PHP's reflection class ReflectionClass, ReflectionMethod usage examples, reflectionmethod

PHP's reflection class ReflectionClass, ReflectionMethod usage examples, reflectionmethod_PHP tutorial

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Release： 2016-07-13 10:21:26

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Usage examples of PHP’s reflection class ReflectionClass and ReflectionMethod, reflectionmethod

PHP5 has a complete reflection API, adding the ability to reverse engineer classes, interfaces, functions, methods and extensions.

What is reflection?

It refers to extending the analysis of PHP programs in the running state of PHP and exporting or extracting detailed information about classes, methods, properties, parameters, etc., including comments. This function of dynamically obtaining information and dynamically calling methods of objects is called reflection API. Reflection is an API for manipulating meta-models in the object-oriented paradigm. It is very powerful and can help us build complex and scalable applications.

Its uses include: automatically loading plug-ins, automatically generating documents, and can even be used to expand the PHP language.

The PHP reflection api consists of several classes that help us access the metadata of the program or interact with related annotations. With the help of reflection, we can obtain the methods implemented by the class, create an instance of the class (different from creating with new), call a method (also different from the regular call), pass parameters, and dynamically call the static methods of the class.
Reflection API is PHP's built-in OOP technology extension, including some classes, exceptions and interfaces. Used together, they can be used to help us analyze other classes, interfaces, methods, properties, methods and extensions. These OOP extensions are called reflection.

Usually we use the ReflectionClass class and ReflectionMethod class more often, for example:

Copy code The code is as follows:

class Person {

/**
* For the sake of demonstration, we"re setting this private
*/
private $_allowDynamicAttributes = false;

/**
* type=primary_autoincrement
*/
protected $id = 0;

/**
* type=varchar length=255 null
*/
protected $name;

/**
* type=text null
*/
protected $biography;

public function getId() {
Return $this->id;
}

public function setId($v) {
$this->id = $v;
}

public function getName() {
Return $this->name;
}

public function setName($v) {
$this->name = $v;
}

public function getBiography() {
return $this->biography;
}

public function setBiography($v) {
$this->biography = $v;
}
}

1. Through ReflectionClass, we can get the following information of the Person class:

1.Constants
2. Property Property Names
3. Method Method Names static
4. Properties Static Properties
5. Namespace Namespace
6.Whether the Person class is final or abstract
7. Does the Person class have a certain method

Next to reflect it, just pass the class name "Person" to ReflectionClass:

Copy code The code is as follows:

$class = new ReflectionClass('Person'); // Create a reflection class for the Person class
$instance = $class->newInstanceArgs($args); // Equivalent to instantiating the Person class

1) Get properties:

Copy code The code is as follows:

$properties = $class->getProperties();
foreach ($properties as $property) {
echo $property->getName() . "n";
}
// Output:
// _allowDynamicAttributes
// id
// name
// biography

By default, ReflectionClass will obtain all properties, including private and protected ones. If you only want to get the private attribute, you need to pass an additional parameter:

Copy code The code is as follows:

$private_properties = $class->getProperties(ReflectionProperty::IS_PRIVATE);

Available parameter list:

Copy code The code is as follows:

ReflectionProperty::IS_STATIC
ReflectionProperty::IS_PUBLIC
ReflectionProperty::IS_PROTECTED
ReflectionProperty::IS_PRIVATE

The property name can be obtained through $property->getName().

2) Get comments:

You can get the comments written to the property through getDocComment.

Copy code The code is as follows:

foreach ($properties as $property) {
if ($property->isProtected()) {
$docblock = $property->getDocComment();
preg_match('/ type=([a-z_]*) /', $property->getDocComment(), $matches);
echo $matches[1] . "n";
}
}
// Output:
// primary_autoincrement
//varchar
// text

3) Get the method of the class

Copy code The code is as follows:

getMethods() to get all methods of the class.
hasMethod(string) Whether a certain method exists
getMethod(string) Get method

4) Execution class method:

Copy code The code is as follows:

$instance->getName(); // Execute the method getName
in Person // Or:
$method = $class->getmethod('getName'); // Get the getName method in the Person class
$method->invoke($instance); // Execute getName method
// Or:
$method = $class->getmethod('setName'); // Get the setName method in the Person class
$method->invokeArgs($instance, array('snsgou.com'));

2. Through ReflectionMethod, we can get information about a method of the Person class:

1. Whether it is of “public”, “protected”, “private” or “static” type
2. Parameter list of method
3. Number of parameters of the method
4. Uncall the method of the class

Copy code The code is as follows:

//Execute detail method
$method = new ReflectionMethod('Person', 'test');

if ($method->isPublic() && !$method->isStatic()) {
echo 'Action is right';
}
echo $method->getNumberOfParameters(); //Number of parameters
echo $method->getParameters(); // Parameter object array