How would I go about autoloading a class after having used the use keyword?
e.g.
use Code\Store\Core\Store;
$_STORE = Factory::Get( "Store" );
My autoloader goes looking for Store.php when I want it to go looking for /Code/Store/Core/Store.php
Is there a way to expand a namespace after having used use? Or autoload it during the use definition? Or is my only option to use the full namespace when getting a class from the factory?
Related
I am trying to use Azure storage for php, the setup steps are to include the namespace, include composer autoload and then use the azure classes, so I have the following. However further down I use the class Microgrid and it's not found because of the namespace, it is in a different directory. How can I use other classes that aren't part of that namespace? Also, what's the correct way to specify your namespace path? It's in a different directory relative to the page this is for and the one I am using is not at the root, should I start at the root?
namespace MicrosoftAzure\Storage;
use \MicrosoftAzure\Storage\Common\ServicesBuilder;
use \MicrosoftAzure\Storage\Blob\Models\CreateContainerOptions;
use \MicrosoftAzure\Storage\Blob\Models\PublicAccessType;
use \MicrosoftAzure\Storage\Common\ServiceException;
require_once '/var/www/html/vendor/autoload.php';
$action = MicroGrid::GetParameter('action');
ClassNames are considered relative to the current namespace unless they start with a \
This means that inside the MicrosoftAzure\Storage namespace you can use the relative namespace for class.
If you want to call a class from a different namespace you should call fully-qualified name for it like
$action = \MicrosoftAzure\WhereEver\MicroGrid::GetParameter('action');
or use the name space or unique class with fully-qualified name
use \MicrosoftAzure\WhereEver;
or
use \MicrosoftAzure\WhereEver\MicroGrid;
then:
$action = MicroGrid::GetParameter('action');
Edited to make it clear
namespaces allow us to avoid naming collisions and to alias long
names caused by avoiding naming collisions.
it depends to your autoloader for a simple example I create a new project and make this autoloader in the index.php located at root directory
function __autoload($className){
//if it's a full name with windows style slashes correct the path
$file_name = str_replace('\\', '/', $className);
require_once("vender/src/".$file_name.".php");
}
when I call $date = new \App\Utility\Date(); autoloader will require this file:
verdor/src/App/Utility/Date.php
and in Date.php I used this name space namespace App\Utility;
PHP does not provides a class autoloader out of the box.
There are many autoloaders for PHP, and the most common autoloader standard is the PSR-4, used by many frameworks and applications.
If you are not using an autoloader, you should require every class file (and recursive dependencies) before using it.
Azure uses Composer Autoloader and PSR-4.
You should use Composer Autoloader on your project, then import your class from the right namespace (you are not importing it on your example code)
A namespace basically groups your classes together. You can use something outside your namespace by explicitly using it e.g.
namespace App;
use Illuminate\Database\Eloquent\Model;
In this case I'm 'grouping' this and other classes in a namespace called 'App' but I want to use 'Model' provided by Eloquent (the Eloquent class having a namespace of 'Illuminate\Database\Eloquent') in this class.
If 'Microgrid' is not part of your current namespace, you'll need to explicitly add its namespace in your 'use' statements.
I would like to Use the same class Helper, located at App\Helpers\Helper, in two different files within the same namespace.
For example:
Class A:
<?php
namespace App\Services;
Use Helper;
class A {...}
Class B:
<?php
namespace App\Services;
Use Helper;
class B {...}
However, this is not allowed. The error is:
Cannot use App\Helpers\Helper as Helper because the name is already in use
I could rename the Helper class in my second file and say Use Helper as SomethingElse, but this seems like a messy solution especially if I want to use this Helper in many more than two classes.
Is there a workaround for this?
You most probably already have an included class that goes by that name, the likely problem is that you have a class by that name in another namespace (and said class has been included). You can use both classes (from different namespaces with the same name) by aliasing or using fully qualified names of the classes.
Read this properly.
I'm just wrapping my head around PHP namespaces and autoloading with composer. I have a question about the following code:
namespace APP\Controllers;
use APP;
use APP\Interfaces;
use APP\Lib;
class PageController
extends Lib\ActionController
implements Interfaces\ControllerInterface
{
//stuff
}
Why do I have to prepend the extends class with the sub-space with 'Lib\' when I already use the line 'use APP\Lib;'? Same goes for the interface. When I don't prepend I get an autoload error. I'm using composer to autoload and have this in my composer.json:
"autoload": {
"psr-4": {
"APP": "app/"
}
}
In app/ I have subfolders Lib, Interfaces and Controllers like so:
/app
/Controllers
/Interfaces
/Lib
I noticed that in other devs code they don't have to do this. I'm confused as to what I am doing wrong.
