I want to make a PHP class, lets say Myclass.php. Now inside that class I want to define just the class itself and some instance variables. But all the methods must come from a Myclass_methods.php file. Can I just include that file into the class body?
I have good reasons why I want to seperate this. In short, I'll have a backend in which I can change the business logic of a class, while all other things must remain untouched. The system maintains all the ORM and other stuff for me.
But if this is a bad idea, it might be better to re-generate the whole class file after editing the business logic (so, the user-defined methods in this case).
Performance question: If during one request Myclass.php is included just once, actually that Myclass_methods.php should also be included just once. Might be wrong. Experts?
No. You cannot include files in the class body.
In a file defining a class, you may only include files in a method body or outside the class body.
From your description I take you want this:
<?php // MyClass.php
class MyClass
{
protected $_prop;
include 'myclass-methods.php';
}
<?php // myclass-methods.php
public function myMethod()
{
$this->$_prop = 1;
}
Running this code will result in
Parse error: syntax error, unexpected T_INCLUDE, expecting T_FUNCTION
What is possible though is this
<?php // MyClass.php
class MyClass
{
protected $_prop;
public function __construct() // or any other method
{
include 'some-functions.php';
foo($b); // echoes 'a';
}
}
<?php // some-functions.php
$b = 'a';
function foo($str)
{
echo $str;
}
Doing it this way, will import the contents of the include file into the method scope, not the class scope. You may include functions and variables in the include file, but not methods. You could but should not put entire scripts into it as well and change what the method does, e.g.
<?php // MyClass.php
// ...
public function __construct($someCondition)
{
// No No Code here
include ($someCondition === 'whatever') ? 'whatever.php' : 'default.php';
}
// ...
<?php // whatever.php
echo 'whatever';
<?php // default.php
echo 'foo';
However, patching the class this way to exhibit different behavior is not how you should do it in OOP. It's just plain wrong and should make your eyes bleed.
Since you want to dynamically change behavior, extending the class is also not a good option (see below why). What you really will want to do is write an interface and make your class use objects implementing this interface, thus making sure the appropriate methods are available. This is called a Strategy Pattern and works like this:
<?php // Meowing.php
interface Meowing
{
public function meow();
}
Now you got the contract that all Meowing Behaviors must obey, namely having a meow method. Next define a Meowing Behavior:
<?php // RegularMeow.php
class RegularMeow implements Meowing
{
public function meow()
{
return 'meow';
}
}
Now to use it, use:
<?php // Cat.php
class Cat
{
protected $_meowing;
public function setMeowing(Meowing $meowing)
{
$this->_meowing = $meowing;
}
public function meow()
{
$this->_meowing->meow()
}
}
By adding the Meowing TypeHint to setMeowing, you make sure that the passed param implements the Meowing interface. Let's define another Meowing Behavior:
<?php // LolkatMeow.php
class LolkatMeow implements Meowing
{
public function meow()
{
return 'lolz xD';
}
}
Now, you can easily interchange behaviors like this:
<?php
require_once 'Meowing.php';
require_once 'RegularMeow.php';
require_once 'LolkatMeow.php';
require_once 'Cat.php';
$cat = new Cat;
$cat->setMeowing(new RegularMeow);
echo $cat->meow; // outputs 'meow';
// now to change the behavior
$cat->setMeowing(new LolkatMeow);
echo $cat->meow; // outputs 'lolz xD';
While you also could have solved the above with inheritance by defining an abstract BaseCat and meow method and then deriving concrete RegularCat and Lolkat classes from that, you have to consider what you want to achieve. If your cats will never change the way they meow, go ahead and use inheritance, but if your RegularCat and Lolkat is supposed to be able to do arbitrary meows, then use the Strategy pattern.
For more design patterns in PHP, check these resources:
http://www.php.net/manual/en/language.oop5.patterns.php
http://www.ibm.com/developerworks/library/os-php-designptrns/
http://www.fluffycat.com/PHP-Design-Patterns/
http://sourcemaking.com/design_patterns
Might it not be an idea to create the core class with the relevant base functionality and then extend this with the required methods - it seems like a more logical approach.
I'll start by saying I'm not too clear why this problem is not best solved using a base class containing the methods, subclasses containing the data, and dynamic class loading. I'll assume you have a good reason.
Once your provider supports PHP 5.4 you can do what you want using traits.
Code File:
if ($pet === 'dog') include 'dog.php';
elseif ($pet === 'cat') include 'cat.php';
else die('Unknown pet');
class Pet {
use PetSounds;
}
$myPet = new Pet();
$myPet->speak();
File cat.php
trait PetSounds {
function speak() { echo 'meow'; }
}
File dog.php
trait PetSounds {
function speak() { echo 'woof'; }
}
You could make this even cleaner by naming both include files the same, putting them in different subdirectories, and using set_include_path() or defining an __autoload() function to select between them. Like I said though, this same problem could be solved better using inheritance. If you have a multiple-inheritance type problem though, if for instance you have four kinds of pets with five kinds of colors with three hair types and you need a different combination of methods for each of the 60 different classes, this is the right solution.
