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
Related
EDIT:
Yes the problem was using \ at the beginning of the use statement. As M1ke pointed out, use goes from the root element.
Original post
I think is a PHP question but it may be Drupal.
I'm working on a headless Drupal project where is using a class (which I call Entity Model) that uses a Drupal class called EntityFieldQuery.
Before a create or use this class I bootstrap Drupal using:
require_once DRUPAL_ROOT.'/includes/bootstrap.inc';
drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);
The entity model class is in the Models names space like so:
namespace Models;
use \EntityFieldQuery;
class EntityModel
{
.....
$query = new EntityFieldQuery();
$query->doSomething();
......
}
The EntityFieldQuery is found perfectly as I use the "\" because this class is out of the Models namespace.
The problem is when this class is created is uses other classes that don't use any namespace, and I have the following error:
class Models\InsertQuery not found in ....
Here is the class used by EntityFieldQuery that uses InsertQuery
class InsertQuery_mysql extends InsertQuery ...
I don't understand why InsertQuery_mysql is found but InsertQuery
I ended up adding a "\" in InsertQuery to fix the problem like so:
class InsertQuery_mysql extends \InsertQuery ...
Actually this class in a php file called query.inc that contains two defitinion classes (in the same file, I don't know this is a a problem too)
class InsertQuery_mysql extends InsertQuery
....
class TruncateQuery_mysql extends TruncateQuery
I thought that if I use "new \ClassName()" the "default namespace" inside this class would be "\" too and not the first called class's namespace.
I don't like to modify 3rd party libraries, is any way to avoid this? I guess is a architecture problem rather than a lack of definition if someone has a better idea, I appreciate.
Thanks!
EDIT2: Adding more info...
In order of execution.
index.php:
require_once 'vendor/autoload.php';
require_once DRUPAL_ROOT.'/includes/bootstrap.inc';
drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);
...
app/SiteController.php:
use Models\Campaign;
class SiteController {
...
$campaing = new Campaign();
...
app/Models/Campaing.php:
namespace Models;
class Campaign extends EntityModel {
...
app/Models/EntityModel.php:
namespace Models;
use \EntityFieldQuery; //<-- this should go without \ as I say in EDIT section
class EntityModel {
...
public function getAll() {
$query = new EntityFieldQuery(); //<--throwed Models\InsertQuery not found. It must have \ at the beginning of the class name.
To answer the base question (and pending further code) PHP namespaces are set by whichever namespace is declared in the file.
// Bar.php
namespace Foo;
class Bar {}
// some other file
use Foo\Bar;
$test = new Bar(); //works
// different file
namespace Foo;
$test = new Bar(); // works
// another file
require 'Bar.php';
// won't work because we are not in namespace "Foo"
$test = new Bar();
In your specific case it the use \EntityLoader should be use EntityLoader because you're exiting the namespace you want to be inside.
on index.php I have below code
require 'Bootstrap.php';
require 'Variables.php';
function __autoload($class){
$class = str_replace('Control\\', '', $class);
require_once 'class/'.$class.'.php';
}
$bootstratp = new Control\Bootstrap();
on Bootstrap.php
namespace Control;
class Bootstrap{
function __construct(){
Constructor::load_html();
self::same_namespace_different_class();
}
static function same_namespace_different_class(){
Variables::get_values();
}
}
in class/Constructor.php
class Constructor{
static function load_html(){
echo 'html_loaded';
}
static function load_variables(){
echo 'load variables';
}
}
and on Variables.php
namespace Control;
class Variables{
static function get_values(){
Constructor::load_variables();
}
}
Assume, In total I have 4 PHP files including 3 Class files of 2 different namespaces. I also have a __autoload function on index.php that will call classes from 'class' folder but my 'Control' namespace files are in root folder.
When I echo the class name in __autoload i get the all the class names starting with 'Control\' even when I am calling a class from global namespace.
I am getting below error
Warning: require_once(class/Variables.php): failed to open stream: No such file or directory in _____________ on line 10
what is wrong with my code??
When I echo the class name in __autoload i get the all the class names starting with 'Control\' even when I am calling a class from global namespace.
This is because in Bootstrap.php all the code is in Control namespace (namespace Control). So when you use:
Variables::get_values();
you call
\Control\Variables::get_values();
if you want to use Variables from global namespace you should use here:
\Variables::get_values();
Of course, the same happens for in Variables.php file:
Constructor::load_variables();
As Constructor is defined in global namespace (in class/Constructor.php there is no namespace used), you should access it here using:
\Constructor::load_variables();
If it's still unclear you could also look at this question about namespaces in PHP.
You should also notice that using __autoload is not recommended. You should use spl_autoload_register() now. Documentation about autoloading
I have been looking into name spaces recently. I am creating an MVC framework and want to try to move towards PHP 5.3+ features.
