Need Help in PHP OOP - php

I'm new in PHP OOP. I need some help for how to write the php OOP class then can call the class like below.
Query->table('user')->column('id','name')->where('name LIKE ?',
["name"=> 'John'])->orderby('name', 'desc');
But, I had try so many time, what I can get it something like below then stop.
Query->table('user')->column('id','name');
I'm running out of ideas and I had google a lot, but fail to find any solution.
Any suitable help is very much appreciated.

You just need to return on each function of class object itself using $this. All functions that you want to run "in chain" should be public. Check this code:
<?php
class ClassName
{
public function a()
{
// ...
return $this;
}
public function b($param)
{
// ...
return $this;
}
public function c()
{
// ...
return $this;
}
}
// testing
$obj = new ClassName;
$result = $obj->a()->b('someParam')->c();
You should read about method chaining.

Related

OOP PHP Class calling function1()->function2() from one line call

I am in a new quandary, and have been trying to work with it, I have gotten nothing but errors but I'm some what determined to learn how to do it, and after a bit of searching looks like it cannot be done the say that I want it to be.
In the class there are two or more functions(each can probably be called separably[sp]):
public function functionOne($some_var){
some other code to be run;
}
public function functionTwo($some_other_var){
some other code to be run after functionOne(), not called here;
}
From the caller (model):
$tClass = new TestClass();
$result = tClass->functionOne()->functionTwo();
echo $result;
Is this even possible from php? I know it works in frameworks like Laravel, which is where I learned about it. it would be nice... and so I am asking if I am doing it wrong? or ist it even possible, if it is where can i look for more as google had very very little information on the subject.
This is called fluent interface and will always work as soon as your method is doing
return $this;
Most likely it should be a good practice to make all your setters fluent. I would tend to say the only method that cannot be fluent would be your getters, otherwise, all other methods are perfect fit for a fluent interface.
class calculator {
private $result = 0;
public multiplication($number) {
$this->result *= $number;
return $this;
}
public addition() {
$this->result += $number;
return $this;
}
/* ... */
public getResult() {
return $this->result;
}
}
Usage:
$calculator = new calculator();
echo $calculator->addition(10)->multiplication(2)->getResult(); // 20

