Home > Backend Development > PHP Tutorial > PHP inheritance method to obtain subclass name_PHP tutorial

PHP inheritance method to obtain subclass name_PHP tutorial

WBOY
Release: 2016-07-13 17:42:20
Original
1013 people have browsed it

After looking at the introduction of datastore, and starting to use MVC method to write PHP, I wanted to use PHP to write a model for redis, which can realize some basic functions of datastore... So I encountered such a problem-.-
Things like __CLASS__ in PHP are statically bound. If they are not overloaded in a subclass, what you get by inheriting the parent class method is still the name of the parent class instead of the name of the subclass. For example:
class A{
function __construct(){
echo __CLASS__;
}
static function name(){
echo __CLASS__;
}
}
class B extends A{}

At this time, whether B is instantiated or the static method is directly called, the echo will be A. Qeephp uses subclass overloading to solve this problem, but if you don't create a new subclass, you have to overload the corresponding method of calling the class name... This is considered a defect of PHP in OOP. , I tried python and there was no such problem.
Google it. Find two functions get_class() and get_called_class(). get_class() is used for instance calls. Adding parameters ($this) can solve the problem of subclass inheritance calls, while get_called_class() is used for static method calls, but... this thing is only available after PHP 5.3. ...5.3 is still a long way off... Fortunately, this function can be implemented manually before 5.2: refer to http://php.net/manual/en/function.get-called-class.php. Some experts have added a few below. A pre-5.3 implementation.

if(!function_exists(get_called_class)) {
class class_tools
{
private static $i = 0;
private static $fl = null;
public static function get_called_class()
{
$bt = debug_backtrace();
//Use the call_user_func or call_user_func_array function to call the class method. The processing is as follows
if (array_key_exists(3, $bt)
&& array_key_exists(function, $bt[3])
&& in_array($bt[3][function], array(call_user_func, call_user_func_array))
) {
//If the parameter is an array
if (is_array($bt[3][args][0])) {
$toret = $bt[3][args][0][0];
return $toret;
}else if(is_string($bt[3][args][0])) {//If the parameter is a string
//If it is a string and the string contains the :: symbol, it is considered to be the correct parameter type, and the class name is calculated and returned
if(false !== strpos($bt[3][args][0], ::)) {
$toret = explode(::, $bt[3][args][0]);
return $toret[0];
}
}
}
//Use the normal way to call class methods, such as:A::make()
if(self::$fl == $bt[2][file].$bt[2][line]) {
self::$i++;
} else {
self::$i = 0;
self::$fl = $bt[2][file].$bt[2][line];
}
$lines = file($bt[2][file]);
preg_match_all(
/([a-zA-Z0-9_]+)::.$bt[2][function]./,
$lines[$bt[2][line]-1],
$matches
);
return $matches[1][self::$i];
}
}
function get_called_class()
{
return class_tools::get_called_class();
}
}

So now you can modify the example like this:

class A{
function __construct(){
echo get_class($this);
}
static function name(){
echo get_called_class();
}
}
class B extends A{}
This will allow B to directly inherit the method of obtaining the current class name~

www.bkjia.comtruehttp: //www.bkjia.com/PHPjc/486067.htmlTechArticleAfter looking at the introduction of datastore, and starting to use MVC to write PHP, I wanted to use PHP to write a redis model, which can implement some basic functions of datastore...So I encountered such a problem...
source:php.cn
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template