文の生成について
nishida at 2020年10月23日 10:00:09
- 2020年10月19日
- 技術情報
Bridge Design Pattern
Bridge is a structural design pattern that allows you to divide a large class or a set of closely related classes into two separate hierarchies (abstraction and implementation) that can be developed independently of each other.
Bridge is a synonym for the expression “handle / body”. This is a design mechanism that encapsulates an implementation class within an interface class. The first is the body and the second is the handle. The user sees the identifier as the actual class, but the work is done in the body. “The idiom for the handle / body class can be used to decompose a complex abstraction into smaller, more manageable classes. The idiom can reflect the sharing of a single resource by multiple classes that control access to it (for example, the count of references)”.
- Decouple an abstraction from your implementation so that the two can vary independently.
- Publish the interface in an inheritance hierarchy and hide the implementation in its own inheritance hierarchy.
Lets take a look at the code samples I created as below.
PHP Code Sample
<?php
/**
* This is the original application interface
* where we place the methods need to develop from its concrete sub classes
*/
interface ApplicationInterface
{
public function setDbDriver(DbDriver $dbDriver);
public function query($query);
}
/**
* This abstract class will implements the interface as we have to reference the next hierarchy object here.
* After that we can access the methods of their sub concrete classes in our sub classes. see below.
*/
abstract class Application implements ApplicationInterface
{
protected $dbDriver;
public function setDbDriver(DbDriver $dbDriver)
{
$this->dbDriver = $dbDriver;
}
}
/**
* Concrete sub classes of the original class working with the reference object's method.
*/
class android extends Application
{
public function query($query)
{
$query .= "\n\n running android app query\n";
return $this->dbDriver->handleQuery($query);
}
}
class ios extends Application
{
public function query($query)
{
$query .= "\n\n running ios app query\n";
return $this->dbDriver->handleQuery($query);
}
}
/**
* This is the interface that need to be referenced by original class instead of inheritance.
*/
interface DbDriver
{
public function handleQuery($query);
}
/**
* Concrete classes that will have the detail implementations of the interface.
*/
class MysqlDriver implements DbDriver
{
public function handleQuery($query)
{
echo "\nUsing the mysql driver: ".$query;
}
}
class OracleDriver implements DbDriver
{
public function handleQuery($query)
{
echo "\nUsing the oracle driver: ".$query;
}
}
//client code
// client doesn't need to know any implementation details.
// Just build the original concrete class and inject the concrete object that will be referenced.
$android = new android();
$android->setDbDriver(new MysqlDriver());
echo $android->query("select * from table");
$android->setDbDriver(new OracleDriver());
echo $android->query("select * from table");
$ios = new ios();
$ios->setDbDriver(new MysqlDriver());
echo $ios->query("select * from table");
$ios->setDbDriver(new OracleDriver());
echo $ios->query("select * from table");
C# Code Sample
using System;
using System.Collections.Generic;
namespace HelloWorld
{
/**
* Two Original classes referencing the same DbDriver which is the next hierarchy object
* After that we can access the methods of their sub concrete classes in our sub classes. query method in this case
*/
class ApplicationInterface
{
protected DbDriver _dbdriver;
public ApplicationInterface(DbDriver dbdriver)
{
this._dbdriver = dbdriver;
}
public virtual string setDbDriver()
{
return "Base DB Driver:" +
_dbdriver.query();
}
}
class RefinedAbstraction : ApplicationInterface
{
public RefinedAbstraction(DbDriver dbdriver) : base(dbdriver)
{
}
public override string setDbDriver()
{
return "Refined DB Driver:" +
base._dbdriver.query();
}
}
/**
* This is the interface that need to be referenced by original class instead of inheritance.
*/
public interface DbDriver
{
string query();
}
/**
* Concrete classes that will have the detail implementations of the interface.
*/
class MysqlDriver : DbDriver
{
public string query()
{
return "Using the mysql driver:\n";
}
}
class OracleDriver : DbDriver
{
public string query()
{
return "Using the oracle driver:.\n";
}
}
// client doesn't need to know any implementation details.
// Just build the original class and inject the concrete object that will be referenced.
class Client
{
public void ClientCode(ApplicationInterface applicationInterface)
{
Console.Write(applicationInterface.setDbDriver());
}
}
class Program
{
static void Main(string[] args)
{
Client client = new Client();
ApplicationInterface applicationInterface;
applicationInterface = new ApplicationInterface(new MysqlDriver());
client.ClientCode(applicationInterface);
Console.WriteLine();
applicationInterface = new RefinedAbstraction(new OracleDriver());
client.ClientCode(applicationInterface);
}
}
}
yuuma at 2020年10月19日 11:00:17
- 2020年10月16日
- 技術情報
[Laravel] Passportを使用したBearer token認証[4]
今回はPHPのLaravelフレームワークのPassportを使用したBearer token認証の方法について紹介します。
本記事は前回の「[Laravel] Passportを使用したBearer token認証[3]]」の続きとなります。
今回は前回追加した認証テスト用ユーザーを使用してBearer tokenの発行と認証のテストをおこなっていきたいと思います。
nishida at 2020年10月16日 10:00:55