5.4 is currently just a Release Candidate (as of 2/24/2012) and even once released most hosts will not support it for many months - mine took 18 months after 5.3 was released before they would support it. Until then you must write entirely separate and complete class files. You can however format your classes with an eventual change to traits in mind.
Right now you can partially get what you want using magic methods and have an easy upgrade to traits when they are available.
Code File:
if ($pet === 'dog') include 'dog.php';
elseif ($pet === 'cat') include 'cat.php';
else die('Unknown pet');
class Pet {
public function __call($name, array $arguments)
{
array_unshift($arguments, $this);
return call_user_func_array("TraitFunc_$name", $arguments);
}
}
$myPet = new Pet();
$myPet->speak();
File cat.php
function TraitFunc_speak(Pet $that) { echo 'meow'; }
File dog.php
function TraitFunc_speak(Pet $that) { echo 'woof'; }
You are limited however in that your functions can not access private and protected class properties and methods and you can not use this method to provide magic methods such as __get(). Traits will solve both of those limitations.
What about using traits for this? Would that be an acceptable option? This is something I am currently experimenting with and it seems to work quite while.
A simplified version of what I am doing is basically like this. I have an application with shared core files and multiple projects. Within those projects i have modules. I want to have functions that are available for the entire project on a core level but only for that specific project.
My project controller
if(is_file(PROJECT_PATH.'/project_extensions.trait.php')){
// additional functions for this specific project
require_once(PROJECT_PATH.'/project_extensions.trait.php');
}else{
// no additional functions
trait Extensions{};
}
Class Project{
USE Extensions;
// default functions shared between all projects
function shared_stuff(){
}
}
Extensions file
trait Extensions{
// project-specific extensions
function this_project_only(){
echo 'Project Only';
}
}
Module file in the project
class MyModule extends Modules{ // modules extends projects in a different class not relevant here
function do_something(){
echo $this->project_only();
}
}
Since PHP5.4 release you can create dynamic objects like this: https://github.com/ptrofimov/jslikeobject
But this is scarcely the best practice.
Reviving an old question but this is a fairly simple solution. Do you need the common function calls to be exclusive to your class? If not, simply include your common function file(s) within the same scope as your class. You will need to create methods in your class but they will only need to call the common function. Here's a simple SOAP server example:
<?php
include 'post_function.php';
$server = new SoapServer( null, array('uri' => "http://localhost/") );
$server->setClass( 'postsoapclass' );
$server->handle();
class postsoapclass
{
public function animalNoise( $animal )
{
return get_animal_noise($animal);
}
}
?>
post_function.php
<?php
function get_animal_noise($animal)
{
if(strtolower(trim($animal)) == 'pig')
{
return 'Oink';
}
else
{
return 'This animal is mute';
}
}
?>
I have had to do what you are describing in cases where I maintain a free version and a premium version of the same software. Because, as #Gordon noted, you cannot do exactly this:
class SomeClass {
premium_file = "premium.php";
if (file_exists($premium_file)) {
require($premium_file);
}
Instead I do this:
premium_file = "premium.php";
if (file_exists($premium_file)) {
require($premium_file);
}
class SomeClass {
...
For functions you want to reference, create class methods in the main class, and call the included file's method, passing the $this pointer as a parameter. So that I can tell at a glance where functions are, I will prefix the name of the included functions as shown below:
class SomeClass {
...
// Premium functions
public function showlist() {
premium_showlist($this);
}
You can include or require before declaring your class like below:
require 'path-to-file';
class myClass{
function show($uid){
}
}
The answer is yes, for example:
Into class construct, pass to the function (that's into the included file) values as params:
$this->wpd = $this->wpdopt = 'something';
include_once('/common/functions_common.php');
$this->wpdb = wpquery($sql='', $mode='', $this->wpd);
Into the included functions_common.php file:
function wpquery($sql, $mode, $wdp)
{
if(!empty($wdp))
{ return true; } else { return false; }
}
Into class methods:
$sql = "UPDATE ..... SET ... WHERE LOWER(user_email) = . ...";
$this->wpdb = wpquery($sql,'update',$this->wpd);
OR
$retval_var = $this->wpdb = wpquery($sql,'update',$this->wpd);
OR even
$this->var = $this->wpdb = wpquery($sql,'update',$this->wpd);
Cheers to all the lovely and cool people
I came across this recently, and came up with a solution, that helped in my case. I wanted many functions in a class, but the class became bloated, so wanted to separate out the class functions into groups for readability. It took a little time to accomplish, but since the functions of the class didn't rely (much) on $this, I removed "$this" from the class functions and created several helper files to include those functions. When $this was necessary, I could nevertheless move the function into a helper file, by passing $this to the function, adding public set/get functions where necessary. It's a hack, but it's sure to help someone
class myClass
{
var x;
function myClass()
{
$this->x = 0;
}
function myFunc1Group1()
{
$x = $this->x;
$x++;
$this->x = $x;
}
function myFunc2Group1(){}
function myFunc1Group2(){}
function myFunc2Group2(){}
}
can be worked around to
class myClass
{
var x;
function myClass()
{
$this->x = 0;
}
function doSomething()
{
// not called on $this but takes $this as a parameter
myFunc1Group1($this);
}
}
and helper function set 1
function myFunc1Group1($THIS_OBJECT)
{
$x = $THIS_OBJECT->getX();
$x++;
$THIS_OBJECT->setX($x);
}
function myFunc2Group1($THIS_OBJECT){}
and helper function set 2, etc.
