I'm trying to create a system that would autoload classes when they're needed.
This is my folder structure
| index.php
| app
| - app.php
| - core
| -- core.php
| -- helpers
| --- htmlhelper.php
where index.php is the bootstrap file, core.php is the core file I'd like to extend and all the classes in the helpers folder would contain classes I'd like to autoload.
Since autoloading on my own is a fairly new thing for me I'm pretty confused on how to do it. I can autoload the core file, but I cannot seem to figure out how to autoload the helper classes.
This is the code I have so far:
index.php
require_once('app/app.php');
$app = new App();
$app->display();
app.php
use App\Core\Core as Core;
// autoload
spl_autoload_extensions(".php");
spl_autoload_register();
class App{
function __construct(){
//Core::addStyle('/file/css/foo1.css');
Core::foo();
}
public function display(){
Core::getStyles();
}
}
core.php
namespace App\Core;
// dependancies
use App\Core\Helpers\HtmlHelper as Helper;
// autoload
spl_autoload_extensions(".php");
spl_autoload_register();
class Core
{
function foo(){
var_dump('bar');
}
}
htmlhelper.php
namespace App\Core\Helpers;
class HtmlHelper extends Core{
protected $styles;
protected $scripts;
public static function addStyle($data){
if(is_array($data)){
$this->styles = array_merge($this->styles, $data);
}else{
$this->styles[] = $data;
}
}
public static function getStyles(){
var_dump($this->styles);
}
}
With the code I have now the core class gets autoloaded fine, and I can call the foo() method, but the htmlhelper class won't get loaded. I know this because PHP throws an error that getStyles() is undefined.
I'm doing this to achieve one exit point for the core functions of the application, but separate the code in different files.
Ideally I'd like to load all classes in the helper folder automatically and not have to put a block of use .. definitions, if that's doable.
I think that the lack of knowledge about php namespacing is my biggest flaw at this point.
I can't seem to find any good sources that would fully explain how would I do these things in a simple language for dummies.
Related
I did brows through that question page but the answers given, I felt, didn't sufficiently answer the question I was struggling with.
I have a little php project. In this project I define two classes both in their own files. The second class extends the first class. In the app.php file I instantiate the second class and call a method.
├── Models/
│ ├── Class1.php
│ └── Class2.php
└── app.php
<?php
// Class1.php
namespace Models\Class1;
/**
* Class1 does things
*/
class Class1 {
public function someMethod() {
// code
}
}
<?php
// Class2.php
namespace Models\Class2;
use \Models\Class1\Class1;
include('./Class1.php');
/**
* Class2 does other things
*/
class Class2 extends Class1 {
public function someMethod() {
// code
}
}
<?php
// app.php
use Models\Class1\Class1;
use Models\Class2\Class2;
require('Models/Class1.php');
require('Models/Class2.php');
$c1 = new Class1();
$c2 = new Class2();
Now I'm not a really experienced php programmer but I thought I had a solid grasp of this class/namespace business and including/requiring files, but apparently I don't.
If I copy the methods I need from Class1 to Class2 and not extend/include/use Class2 everything works fine, but want to extend Class1, so I don't have to repeat myself! Damn it!
This is what I get when running the app.php file.
Warning: include(../Models/Class1.php): failed to open stream: No such file or directory in C:\wamp64\www\project\Models\Class2.php on line 8
Warning: include(): Failed opening '../Models/Class1.php' for inclusion (include_path='.;C:\php\pear') in C:\wamp64\www\project\Models\Class2.php on line 7
I've been reading all I can find online about this stuff, have written and rewritten my code in a dozen different ways but have yet to find a solution. Some help would be greatly appreciated!
Quick Answer
Unless you've specified the full path to the include file, PHP will always try to resolve files according to the location of the entry script. In your case, your entry script seems to be app.php at the root of the application.
So in your Class2.php, instead of include('./Class1.php');, you should write include('Models/Class1.php'); and things should work. But while it fix a short term problem, your code would be really non-portable. Besides, including the same file twice would result in another error (e.g. re-declaring class).
Slightly Smarter Approach
A slightly smarter would be to do this in Class2.php instead.
<?php
// Class2.php
namespace Models\Class2;
use \Models\Class1\Class1;
include_once __DIR__ . '/Class2.php';
/**
* Class2 does other things
*/
class Class2 extends Class1 {
public function someMethod() {
// code
}
}
The variable __DIR__ will always be resolved to the directory of the script file, not the entry script.