Method Chaining and Class Inheritance

I think I have more or less managed to get a grasp on OOP/Inheritance, and the basics of method chaining I think I understood as well. However I am still confused about how to actually use some of it.
I wanted to do something that I've seen when working with Magento before:
In Magento, I've seen some sort of "selector-function" used in method chaining. It's a little hard to put into words, but it was something along the lines of:
$categoryName = Mage::getModel('catalog/category')->load($categoryId)->getName();
It's the load($categoryId) part that interests me, as in, a function that selects some instance of something and allows me to run a function on that specific instance.
Now, I am writing a module that allows me to configure certain promotions on our website. Seeing as we'll have many different promotions and I want them to be easily configurable and modifiable, I wanted to do something similar.
So, if I wanted to be able to do something like this:
$prm = new Promotion();
$prm->addPromo('xmasPromo');
$prm->addPromo('nyPromo');
$prm->getPromo('xmasPromo')->setName('Promotion for Xmas!');
$prm->getPromo('nyPromo')->setName('Promotion for New Years!');
echo $prm->getPromo('xmasPromo')->getName(); // returns: Promotion for Xmas!
echo $prm->getPromo('nyPromo')->getName(); // returns: Promotion for New Years!
How would the class definition for that have to look like?
This may be much more simple or much more complicated than I anticipate. In either case, thanks a lot!
Edit:
So I did some testing around with the info deceze gave me, but I'm still confused.
Bad naming and putting 2 classes in 1 file aside, here's what I did:
class file:
class Promotion {
private $__arr = array();
public function addPromo($name) {
$this->__arr[$name] = new Promo();
}
public function getPromo($name) {
$this->__arr[$name];
}
}
class Promo {
private $name;
public function setName($name) {
$this->name = $name;
}
public function getName() {
return $name;
}
}
and the run file:
require_once 'class.php';
error_reporting(E_ALL);
$prm = new Promotion();
$prm->addPromo('xmasPromo');
$prm->addPromo('nyPromo');
$prm->getPromo('xmasPromo')->setName('Promotion for Xmas!');
$prm->getPromo('nyPromo')->setName('Promotion for New Years!');
echo 'X: '.$prm->getPromo('xmasPromo')->getName(); // returns: Promotion for Xmas!
echo "\n";
echo 'N: '.$prm->getPromo('nyPromo')->getName(); // returns: Promotion for New Years!
This gives me Fatal error: Call to a member function setName() on a non-object in /var/www/test/index.php on line 11.
But why? Shouldn't getPromo() give me back the object?
Thanks again..
Thanks to the great guys here, it works now. In case anyone were to pass by here with the same or a similar question, here's the final, working code:
Classes:
class Promotion {
private $__arr = array();
public function addPromo($name) {
$this->__arr[$name] = new Promo();
}
public function getPromo($name) {
return $this->__arr[$name];
}
}
class Promo {
private $name;
public function setName($name) {
$this->name = $name;
}
public function getName() {
return $this->name;
}
}
Test file:
require_once 'class.php';
error_reporting(E_ALL);
$prm = new Promotion();
$prm->addPromo('xmasPromo');
$prm->addPromo('nyPromo');
$prm->getPromo('xmasPromo')->setName('Promotion for Xmas!');
$prm->getPromo('nyPromo')->setName('Promotion for New Years!');
echo 'X: '.$prm->getPromo('xmasPromo')->getName(); // returns: Promotion for Xmas!
echo "\n";
echo 'N: '.$prm->getPromo('nyPromo')->getName(); // returns: Promotion for New Years!
Method chaining is really simple, all it does is use one particular element of PHP's syntax:
When a function returns an object, you can directly continue with -> after that function.
The longhand version can be:
$bar = $foo->bar();
$baz = $bar->baz();
echo $baz;
$foo->bar() returns an object ($bar) which has a method baz(), and that method returns some value ($baz). This can be written in shorthand like so:
echo $foo->bar()->baz();
$foo->bar() still returns an object which has a method baz(), so you can directly call it without assigning it to an intermediate variable. Maybe this makes it more obvious:
echo ( $foo->bar() )->baz();
You're calling the baz() method on whatever $foo->bar() returns.
$prm->getPromo('xmasPromo')->setName('Promotion for Xmas!');
As such, in your above case, all you need to do is to return an object which has the method setName from getPromo. I would assume getPromo is supposed to return some object of, say, the Promo class. If the Promo class has a method setName, you're all set.
If you want to chain methods you just need to always return the object like this
class Chain {
public function firstChain() {
//do something
return $this;
}
public function secondChain() {
//do some stuff
return $this;
}
}
Than when you have an instance of the class you do like this:
$obj = new Chain();
$obj->fistChain()->secondChain();

Mocking the function of a separate class

I have function test which return the repsonse of static function staticABC that belongs to separate class
function test()
{
return testA::staticABC();
}
Now I want to write PHPUnit cases for function test by mocking staticABC() function.Can any techie have idea about this ?
I don't think there is a way of mocking a function, but what you could do is use some kind of test double:
class SUT{
$staticCreator = array('testA::staticABC'); //Initialized to a default
//for production, would be better if injected somehow before using
function setStaticCreator($staticCreator){
$this->staticCreator=$staticCreator;
}
function test(){
return call_user_func($this->staticCreator);
}
}
and then run your test this way:
class Test extends ...{
function mockStaticABC(){
return "mock_string";
}
test_testfunction(){
$sut = new SUT();
$staticCreator = array($this,'mockStaticABC');
$sut->setStaticCreator($staticCreator);
$mock_return = $sut->test();
$this->assertEquals("mock_string",$mock_return);
}
}

Getting started with "Enhance PHP"