Probably not the best route in all cases, but helped me out a lot. Basically the class functions were only to construct and delegate, and the calculations were put into helpers.
I use PHP 7.1.0.
Let's say we have a trait, we use it inside a class and rename the imported method:
trait T
{
public function A() {
echo ".";
}
}
class C
{
use T {
A as B;
}
}
$c = new C();
$c->B();
$c->A(); // Why does it work?
Why does PHP still allow me to use old method name (A in this case)?
It's really a pain because in more complex examples you cannot rely on method renaming - and thus you can unexpectedly receive "incompatible declarations" error:
class BaseSrc
{
}
trait BaseTrait
{
public function init(BaseSrc $baseSrc)
{
echo "Init Base";
}
}
class Base
{
use BaseTrait {
BaseTrait::init as initBase;
}
}
$base = new Base();
$base->initBase(new BaseSrc());
$base->init(new BaseSrc()); // WHY DOES IT WORK?????
class MainSrc extends BaseSrc
{
}
trait MainTrait
{
use BaseTrait {
BaseTrait::init as initBase;
}
public function init(MainSrc $mainSrc)
{
$this->initBase($mainSrc);
echo "Init Main";
}
}
// Warning: Declaration of MainTrait::init(MainSrc $mainSrc) should be compatible with Base::init(BaseSrc $baseSrc)
class Main extends Base
{
use MainTrait;
}
I think, this code should work. Since I renamed init() into initBase() in the Base class AND did the same renaming when using BaseTrait inside MainTrait, I expect that this method (BaseTrait::init()) will not conflict with MainTrait::init(). In fact, PHP says that I have incompatible declarations. The reason behind it is that renaming init as initBase does not work - method init is still there, in my Base class!
Is there any way how to solve this problem without renaming BaseTrait::init() into something like BaseTrait::initBase() from the very beginning (not just in the use statement)?
Should I consider this as a PHP bug and report it? Is there anything reasonable behind this behaviour?
As mentioned in the comments and for completeness; From the PHP manual section on Traits:
The Aliased_Talker makes use of the as operator to be able to use
B's bigTalk implementation under an additional alias talk.
And then:
The as operator can be used to add an alias to one of the methods.
Note the as operator does not rename the method and it does not affect
any other method either.
So as adds an alias but does not replace or affect the original method in any way. This is the expected behavior.
I can not understand why php gives me an error
"Fatal error: Cannot declare class rex\builder\RexBuilder, because the
name is already in use in /var/www/site2.dev/App/rex/RexBuilder.php on
line 12"
RexBuilder static class, and it is called only 1 time.
I did a search on the project, no longer classes with the same name.
<?php
namespace rex\builder;
require_once 'Router.php';
use rex\router\Router;
error_reporting(E_ALL);
ini_set('display_errors', 1);
class RexBuilder {
public static function collector($array) {
$router = new Router();
foreach ($array as $key => $val) {
$router->get($val->getMethod(), $val->getInterfaces(), $val->getHandler());
}
$router->init();
}
}
?>
Call the class in index.php
RexBuilder::collector(array(
new BuildModel('POST', '/api/v1/user/register', new \api\register\Registration()),
new BuildModel('POST', '/api/v1/user/login', new \api\login\Login())));
More This class is not used
The error is thrown because of the use rex\router\Router; duplicate classes.
When you are writing use namespace.. it means you can go directly to that namespace like it is your current namespace
Lets take a look at the next code:
We'll create a file and declare that it belongs to namespace classes\a
//file: a.php
<?php
namespace classes\a;
class A{
}
now lets create another file b.php (and declare it belongs to namespace classes\b but it means nothing for the example)
namespace classes\b;
require_once "a.php";
use classes\a; //Notice that I'm using this namespace, it means I can use it directly
class A{
}
Generates the error
Fatal error: Cannot declare class classes\b\A because the name is already in use in
We have to solutions possible:
First: remove the use tag and write the namespace directly
class A{
function __constructor(){
$instance = new classes\a\A();
}
}
Second, give it alias
use classes\a as out_a;
class A{
function __constructor(){
$instance = new out_a\A();
}
}
For your code, just remove the use or give it an alias.