But again, it is clumsy and error prone to do file includes by hand.
An Even Smarter Approach: Autoload
PHP supports file autoloading when a class is declare. That is to have a piece of code to do the file include when a class is called. If you want to have fun, you're welcome to write your own autoloader function and register to spl_autoload_register. With a combination of the __DIR__ technique we talked about, you can easily resolve the autoloading path from namespace.
A quick and ugly autoloading app.php would probably look like this:
<?php
// app.php
use Models\Class1\Class1;
use Models\Class2\Class2;
spl_autoload_register(function ($class_name) {
$realClassName = basename(str_replace('\\', DIRECTORY_SEPARATOR, $class_name));
include_once __DIR__ . DIRECTORY_SEPARATOR . 'Models' . DIRECTORY_SEPARATOR . $realClassName . '.php';
});
$c1 = new Class1();
$c2 = new Class2();
The Smart Approach: Composer Autoload
If you're learning OOP PHP today, I'd highly recommend you to learn Composer and PSR-4. PSR-4 defines how you should structure a PHP application for class autoloading. Composer implements a PSR-4 autoloader by default.
First you should comply with the namespace standard. The least change to do is to loose the extra "Class1" and "Class2" in your namespace:
<?php
// Class1.php
namespace Models;
/**
* Class1 does things
*/
class Class1 {
public function someMethod() {
// code
}
}
<?php
// Class2.php
namespace Models;
use \Models\Class1;
/**
* Class2 does other things
*/
class Class2 extends Class1 {
public function someMethod() {
// code
}
}
With a nicely structured application folder, namespace structure and a correctly written autoload.psr-4 section in composer.json, composer will help you to generate a class autoloader. Your composer.json would probably look like this:
{
"autoload": {
"psr-4": {
"Model\\": "Model/"
}
}
}
You may now run composer dump-autoload to create the autoloader. Then you can simply add this to your entry script app.php. When things are ready, you may simply add use and new statement anywhere in the application.:
<?php
// app.php
use Models\Class1;
use Models\Class2;
require_once './vendor/autoload.php';
$c1 = new Class1();
$c2 = new Class2();
All includes are handled by the autoloader. Hands free.
Remove the line
include('./Class1.php');
I created a class at Controller folder of Cake project like this:
<?php
class Hi
{
function __construct(){ }
public function hi()
{
echo "hi!";
exit;
}
}
Then in a controller, I tried to include it:
<?php
namespace App\Controller;
use App\Controller\AppController;
include_once "Hi.php";
class MyController extends AppController
{
public function sayHi()
{
$a = new Hi();
$a.hi();
}
}
Here is the error I'm having:
Fatal error: Cannot declare class Hi, because the name is already in use in path\api\src\Controller\Hi.php on line 2
What's going on?
MyController.php and Hi.php are in the same folder. I'm using PHP 7.
Including a file won't make the classes in that file part of the current namespace, as namespaces are a per-file functionality.
http://php.net/...namespaces.importing.php#language.namespaces.importing.scope
Your Hi class will be declared in the global namespace, and your new Hi() will cause PHP to look for it in the current namespace, ie it will look for App\Controller\Hi, which doesn't exist, hence the composer autoloader kicks in, and will map this via a PSR-4 namespace prefix match to src/Controller/Hi.php, which will include the file again, and that's when it happens.
http://www.php-fig.org/psr/psr-4/
Long story short, while using new \Hi() would fix this, you better not include class files manually, or declare them in paths where they do not belong. Instead declare your files and classes in a proper autoloading compatible fashion, that is for example with a proper namespace in a path that matches that namespace, like
namespace App\Utils;
class Hi {
// ...
}
in
src/Utils/Hi.php
I have created this factory class:
namespace ValidatorFactory;
foreach (glob("Types/*.php") as $filename)
{
include $filename;
}
class ValidatorFactory
{
public static function getValidator($betTypeId)
{
switch ($betTypeId)
{
case 1:
return new B();
break;
default:
return null;
}
}
}
Here is my A abstract class definition:
abstract class A
{
abstract function validateSchema($schema);
}
Here is my B class definition:
class B extends A
{
function validateSchema($schema)
{
return true;
}
}
Now I want to use the factory class in some other file in my project, here is how I am doing it:
$obj = ValidatorFactory::getValidator($someId);
I am using Laravel and via composer (and this tutorial) I tried to load the ValidatorFactory class like built in classes of laravel. Here is what I have added to the composer file:
"autoload": {
"classmap": [
...
