Introduction to PHP Reflection
Reflection of PHP Programming Language usually defined as some program’s ability of inspecting itself and then modifying the logic itself at the time of program execution. In normal terms the reflection of PHP is useful in asking the object which tells you about some of its methods and the properties and those altering members and those altering members may even contains the private ones. Without the PHP reflection concept, the duck-typing is mostly impossible in implementing. Reflection concept of PHP helps in identifying the methods which cannot or can be called on some received object. It is the most useful concept in the PHP programming language just like some special programming languages like Java, Ruby, etc.
Syntax:
<?php
Class myClass1{
…
}
$myClassObj = new myClass();
$myClassRef = new ReflectionClass($myClassObj);
?>
Instead of ReflectionClass() we can use different types of Reflection Classes based on our requirement.
How Does Reflection Work in PHP?
The reflection concept of the PHP Programming Language basically wor5ks just by defining the ability to inspect the program itself and then it helps in modifying the logic itself at the exact instance of the time of the program execution.
Types of Classes in PHP Reflection
There are some different types of classes available which helps in the working of the PHP Reflection concept.
1. ReflectionClass Class: The ReflectionClass is helpful in providing information about the specific class
2. ReflectionFunction Class: The ReflectionClass is helpful in reporting the information about a specific function
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3. ReflectionMethod: The ReflectionMethod is helpful in reporting the information about a specific method
4. ReflectionParameter: The ReflectionParameter is helpful in retrieving the information about the specific method’s or specific function’s parameters.
5. ReflectionProperty Class: The ReflectionProperty Class is helpful in providing information about some properties.
6. ReflectionObject Class: The ReflectionObject Class is helpful in providing information about a specific object.
Methods in PHP Reflection
The PHP Reflection Class is available with different methods.
1. getProperties Method: The getProperties Method of the PHP ReflectionClass is helpful in getting all the class properties.
2. getMethods Method: The getMethods Method of the PHP ReflectionClass Class is helpful in getting all the methods of the specific class.
3. getDocComment Method: The getDocComment Method of the PHP ReflectionClass Class is helpful in getting the specific Class Document Comment.
4. getFileName Method: The getFileName Method of the PHP ReflectionClass Class is helpful in getting the file name of the specific file where the specific class is defined.
5. getParentClass Method: The getParentClass Method of the PHP ReflectionClass Class is helpful in getting the parent class.
6. hasMethod Method: The hasMethod method of the PHP ReflectionClass Class is helpful in checking whether the specific method is defined or not.
Examples to Implement PHP Reflection
Now, we will see PHP Reflection property with the examples as described below:
Example #1
This is the example of implementing the Reflection Concept of the PHP Programming Language. Here at first a class “X1” is created with no content in it. Then class_alias() function is used with “X1”, “Y1” and “Y1“, “Z1”. Then a new variable called “Z1” is created with the new ReflectionClass concept. Then it’s object/method is called with the help of the echo statement and with the help of the getName() function. This program is mainly used for the reflection of the specifically resolved class. Check out the output so that you can understand the reflection is done and shows the X1 class only as a display print.
Code:
<?php
class X1 {
}
class_alias('X1','Y1');
class_alias('Y1','Z1');
$z1 = new ReflectionClass('Z1');
echo $z1->getName(); // X1
?>
Output:
Example #2
This is the example of implementing the ReflectionMethod Class Concept of the PHP Programming Language. Here at the first inside of the PHP tags, Class A1 is created with the public function_construct() then class B1 is created which helps in extending to the A1. Then a variable called “method1” is created with the new ReflectionMethod() Then method1’s object will be printed with the help of the echo statement. Then the PHP tags will be closed. Here the public member’s class which actually contains the name of the specific class in which the specific method has to be defined. Check out the output which shows “A1” as output because of the reflection concept.
Code:
<?php
class A1 {public function __construct() {}}
class B1 extends A1 {}
$method1 = new ReflectionMethod('B1', '__construct');
echo $method1->class; // prints 'A1'
?>
Output:
Example #3
This is the example of the PHP code snippet of the Reflection Concept. Here I created a simple class with only just two properties and also with two methods. Here we used some reflection classes which are used to populate the specific properties dynamically and then I make them to print. Here at first, a class A1 is created then constructors are created. Then echo is used to print the object variables then new objects are created and then used ReflectionClass() and then foreach concept is used to print different values that are present inside the class A1. Just check the PHP Reflection example to understand the output.
Code:
<?php
class A1
{
public $one1 = '';
public $two1 = '';
//PHP Constructor
public function __construct()
{
//PHP Constructor
}
//print variable one1
public function echoOne1()
{
echo $this->one1."\n";
}
//print variable two1
public function echoTwo1()
{
echo $this->two1."\n";
}
}
//Instantiate the PHP object
$a1 = new A1();
//Instantiate the PHP reflection object
$reflector1 = new ReflectionClass('A1');
//Now i am getting all the properties from class A1 in to $properties1 array
$properties1 = $reflector1->getProperties();
$i1 =11;
//Now go through the PHP $properties1 array and populate each property1
foreach($properties1 as $property1)
{
//Populating properties1
$a1->{$property1->getName()}=$i1;
//Invoking the PHP method here to print with echo statement which was actually populated
$a1->{"echo".ucfirst($property1->getName())}()."\n";
$i1++;
}
?>
Output:
Advantages of PHP Reflection
Below are the advantages of PHP Reflection:
- With the reflection concept, Dynamic typing is possible.
- Aspect-Oriented Programming is possible with PHP Reflection just by listening from the method calls and then places the code around some methods.
- It is very helpful like other frameworks.
- It helps in initializing the models, constructing all the objects for views, and many more. Laravel helps the usage of reflection concepts which helps in injecting dependencies.
- It helps in meta programming.
- It helps in understanding the code with the help of the code analysis frameworks.
- HTML Form Generation.
- Helps in creating some Database Tables.
- Helps in creating some documentation of the poorly documented third parties class/classes.
- Helps in accessing private methods and private properties.
Conclusion
we hope you learned what is the definition on PHP reflection along with its syntax and explanation, How the Reflection works in PHP Programming Language script along with various examples of PHP reflection, Advantages of PHP Reflection, etc. to understand Reflection of PHP concept better.
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