The problem is certainly because you include the RexBuilder.php file two times instead of one.
If you call the file by this way : include('RexBuilder.php'); or this way require('RexBuilder.php'); please change it by include_once('RexBuilder.php'); or require_once('RexBuilder.php'); which only allows ONE call of the file.
I'm trying to run this code on the same file:
namespace Foo1\Bar\SubBar;
class SubBarClass {
public function __construct() {
echo 'From Foo1';
}
}
namespace Foo2\Bar\SubBar;
class SubBarClass {
public function __construct() {
echo 'From Foo2';
}
}
use Foo1\Bar\SubBar;
$foo1 = new SubBarClass;
use Foo2\Bar\SubBar;
$foo2 = new SubBarClass;
The ideia is to change namespaces and echo the related value.
But it's returning the following error:
( ! ) Fatal error: Cannot use Foo2\Bar\SubBar as SubBar because the name is already in use in C:\wamp\www\xxx\namespaces.php on line 30
Line 30: use Foo2\Bar\SubBar;
How can I interchange namespaces on the same file?
Thks!
use keyword is used to import that namespace to be accessed in your current file scope. It does not act as a namespace "instance constructor".
You're current under Foo2\Bar\SubBar namespace. Like a directory of classes, while you're here, you should access other namespaces from the root (\):
$foo2 = new SubBarClass;
$foo1 = new \Foo1\Bar\SubBar\SubBarClass;
There is no need to use use for those namespaces (although you can, specially when they share parent namespaces), they are already declared in the same file you're using them.
For more information about this, consider reading the manual, where it describes using multiple namespaces in the same file.
This happens because the last defined namespace is the one currently active.
So, when I type:
use Foo1\Bar\SubBar;
I'm still on the last defined namespace: Foo2\Bar\SubBar.
Hence, when I type:
use Foo2\Bar\SubBar;
I'm trying to use the currently active namespace. That's why the Fatal error is returned.
On possible solution is:
namespace Foo1\Bar\SubBar;
class SubBarClass {
public function __construct() {
echo 'From Foo1';
}
}
namespace Foo2\Bar\SubBar;
class SubBarClass {
public function __construct() {
echo 'From Foo2';
}
}
use Foo1\Bar\SubBar;
$foo1 = new SubBar\SubBarClass;
echo '<br>';
$foo2 = new SubBarClass;
Cheers!
I have parent class Color and children, ColorRGBA and ColorHSLA. In class Color I want to use a static functions from these children, but I got error "Class 'Color' not found." Here is the same problem http://forums.codeguru.com/showthread.php?t=469995 but class Color; doesn't seem to work in PHP.
Color.php:
include_once 'ColorRGBA.php';
include_once 'ColorHSLA.php';
class Color{
public static function isValid(&$tokens, $i) {
return ColorRGBA::isValid($tokens, $i) || ColorHSLA::isValid($tokens, $i);
}
}
ColorHLSA.php and similarly ColorRGBA.php
include_once 'Color.php';
class ColorRGBA extends Color {
public static function isValid(&$t, &$i) {
...
}
}
How should I rebuild my class hierarchy or include directives? Or is there any other option how to make my code work?
Yes in PHP there are no "forward declarations" like in C++. That's why class Color; is invalid in PHP.
Now why do you get "Class 'Color' not found."? The problem is that, this line
class ColorRGBA extends Color
gets executed before that line:
class Color {
So Color is indeed not defined. To solve this you could do the following:
class Color{
public static function isValid(&$tokens, $i) {
include_once 'ColorRGBA.php';
include_once 'ColorHSLA.php';
return ColorRGBA::isValid($tokens, $i) || ColorHSLA::isValid($tokens, $i);
}
}
This works because the Color class is now fully defined and the ColorRGBA/ColorHSLA classes are defined only when isValid gets called.
You could also put include_once after the definition of the Color class.
To get around this type of problem, perhaps you should think about implementing a factory class. If that isn't your style, another elegant way around this issue is it use __autoload().
As for the maintenance of the code. It is going to be difficult depending on how many colors you introduce. Why not trying something like:
class Color{
public static function isValid($type, &$tokens, $i){
$class_name = 'Color'.$type;
if (!class_exists($class_name)) {
throw new Exception('Missing '.$class_name.' class.');
}
$class_name::isValid(&$tokens, $i);
}
}
PHP 3.5+
You cannot include ColorRGBA.php in Color.php and Color.php in ColorRGBA.php. You will get circular dependency. This is why you get class not found error.