I have a project. I need to get the contents of a file in a package. I could do it the hard way:
file_get_contents('../../vendor/{vendor}/{package}/src/
{directory}/{sub-directory}/class.php');
Or, I could do it the "easy way," which I'm pretty sure is impossible.
namespace MyVendor\MyProject;
use TheirVendor\TheirPackage\TheirClass;
class MyObject
{
public function myFunction()
{
return file_get_contents(TheirClass);
}
}
Is this (or something like it) possible?
You can get the file name of where a class is declared using a ReflectionClass instance and its getFileName() method:
$reflector = new ReflectionClass(\Vendor\Package\Class::class);
echo $reflector->getFileName();
You could use the __NAMESPACE__ global and then replace the backslash with the proper directory separator, then use the __FILE__ global to append the filename
$ns = str_replace( __NAMESPACE__, DIRECTORY_SEPARATOR, '\\' );
$path = $ns.DIRECTORY_SEPARATOR.__FILE__;
and then do what you want with it.
Related
It should be easy to load a file using a namespace, but I cannot seem to generate the url to it. The file is located in the same directory as MyClass, where it is called from.
<?php namespace Mynamespace\Subnamespace;
class MyClass {
public function getFile() {
$fileLocation = 'myfile.json'; // file is located next to this class in Mynamespace\Subnamespace\file.json
return file_get_contents( $fileLocation );
}
}
The closest solution I found is using the method getFileName() in a ReflectionClass of MyClass. But that returns the full url including the class MyClass.php file. And using a regExp on that seems overkill, since there is probably an easier solution.
If a namespace can somehow be converted into a valid url, that should do the trick.
How should file.json be retreived?
You can't use namespaces for JSON files. But since it is in the same directory as the class you should be able to use __DIR__
<?php namespace Mynamespace\Subnamespace;
class MyClass {
public function getFile() {
$fileLocation = 'myfile.json';
return file_get_contents( __DIR__ . PATH_SEPARATOR . $fileLocation );
}
}
The easiest way to do this is with get_class
<?php namespace Mynamespace\Subnamespace;
class MyClass {
public function getFile() {
// Will have backslashes so str_replace if this is a Unix environment
$path = str_replace('\\', '/', get_class($this));
$fileLocation = $path . '/myfile.json'; // Mynamespace/Subnamespace/myfile.json
return file_get_contents( $fileLocation );
}
}
If I understand correctly, just this:
$fileLocation = __NAMESPACE__ . '\myfile.json';
See PHP: namespace keyword and __NAMESPACE__ constant.
But since you state "file is located next to this class in Mynamespace\Subnamespace\file.json" then you can just use the full path to the current file:
$fileLocation = __DIR__ . '\myfile.json'; // or dirname(__FILE__)
See PHP: Magic Constants.
I am using an autoloader which includes classes based on WordPress naming convention, meaning, My_Class should reside in class-my-class.php. It works fine. However, I have to use a third party library, which is differently named and doesn't use a namespace. How would I use it in my code? Do I need to include it explicitly?
A \ before the beginning of a class represents the global namespace.
my.class.php
<?php
class myClass {
}
?>
index.php
<?php
require( 'my.class.php' );
$obj = new \myClass;
var_dump( $obj );
?>
Anyway, if you want to autoload a class without namespace, you can use the following trick in your autoloader:
if ( file_exists( $filepath = str_replace( '\\', '/', $class ) ) {
require $filepath;
}
$obj = \myClass;
I keep trying to know what the problem is with this very simple class loader script.
The class loader looks like this:
#src/vendors/Autoloading/lib/ClassLoader.php
namespace App\Vendors\Autoloading;
class ClassLoader
{
private $path;
function __construct($path)
{
$this->path = $path;
}
public function load($class)
{
if(file_exists( $class = str_replace(array('\\', '_'), DIRECTORY_SEPARATOR, $this->path) . '.php')){
require $class;
return true;
}
}
public function register()
{
return spl_autoload_register([$this, 'load']);
}
}
The initial class loader had more methods and some functions to validate the file names ...
but, in the process of debugging I had to narrow it to that.
So, that class loader is being required inside an autoload.php file, as you can see below.