],
"psr-0": {
"ValidatorFactory": "app/"
}
},
I have run composer update.
My problem is that my ValidatorFactory is not loaded because I am getting this error:
Class 'ValidatorFactory' not found
If I will add the namespace like this:
$obj = ValidatorFactory\ValidatorFactory::getValidator($someId);
I am getting other error, here it is:
Class 'ValidatorFactory\B' not found
So there are 2 problems, first related to larave/composer autoload (of the namespace). The second is related to includes and inheritance (as I suspect) in php.
How can I solve this two issues? Thanks!
Update:
As suggested in the answer, I have added the same namespace for all 3 involved classes A, B and the factory. No class including any other class.
In the class which calls the factory's getValidator function I am doing it like this:
$obj = ValidatorFactory\ValidatorFactory::getValidator($someId);
Still getting the error which says class B is unknown :(
Here is how the updated class B looks like:
namespace ValidatorFactory;
class B extends A
{
function validateSchema($schema)
{
return true;
}
}
The file structure looks like this: factory file located in app/dir1/ , Class A and B located in app/dir1/dir2/
Anything defined in an include is defined in the global namespace, so the abstract class definitions define the \A and \B classes, respectively (and not ValidatorFactory\A or ValidatorFactory\B). In order to use them the way you are, you would need to add a use statement for each of them after they are included.
But why include anything at all? This goes agains the very idea of an autoloader. If you want to declare a class, put it in one of your namespaces and let Laravel and composer do the hard work for you.
Update
return new B();
Try changing that line to:
return new \B();
And that will clear up your second error. As for the first, you declared your Validator factory to live in a namespace:
namespace ValidatorFactory;
Any code that uses that class (which is not in the same namespace) will need to either A) import the class with a use statement, or B) use the Fully-Qualified Namespace whenever referencing it:
use ValidatorFactory\ValidatorFactory;
// ...
$factory = new ValidatorFactory();
Or
$factory = new ValidatorFactory\ValidatorFactory();
Remember, all namespaces are for is to allow you and another developer to name a class exactly the same thing. For instance, perhaps I'm working on some sort of route mapping tool. I may want to define a Route class, because that name fits extremely well with my current problem domain. However, Taylor already beat me to the punch because there already is a Route class. Using a name space I can ensure that I can still name anything I want whatever I want however I want to and there won't be any conflicts with stuff that has already been named or stuff that has yet to be named.
Update 2
Namespaces in projects using composer need to mirror the directory path in which the underlying files are located (this is how the autoloader can find them- it basically looks at the namespace and classname and turns that into a directory path to the file, and appends a .php extension). If you have classes like this:
// File: app/dir1/dir2/A.php
class A{}
// File: app/dir1/dir3/B.php
class B{}
Then A will have to be in the namespace dir1\dir2, and its fully qualified name would be dir1\dir2\A. Similarly, class B would have to be in the namespace dir1\dir3 and its fully qualified name would be dir1\dir3\B.
From our chat discussion, we couldn't figure out why PSR-0 is not working for you. It turns out that PSR-4 configuration works fine. So I summarise here what we did in the discussion to use PSR-4 autoloading.
File structure:
app
|- commands
|- config
|- ...
|- MyValidator
|- MyValidatorFactory.php
|- A.php
|- B.php
|- ...
MyValidatorFactory.php
namespace MyValidator;
class MyValidatorFactory
{
...
return new B();
...
}
B.php
namespace MyValidator;
class B extends A
{
function validateSchema($schema)
{
return true;
}
}
And finally you can setup PSR-4 autoloading in your composer.json:
"autoload": {
...
"psr-4": {
"MyValidator\\": "app/MyValidator"
}
}
Bonus point:
With the psr-4 configuration above, you may also structure your namespaces and classes like this:
app
|- commands
|- config
|- ...
|- MyApp
|- Validators
|- MyValidatorFactory.php
|- A.php
|- B.php
|- ...