Thanks for the help.
You are including three namespaces:
use APP;
use APP\Interfaces;
use APP\Lib;
Now if you say just:
extends ActionController
PHP would not know if it is:
APP\ActionController or
APP\Interfaces\ActionController or
APP\Lib\ActionController
If you still wanted to extend it without Lib subspace you would need to do:
use APP\Lib\ActionController; first
use is only there to alias namespaces or class names to shorter names. It's there to avoid having to repeatedly address all classes by their fully qualified name all the time:
$a = new \Foo\Bar\Baz\Quurx();
$b = new \Foo\Bar\Baz\Quurx();
// shorter:
use Foo\Bar\Baz\Quurx;
$a = new Quurx();
$b = new Quurx();
use Foo\Bar is shorthand for use Foo\Bar as Bar. So, you're creating an alias Bar which really resolves to the full name \Foo\Bar. Since APP\Interfaces doesn't resolve to any particular interface in your case, just using implements Interfaces wouldn't mean anything. And if you just used implements ControllerInterface, it would be ambiguous which namespace that resolves to. \APP\Controllers\ControllerInterface? \APP\ControllerInterface? \APP\Lib\ControllerInterface? It's just not clear and cannot be resolved automatically.
So, what you're doing is you're shortening APP\Interfaces to just Interfaces, and then refer to APP\Interfaces\ControllerInterface by just using the shorter Interfaces\ControllerInterface. You could be doing this to make it even shorter:
use APP\Interfaces\ControllerInterface;
.. implements ControllerInterface ..
What I want to do is to use different namespaces in a controller. I have a tree scheme like this:
app/
app/controllers/
app/modules/
app/modules/modulename/
app/modules/modulename/controllers/
app/modules/modulename/controllers/modulecontroller.php
app/modules/modulename/models/
app/modules/modulename/models/modulemodel.php
What I want to do is to call a model from a controller in app/controllers/ folder. Therefore I am supposed to add namespace as follows:
use App\Modules\Facebook\Controllers\Facebook;
The problem is that when I add a namespace and use App::() function at the sametime, I get the following error:
Class 'App\Modules\Modulename\Controllers\App' not found
I think it is looking the App::() function in module folder. How can I solve this problem?
if you use App inside your App\Modules\Facebook\Controllers namespace, it will be interpreted as App\Modules\Facebook\Controllers\Facebook\App class.
since you don't want to have the previous namespace, you use a \ before App like:
\App::()
or put a use statement of top the class like use App;
You probably are creating an unusual namspace scheme. It appears you are namespacing every class from your module differently. You should namespace your code within your module only, like so:
// Adding Onur to the namespace prevents any future namespace collisions.
<?php namespace Onur\Facebook;
After creating your namespace you should add all classes that are outside of your namespace that you want to use as followed.
use Eloquent, Input, Validate, Etc;
This prevents you from adding a \ in front of every class instance, making your code hard maintain and prone to errors. It also gives you a good overview on all the classes you are using in the current class.
if you say
use App\Modules\Facebook\Controllers\Facebook;
then you are supposed to use Facebook instead of App... Or don´t I understand your problem correctly?
if you say
use App\Modules\Facebook\Controllers\Facebook as FacebookController;
the you can use FacebookController in your file
if you need Access to the root App, you need to to root it using a leading \
\App::make()
a quick (maybe stupid) question.
I'm using a namespace for my controllers, like so:
namespace Members;
use DB;
use Input;
use PerformanceReport;
use Redirect;
class AdminController extends MembersController {
And as expected, I have to provide use statements for the Laravel classes I wish to use.
From what I've understood, the composer autoloader prevents this from being necessary if used correctly.
So my question being, is it possible to configure the autoloader to suit my needs, and if so, how would I go by doing this?
Your question is connected with the way PHP namespaces work, not with composer's autoloader.
If your class is in namespace Controllers; and you'd write Redirect::to('/') php would assume that the class you're referring to is in the current declared namespace (in that case Controllers/Redirect). You can either write \Redirect::to('/') or put a use Redirect statement on top like you did.
Composer's autoload just maps namespaces to their file directory (see vendor/composer/autoload_classmap.php for how it maps it).
If you want to dive more into composer's autoloading, i'd recommend read up on PSR-0 and PSR-4.