#src/vendors/autoload.php
namespace App\Vendors;
require 'Autoloading/lib/ClassLoader.php';
$autoload = new Autoloading\ClassLoader('path/Foo/FooClass');
$autoload->register();
The FooClass.php is located in src/Foo/FooClass.php
namespace App\Foo;
class FooClass{}
and there is actually no problem with the autoloading part, the class gets loaded just fine, but it is done twice which shows me the below error. I am calling it from an index.php file
<?php
use \App\Foo\FooClass;
FooClass::somefunction();
Just using that generates this error.
Fatal error: Cannot redeclare class path\foo\FooClass in /path/to/index.php on line 4
Your autoloading function is wrong:
public function load($class)
{
if (
file_exists(
$class = str_replace(
array('\\', '_'),
DIRECTORY_SEPARATOR,
$this->path)
. '.php')
) {
require $class;
return true;
}
}
The function is calles with the name of the class to be loaded (if impossible, the function should do nothing).
What you do is ignoring the class name, and create a new one based on the path the autoloader is created with. This will always load the same file, with the same class, even if there are different classes to be loaded.
And this explains why you get the error, because no matter which class name gets passed, you always include the one file that is related to the path.
You probably want to use a proper PSR-0 or PSR-4 autoloader. I would recommend using the one that comes with Composer, as you are likely to be using Composer sooner or later yourself. Why not starting today?
Check if the class already exists using class_exists before checking for the file
Try using require_once instead of require. Your autoloader won't keep track of what files have been loaded so far.
Here's how I set mine up. I don't use a class. Maybe this will help
function PlatformAutoloader($classname) {
try {
// Change \ to / so namespacing will work
$classname = strtolower(str_replace('\\', DIRECTORY_SEPARATOR, $classname));
if(!#include_once(DIR_CLASSES . DIRECTORY_SEPARATOR . $classname . '.php')) return false;
} catch(Exception $e) {
return false;
}
}
spl_autoload_register('PlatformAutoloader');
recently I was learning zend framework 2, and there's a problem annoying me for a long time, things look like this:
<?php
namespace Album\Model;
// Add these import statements
use Zend\InputFilter\InputFilter;
use Zend\InputFilter\InputFilterAwareInterface;
use Zend\InputFilter\InputFilterInterface;
class Album implements InputFilterAwareInterface
{
public $id;
public $artist;
public $title;
protected $inputFilter;
public function exchangeArray($data)
{
$this->id = (isset($data['id'])) ? $data['id'] : null;
$this->artist = (isset($data['artist'])) ? $data['artist'] : null;
$this->title = (isset($data['title'])) ? $data['title'] : null;
}
// Add content to these methods:
public function setInputFilter(InputFilterInterface $inputFilter)
{
throw new \Exception("Not used");
}
//....
?>
This code was a section of the "skeleton application" programme， which was a tutorial of ZF2. The first time I see the programme, I don't understand what's the usage of "namespace" and "use", because this two keyword doesn't exist in php5.2(also the same in the earlier edition), so I go to see the manual and try to understand it.I write a programme to simulate what really happens:
<?php
use script\lib\test;
$o = new test();
echo $o->getWelcome();
function __autoload( $className ) {
$classname = strtolower( $classname );
require_once( dirname( __FILE__ ) . '/' . $classname . '.php' );
}
?>
the programme above works well, of course I created two folders named script and lib, and there's a file named test.php.
Seems like every thing is clear, zend framework also has a autoload function, BUT when I noticed the codes in "skeleton application programme", there was a namespace in the beginning, so I adds the namespace to my programme too:
<?php
namespace test;
use script\lib\test;
$o = new test();
echo $o->getWelcome();
function __autoload( $className ) {
$classname = strtolower( $classname );
require_once( dirname( __FILE__ ) . '/' . $classname . '.php' );
}
?>
the page returned me inforamtion as following:
Fatal error: Class 'script\lib\test' not found in E:\wamp\www\test\test_29.php on line 6
I tried to change the namespace's name such as script\lib, script\lib\test...
but it's useless.
Any answer will be appreciated, thanks.