And set the psr-4 config to "MyApp\\": "app/MyApp", the autoloader will recognise your classes and use it like below:
new \MyApp\Validators\MyValidatorFactory;
new \MyApp\Validators\A;
new \MyApp\Validators\B;
I'm trying to implement custom exception classes for a zend project.
I use modules and all my classes are under library.
so a filename DuplicateFileException.php which is under
APPLICATION_PATH "/../library/Abra/Exception" contains
class Abra_Exception_FileNotFoundExcpetion extends Exception {}
class Abra_Exception_MissingFileException extends Exception {}
class Abra_Exception_DuplicateFileException extends Exception {}
class Abra_Exception_FileIOException extends Exception {}
so the ErrorController works fine when i only throw Abra_Exception_DuplicateFileException
because there is indeed a file called DuplicateFileException, but the app breaks when i throw any other than that Exception.
I just can't believe that i have to create a file for each of them.
so how to work around it?
thanks for reading.
Proper zend-way would be implementing your own autoloader class. IT will implement autoload method. You can then use Zend_Autoloader autoloader stack to oad your classes. You just need to have some kind of system/logic in your classname->filename mapping.
class Abra_Autoloader
{
public function autoload($className)
{
if (strpos('Abra_Exception', $className) !== false) {
include $someFile; //faster
}
}
}
//anywhere in bootstrap (preferably in some autoloading section of yours)
// autoloader will load only classes starting with "abra"
$autoloader = Zend_Loader_Autoloader::getInstance();
$autoloader->setFallbackAutoloader(true);
$autoloader->pushAutoloader(array('Abra_Autoloader ', 'autoload'), 'Abra');
Please note that at least teh autoloader class should be Zend_Loader-loadable :)
The Zend autoloader works by mapping requested class names to filesystem paths so you can't make it load a file for a class where the filename does not match.
If you really want to persist down this path, I'd just include the file in your Bootstrap class, eg
protected function _initRequires()
{
require_once 'Abra/Exception/DuplicateFileException.php';
// assuming your "library" folder is on the include path
}
I'm trying to extend my controllers with a global base controller as such:
class BaseController extends Zend_Controller_Action {
// common controller actions
public function listAction() {
// do stuff
}
}
class IndexController extends BaseController {
// index controller specific actions
}
class LoginController extends BaseController {
// login controller specific actions
}
But I get this error:
PHP Fatal error: Class 'BaseController' not found in /var/www/Zend/project/application/controllers/IndexController.php on line 3
Any ideas on how to get Zend to "see" this controller?
Autoloader
Setup the autoloader and register your library which should be besides the Zend library with the autoloader like so (in your bootstrap.php after setting the include path):
//AutoLoad loads classes automatically if they are used
require_once 'Zend/Loader/Autoloader.php';
$loader = Zend_Loader_Autoloader::getInstance();
$loader->registerNamespace('Mylibrary_');
Zend naming conventions
Then you should rename your BaseController as follows
/Zend (folder)
/Mylibrary (folder)
/Controller (folder)
Action.php <-- this is your basecontroller file
which contains:
class Mylibrary_Controller_Action extends Zend_Controller_Action
{
}
and your normal controllers in the controller folder:
class IndexController extends Mylibrary_Controller_Action
{
}
so basically when you want to extend the framework you keep a parallel structure in your own library.
I would separate it into your own library, i.e. create the file library/YourApp/Controller/Action.php, and consequently name it YourApp_Controller_Action extends Zend_Controller_Action. From there you could place controllers where they should be and let them extend YourApp_Controller_Action in favor of Zend_Controller_Action.
To find the file you should rely on the autoloader to look not just inside of library/Zend, but also in library/YourApp. I.e. look for the set_include_path in your bootstrap.
With this technique you should keep in mind that your custom "basecontroller" might get bloated with methods that not all of your controllers needs to inherit.
the quick solution that does not take advantage of the autoloader functionality is to
require_once '/path/to/BaseController.php' in the index-controller file.
If you have set-up autocontroller, then it can not find it, so you should consider checking what's wrong. Try the previous approach and inform on results.
Even more quicker solution (and conceptually more correct) is NOT to create base controllers at all:)
You have common action? Use action helpers. You have some functionality that must be autorun? Use controller plugins.
By design ZF controllers were made as flexible as possible, and limiting yourself by inheritance (and coupling it brings) is just not the best possible strategy.