PHP5添加了一項新的功能：Reflection。這個功能使得程序員可以reverse-engineer class, interface,function,method and extension。通過PHP代碼，就可以得到某object的所有信息，並且可以和它交互。
假設有一個類Person：
01 |
class Person
{ |
02 |
/** |
03 |
*
For the sake of demonstration, we"re setting this private |
04 |
*/ |
05 |
private $_allowDynamicAttributes =
false; |
06 |
|
07 |
/**
type=primary_autoincrement */ |
08 |
protected $id =
0; |
09 |
|
10 |
/**
type=varchar length=255 null */ |
11 |
protected $name; |
12 |
|
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/**
type=text null */ |
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protected $biography; |
15 |
|
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public function getId() |
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{ |
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return $this->id; |
19 |
} |
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public function setId($v) |
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{ |
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$this->id
= $v; |
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} |
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public function getName() |
25 |
{ |
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return $this->name; |
27 |
} |
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public function setName($v) |
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{ |
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$this->name
= $v; |
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} |
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public function getBiography() |
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{ |
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return $this->biography; |
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} |
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public function setBiography($v) |
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{ |
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$this->biography
= $v; |
39 |
} |
40 |
} |
通過ReflectionClass，我們可以得到Person類的以下信息：
- 常量 Contants
- 屬性 Property Names
- 方法 Method Names
- 靜態屬性 Static Properties
- 命名空間 Namespace
- Person類是否爲final或者abstract
只要把類名"Person"傳遞給ReflectionClass就可以了：
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$class = new ReflectionClass('Person'); |
獲取屬性(Properties)：
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$properties = $class->getProperties(); |
2 |
foreach($properties as $property)
{ |
3 |
echo $property->getName()."\n"; |
4 |
} |
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//
輸出: |
6 |
//
_allowDynamicAttributes |
7 |
//
id |
8 |
//
name |
9 |
//
biography |
默認情況下，ReflectionClass會獲取到所有的屬性，private 和 protected的也可以。如果只想獲取到private屬性，就要額外傳個參數：
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$private_properties = $class->getProperties(ReflectionProperty::IS_PRIVATE); |
可用參數列表：
- ReflectionProperty::IS_STATIC
- ReflectionProperty::IS_PUBLIC
- ReflectionProperty::IS_PROTECTED
- ReflectionProperty::IS_PRIVATE
如果要同時獲取public 和private 屬性，就這樣寫：ReflectionProperty::IS_PUBLIC | ReflectionProperty::IS_PROTECTED
應該不會感覺陌生吧。
通過$property->getName()可以得到屬性名，通過getDocComment可以得到寫給property的註釋。
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foreach($properties as $property)
{ |
02 |
if($property->isProtected())
{ |
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$docblock = $property->getDocComment(); |
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preg_match('/
type\=([a-z_]*) /', $property->getDocComment(), $matches); |
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echo $matches[1]."\n"; |
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} |
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} |
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//
Output: |
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//
primary_autoincrement |
10 |
//
varchar |
11 |
//
text |
有點不可思議了吧。竟然連註釋都可以取到。
獲取方法(methods)：通過getMethods() 來獲取到類的所有methods。返回的是ReflectionMethod對象的數組。不再演示。
最後通過ReflectionMethod來調用類裏面的method。
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$data = array("id" =>
1, "name" => "Chris", "biography" => "I
am am a PHP developer"); |
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foreach($data as $key => $value)
{ |
03 |
if(!$class->hasProperty($key))
{ |
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throw new Exception($key."
is not a valid property"); |
05 |
} |
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|
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if(!$class->hasMethod("get".ucfirst($key)))
{ |
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throw new Exception($key."
is missing a getter"); |
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} |
10 |
|
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if(!$class->hasMethod("set".ucfirst($key)))
{ |
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throw new Exception($key."
is missing a setter"); |
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} |
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|
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//
Make a new object to interact with |
16 |
$object = new Person(); |
17 |
|
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//
Get the getter method and invoke it with the value in our data array |
19 |
$setter = $class->getMethod("set".ucfirst($key)); |
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$ok = $setter->invoke($object, $value); |
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|
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//
Get the setter method and invoke it |
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$setter = $class->getMethod("get".ucfirst($key)); |
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$objValue = $setter->invoke($object); |
25 |
|
26 |
//
Now compare |
27 |
if($value == $objValue)
{ |
28 |
echo "Getter
or Setter has modified the data.\n"; |
29 |
} else { |
30 |
echo "Getter
and Setter does not modify the data.\n"; |
31 |
} |
32 |
} |