I am looking to incorporate a testing framework into a project I am building and came across Enhance PHP which I like but I am having some difficulty finding relevant information on-line since "enhance php" is such a commonly used phrase.
Has anyone worked with this framework that might be able to point me toward some helpful guide? Have you worked with a unit test framework that you think is amazingly better?
Thanks in advance.
In response to Gotzofter, this is the class to be tested:
<?php
include_once('EnhanceTestFramework.php');
class ExampleClass
{
private $OtherClass;
function __construct($mock = null)
{
if ($mock == null)
$this->OtherClass = new OtherExampleClass();
else
$this->OtherClass = $mock;
}
public function doSomething()
{
return $this->OtherClass->getSomething(1, 'Arg2');
}
}
class OtherExampleClass
{
public function getSomething()
{
return "Something";
}
}
class ExampleClassTests extends \Enhance\TestFixture
{
public function setUp()
{
}
public function tearDown()
{
}
public function verifyWithAMock()
{
$mock = \Enhance\MockFactory::createMock('OtherExampleClass');
$mock->addExpectation(
\Enhance\Expect::method('getSomething')
->with(1, 'Arg2')
->returns('Something')
->times(1)
);
$target = new ExampleClass($mock);
$result = $target->doSomething();
\Enhance\Assert::areIdentical("Something", $result);
$mock->verifyExpectations();
}
}
\Enhance\Core::runTests();
look at my constructor for ExampleClass.
Because enhance-php's site example injects the $mock object by calling new ExampleClass($mock), I am forced to change my ExampleClass constructor to handle a $mock as an input parameter.
Do I have to handle this for all classes that I want to subject to unit testing with the framework?
Thanks.
This:
function __construct()
{
$this->OtherClass = new OtherExampleClass;
}
Should be:
function __construct($otherClass)
{
$this->OtherClass = $otherClass;
}
Your mock is never injected at this point in your test:
$target = new ExampleClass($mock);
One thing I would recommend no matter what testing framework you are using is type-hinting against the expected class, or interface.
<?php
class ExampleClass
{
private $OtherClass; // OtherClass instance
public function __construct(OtherClass $OtherClass=null)
{
// ...
}
}
I'm no di expert, but I don't see the problem in letting each class call new if an instance isn't provided for a particular dependency. You could also of course take the approach where you use setter methods to configure dependencies.
<?php
class class ExampleClass
{
private $OtherClass; // OtherClass instance
public function setOtherClass(OtherClass $OtherClass)
{
$this->OtherClass = $OtherClass;
}
}
It is lame that the ExampleClass in the sample code doesn't even define the doSomething method from the ExampleDependencyClassTests, but if I understand correctly it looks like Enhance PHP is not forcing you to take a particular style of dependency injection. You can write the test class however you want, so for example if you took the setter method approach I mentioned above, you could change the example mock code to
<?php
class ExampleDependencyClassTests extends \Enhance\TestFixture
{
public function verifyWithAMock()
{
$mock = \Enhance\MockFactory::createMock('ExampleDependencyClass');
$mock->addExpectation(
\Enhance\Expect::method('getSomething')
->with(1, 'Arg2')
->returns('Something')
->times(1)
);
$target = new ExampleClass();
$target->setExampleDependencyClass($mock);
$result = $target->doSomething();
$mock->verifyExpectations();
}
}
Of course it would probly make sense to make the appropriate revisions to the ExampleClass!
<?php
class ExampleClass
{
private $ExampleDependencyClass;
public function addTwoNumbers($a, $b)
{
return $a + $b;
}
public function setExampleDependencyClass(
ExampleDependencyClass $ExampleDependecyClass
) {
$this->ExampleDependecyClass = $ExampleDependecyClass;
}
public function doSomething($someArg)
{
return 'Something';
}
}
I've worked with PHPUnit quite a bit, and honestly you'll have to face the same challenges with Mocks there. My 2 cents, try to model your tests without Mocks if possible ;)
There is a tutorial on NetTuts titled Testing Your PHP Codebase With Enhance PHP, which will definitely help you to get started.
And there is a Quick Start Guide on Enhance PHP.

How to chain method on a newly created object?

