PHP 依賴注入

zengdongbao 發(fā)布于2019-07-01 10:59 / 1386人閱讀

摘要：通常調(diào)用一個(gè)類里面的方法需要如何操作依賴注入模式用來減少程序間的耦合依賴注入共有三種模式方法注入著重說下方法注入并結(jié)合單例注冊(cè)的服務(wù)數(shù)組訪問接口測試郵件發(fā)送成功方式訪問通過數(shù)組的方式訪問也是通過該方式實(shí)現(xiàn)依賴

通常調(diào)用一個(gè)類里面的方法需要如何操作：

$class = new class();
$class->fun()

依賴注入模式用來減少程序間的耦合

依賴注入共有三種模式： setter 方法注入

著重說下setter方法注入并結(jié)合ArrayAccess

/**
 * Class Di
 * @property People
 */
class Di implements ArrayAccess
{
    /**
     * 單例
     * @var null
     */
    protected static $instance = null;

    /**
     * 注冊(cè)的服務(wù)
     * @var array
     */
    protected $data = array();

    public function __construct()
    {
        echo "__construct". "
";
    }

    public function onConstruct(){
        echo "onConstruct". "
";
    }

    public static function one(){
        if (self::$instance == null) {
            self::$instance = new Di();
            self::$instance->onConstruct();
        }
        return self::$instance;
    }

    public function get($name, $default = NULL) {
        if (!empty($default)) {
            return $default;
        }

        return $this->data[$name];
    }

    public function set($name, $value) {
        $this->data[$name] = $value;
    }

    public function __get($name)
    {
        return $this->get($name);
    }

    public function __set($name, $value)
    {
        $this->set($name, $value);
    }


    /** ArrayAccess數(shù)組訪問接口 **/

    public function offsetSet($offset, $value) {
        $this->set($offset, $value);
    }

    public function offsetGet($offset) {
        return $this->get($offset, NULL);
    }

    public function offsetUnset($offset) {
        unset($this->data[$offset]);
    }

    public function offsetExists($offset) {
        return isset($this->data[$offset]);
    }

}

class People {

    protected $name = "測試";
    public function getName(){
        return $this->name;
    }

}

class Email {

    public function sendEmail($email){
        return "郵件發(fā)送成功！";
    }

}

$di = Di::one();
/** @var get set 方式訪問 people */
$di->people = new People();
$people = $di->people;
echo $di->people->getName();

/** 通過數(shù)組的方式訪問 **/
$di["Email"] = new Email();
echo $di["Email"]->sendEmail("33@qq.com");

Phalapi也是通過該方式實(shí)現(xiàn)依賴注入 
依賴注入相當(dāng)于一個(gè)注冊(cè)中心，通過魔術(shù)方法__set __get進(jìn)行賦值和取之操作，$di->email
implements ArrayAccess 可以實(shí)現(xiàn)通過數(shù)組的方式進(jìn)行操作$di["Email"]

構(gòu)造方法注入

通過__construct出入類

class a
{
    public function test() {
        echo "test";
    }
}

class c
{
    protected $s;
    public function __construct($a)
    {
        $this->s = $a;
    }

    public function test(){
        $this->s->test();
    }
}

$a = new a();
$c = new c($a);
$c->test();

接口注入

interface sql{

    public function connect();
    public function query();
}


class mysql implements sql {

    public function connect()
    {
        echo "連接mysql成功". "
";
    }

    public function query()
    {
        // TODO: Implement query() method.
    }
}

class sqlServe implements sql {

    public function connect()
    {
        echo "連接sqlServe成功". "
";
    }

    public function query()
    {
        // TODO: Implement query() method.
    }
}

class Demo{

    public $sql;

    public function __construct(sql $sql)
    {
        $this->sql = $sql;

    }
}

$mysql = new mysql();
$sqlServe = new sqlServe();

(new Demo($mysql))->sql->connect();