Lets say I define a namespace, call it \Controller.
I then want to include a file which has the class of Home.
namespace Controller;
include "class.home.php";
The file contents:
class.home.php:
class Home {
public function hello() {
}
}
In this example, will Home be a part of the Controller namespace? or part of the global namespace?
I want to be able to access Home like new \Controller\Home(); Will the code above work like that?
The namespace of a class depends on the namespace it was declared in, not in which it was included. If the latter was the case, it'd be impossible to clearly know what namespace something will be in.
If you did not write namespace Foo\Bar\Baz; at the top of the file in which you declare the class, the class is in the global namespace, always.
In your case Home will not be part of the Controller namespace, because you need to define the namespace inside of class.home.php like:
namespace Controller;
class Home {
public function hello() {
}
}
And than you can:
namespace Controller;
include "class.home.php";
new \Controller\Home();
I have a question about namespaces in PHP.
this code doesn't work :
<?php
namespace My\Functions\Printing;
class A {
public function __construct() {
echo __NAMESPACE__;
}
}
namespace My;
use My\Functions\Printing\A as A;
$obj=new namespace\A();
But this one work :
<?php
namespace My\Functions\Printing;
class A {
public function __construct() {
echo __NAMESPACE__;
}
}
namespace My;
use My\Functions\Printing\A as A;
$obj=new A();
I would like to get more information about the behavior of namespaces importation.
Why an imported class can't be accessible in the namespace where it is imported?
Probably you have a confused idea of using 'use'.
The keyword 'namespace' refers to the current namespace
namespace My\Functions\Printing;
class A {
public function __construct() {
echo __NAMESPACE__;
}
}
namespace My;
use My\Functions\Printing\A;
use My\Functions\Printing\A as myAlias;
$obj=new namespace\A(); // instance of \My\A (doesn't exist)
$obj2=new A(); // instance of \My\Functions\Printing\A
$obj3=new myAlias(); // instance of \My\Functions\Printing\A
As usual, see the documentation for complete details: php doc
I'm not sure but I think problem is in using namespace keyword.
http://www.php.net/manual/pl/language.namespaces.nsconstants.php
In first example you are in My namespace so namespace\A() == My\My\Functions\Printing\A()
My\Functions\Printing namespace look like
-- My\Functions\Printing
A
"My" namespace before importation look like:
-- My
"My" namespace after importation should look like (i thinks)
-- My
A
So why i can't acces My\A ?
I think the structure of namespace it's not changed an PHP compiler check in the "namespace imported area" before the "namespace structure".
Documentation specify namespaces look like filesystem, it's false.
If an importation of an other class is as "create a symbolic link" i must be able to acced it from the current namespace.
We can acced a symbolic link from the directory where it was created or from the absolute path but it's not possible to acced the imported class
with its new path. (\My\A)
Why ?
I have been searching websites to try and get a handle on using PHP namespaces, but they all seem quite vague but what they're trying to do is easy to understand!
My question is: I have a file called people.php and in it is defined class called people. If I create another file called managers.php in the same folder can I define a class again called people which extends the original people class but in the namespace of managers, if so do I have to 'include' the original people.php and if so do I put the include after the writing: namespace managers?
Namespaces are a way to group your related classes in packages. What you describe could best be put under a single namespace like
<?php // people.php
namespace com\example\johnslibrary\people;
abstract class People {
}
and then
<?php // manager.php
namespace com\example\johnslibrary\people;
require_once 'path/to/People.php'; // can better use autoloading though
class Manager extends People {
}
because a Manager is a subclass of People, so there is not much of a reason to put them into their own namespace. They are specialized People.
If you want to Managers to be in their own namespace, you can do so, but have to use the fully qualified name when using the extends keyword, e.g.
<?php // manager.php
namespace com\example\johnslibrary\managers;
require_once 'path/to/People.php';
class Manager extends \com\example\johnslibrary\people\People {
}
or import the People class first
<?php // manager.php
namespace com\example\johnslibrary\managers;
use com\example\johnslibrary\People as People;
require_once 'path/to/People.php';
class Manager extends People {
}
See the PHP Manual on Namespaces for extensive documentation.
// people.php
<?php
namespace People;
class People {}
// managers.php
<?php
namespace Managers;
require_once __DIR__.'/people.php';
class People extends \People\People {}
I have old PHP Class and i need to use it in new PHP file as for example:index.php has to use iClass.php. But before using the OLD iClass.php i have to modify it as below, so that i can use it in index.php.
iClass.php:
namespace ic;
class iClass {
public static function callMeFromClass() {
echo 'OK - you have called me!';
exit;
}
}
index.php
namespace inex;
require_once 'iClass.php';
use ic\iClass;
iClass::callMeFromClass();