I would like to know whether there's a way to chain methods on a newly created object in PHP?
Something like:
class Foo {
public function xyz() { ... return $this; }
}
$my_foo = new Foo()->xyz();
Anyone know of a way to achieve this?
In PHP 5.4+, the parser's been modified so you can do something like this
(new Foo())->xyz();
Wrap the instantiation in parenthesis, and chain away.
Prior to PHP 5.4, when you're using the
new Classname();
syntax, you can't chain a method call off the instantiation. It's a limitation of PHP 5.3's syntax. Once an object is instantiated, you can chain away.
One method I've seen used to get around this is a static instantiation method of some kind.
class Foo
{
public function xyz()
{
echo "Called","\n";
return $this;
}
static public function instantiate()
{
return new self();
}
}
$a = Foo::instantiate()->xyz();
By wrapping the call to new in a static method, you can instantiate a class with method call, and you're then free to chain off that.
Define a global function like this:
function with($object){ return $object; }
You will then be able to call:
with(new Foo)->xyz();
In PHP 5.4 you can chain off a newly instantiated object:
http://docs.php.net/manual/en/migration54.new-features.php
For older versions of PHP, you can use Alan Storm's solution.
This answer is outdated - therefore want to correct it.
In PHP 5.4.x you can chain a method to a new-call. Let's take this class as example:
<?php class a {
public function __construct() { echo "Constructed\n"; }
public function foo() { echo "Foobar'd!\n"; }
}
Now, we can use this: $b = (new a())->foo();
And the output is:
Constructed
Foobar'd!
Further information may be found on the manual: http://www.php.net/manual/en/migration54.new-features.php
Well, this may be an old question but as with a lot of things in programming - eventually the answer changes.
Regarding PHP 5.3, no, you can't chain directly from the constructor. To expand on the accepted answer however, in order to properly accommodate for inheritance, you can do:
abstract class Foo
{
public static function create()
{
return new static;
}
}
class Bar extends Foo
{
public function chain1()
{
return $this;
}
public function chain2()
{
return $this;
}
}
$bar = Bar::create()->chain1()->chain2();
That will work just fine and will return you a new Bar() instance.
In PHP 5.4, however, you can simply do:
$bar = (new Bar)->chain1()->chain2();
Hopefully this helps someone stumbling across the question like I have!
It would be really helpful if they 'fix this' in a future release. I really appreciate the ability to chain (especially when populating collections):
I added a method to the base class of my framework called create() that can be chained off of. Should work with all descendant classes automatically.
class baseClass
{
...
public final static function create()
{
$class = new \ReflectionClass(get_called_class());
return $class->newInstance(func_get_args());
}
...
public function __call($method, $args)
{
$matches = array();
if (preg_match('/^(?:Add|Set)(?<prop>.+)/', $method, $matches) > 0)
{
// Magic chaining method
if (property_exists($this, $matches['prop']) && count($args) > 0)
{
$this->$matches['prop'] = $args[0];
return $this;
}
}
}
...
}
Class::create()->SetName('Kris')->SetAge(36);
Just for the sake of completeness (and for the fun of it...), since nobody seems to have mentioned the solution with the shortest (and least sophisticated) code.
For frequently used short-lived objects, especially when writing test cases, where you typically do lots of object creation, you may want to optimize for typing convenience (rather than purity), and sorta' combine Alan Storm's Foo::instantiate() factory method and Kenaniah's with() global function technique.
Simply make the factory method a global function with the same name as the class!. ;-o (Either add it as a convenience wrapper around the proper static Foo::instantiate() or just move it out there while nobody is looking.)
class Foo
{
public function xyz()
{
echo "Called","\n";
return $this;
}
}
function Foo()
{
return new Foo();
}
$a = Foo()->xyz();
NOTE:
I WOULDN'T DO THIS on production code. While kinda' sexy, this is an abuse on basic coding principles (like "principle of least surprise" (although this is actually rather intuitive syntax), or "don't repeat yourself", esp. if wrapping a real factory method with some parameters, which itself, BTW, is already an abuse of DRY...), plus PHP may change in he future to break code like this in funny ways.

Categories