Now I will give you more details about this issue:
To understand the usage of "namespace" and "use", I looked over the materials on php.net:
http://php.net/manual/en/language.namespaces.importing.php
In this page, there was a section of code looks like this:
Example #1 importing/aliasing with the use operator
<?php
namespace foo;
use My\Full\Classname as Another;
// this is the same as use My\Full\NSname as NSname
use My\Full\NSname;
// importing a global class
use ArrayObject;
$obj = new namespace\Another; // instantiates object of class foo\Another
$obj = new Another; // instantiates object of class My\Full\Classname
NSname\subns\func(); // calls function My\Full\NSname\subns\func
$a = new ArrayObject(array(1)); // instantiates object of class ArrayObject
// without the "use ArrayObject" we would instantiate an object of class
?>
Now let's review the programme I write in the above:
<?php
namespace test;
use script\lib\test;
$o = new test();
echo $o->getWelcome();
function __autoload( $className ) {
$classname = strtolower( $classname );
require_once( dirname( __FILE__ ) . '/' . $classname . '.php' );
}
?>
It's the same, I'm trying to simulate that instance, if we don't use the autoload function:
<?php
namespace test;
use script\lib\test;
require_once 'script/lib/test.php';
$o = new test();
echo $o->getWelcome();
?>
It works well too, BUT when I use __autoload function to load the class file, there's something wrong.
I don't konw where's problem, OR any body tried to write an instance to put the "Example #1" into practice? I will wait for your answer.
I think you're misunderstanding what's going on here.
Namespaces allow you to, more or less, create "directories" for your classes. So you can create the \Foo class and the \Test\Foo class (where \ represents the "root" of your application).
The way autoloading works is that your files mirror your namespacing. So foo.php would be in the root of your autoloading but you would create /test/foo.php for \Test\Foo
The use keyword has two uses. One is to alias class files and the other is, in PHP 5.4 or later, to bring in a Trait into your current class.
Now, to your question. First, Let's look at your code
<?php
namespace test;
use script\lib\test;
$o = new test();
echo $o->getWelcome();
This is confusing. You declare a namespace (which you don't need to do here) but then you alias it to script\lib\test. PHP is now looking for a file called /script/lib/test.php, which your error message says doesn't exist. But you said the file does exist so let's look at that
public function getWelcome() {
return 'welcome';
}
This isn't a class. It's a function. For this example you need a complete class
<?php
namespace script\lib;
class test {
public function getWelcome() {
return 'welcome';
}
}
Lastly, let's talk autoloading. You don't need to use use with autoloading. Your autoloader should take care of that for you. You should, however, use spl_autoload_register(), as __autoload() is soon to be depreciated.
From ZF2 docu
Zend\Loader\StandardAutoloader is designed as a PSR-0-compliant autoloader. It assumes a 1:1 mapping of the namespace+classname to the filesystem, wherein namespace separators and underscores are translated to directory separators.
Read more about: PSR-0
So if you're using namespaces the classname that gets send to the autoloader doesn't look like test. It looks like YOUR_NAMESPACE\test. YOUR_NAMESPACE is the namespace that you defined in the class with namespace YOUR_NAMESPACE;
PSR-0 is a standard that says: Your namespace should reflect your filesystem. You only have to replace the backslashes with forward slashes. Or _ with / if you're using pseudo namespaces like in ZF1. (Album_Model_Album)
So output the $className that is sent to your autoloader and you will see..
I have the following directory structure:
/var/www/Project1/Project1.php
/var/www/Project1/User/UserProfile.php
Inside Project1.php:
<?php
namespace Project1;
set_include_path( __DIR__ );
spl_autoload_extensions('.php');
spl_autoload_register();
use User\UserProfile;
$u = new Avatar();
...
?>
Inside UserProfile.php:
<?php
namespace Project1\User;
class Avatar{
}
...
?>
When I execute php Project1.php I get:
PHP Fatal error: spl_autoload9(): Class User\UserProfile could not be loaded
I don't see the problem.
spl_autoload_register(); when called with no params will just register the default autoloader which fails to handle namespaces with your project layout. You'll have to register your own method to make it work. Like this:
spl_autoload_register('my_autoload');
And here comes the autoload function. This function expects the classes to be stored in a way like:
/path/to/project/Namespace/Classname.php
/path/to/project/Namespace/Subnamespace/Classname.php
You can name the classes like \Namespaces\Classname or the old style way Namespace_Classname:
function my_autoload ($classname) {
// if the class where already loaded. should not happen
if (class_exists($classname)) {
return true;
}
// Works for PEAR style class names and namespaced class names
$path = str_replace(
array('_', '\\'),
'/',
$classname
) . '.php';
if (file_exists('/path/to/project/' . $tail)) {
include_once 'path/to/project/' . $tail;
return true;
}
return false;
}
Note that the function is taken from my github package Jm_Autoloader. The package provides more functionality as multiple include paths, path prefixes and static autoloading (with a predefined assoc array class name => file name). You can use it if you like ;)