Please explain execution flow of the below statement
$this->setPageID()
->paginate()
->sendCacheHeaders();
in below code
protected function main()
{
$this->setPageID()
->paginate()
->sendCacheHeaders();
}
public function setPageID()
{
$this->pageID = (int)$this->Router->getRealPageID();
return $this;
}
protected function paginate()
{
d('paginating with $this->pagerPath: ' . $this->pagerPath);
$Paginator = Paginator::factory($this->Registry);
$Paginator->paginate($this->Cursor, $this->PER_PAGE,
array('currentPage' => $this->pageID,
'path' => '{_WEB_ROOT_}/' . $this->pagerPath));
$this->pagerLinks = $Paginator->getLinks();
return $this;
}
protected function sendCacheHeaders()
{
return $this;
}
What is the flow of this methods execution?, Is there any data transfer/communication b/w these methods?
I call this chaining. Basically, your functions are part of a class and that class has an instance ($class = new class()).
Your functions are returning that instance. While not a best practice per se, it does mean that you can chain the calls back to back.
$this->setPageID() ->paginate() ->sendCacheHeaders();
Note how each function returns $this. So it's the same as writing
$this->setPageID();
$this->paginate();
$this->sendCacheHeaders();
They're not communicating with each other explicitly. They all belong to the same class instance so they can access any variables belonging to that class (or any parent classes). So when paginate() sets $this->pagerLinks, any function in that class can access that value.
$this
->setPageID() // sets class variable $pageID from Router class. Returns current class.
->paginate() // Setup of Paginator class, assigns links to $pagerLinks. Returns current class
->sendCacheHeaders(); // does nothing. Returns current class
Because every function return $this so it's possible to chain method calls. Without returning $this your call will look like this:
$this->setPageID();
$this->paginate();
$this->sendCacheHeaders();
Related
I have seen in Laravel calling multiple method in the single line, example:
DB::get('test')->toJson();
I have a cool class and view method in that class.
$this->call->view('welcome')->anotherMethod();
I would like to call another method also? Where should I make that method?
DB::get() seems to be a method returning an object, where you can call other functions (I think a result object of a database query). If you want to call multiple functions on one object in one line, you have to return $this in your functions, e.g.:
class View {
public static function factory {
// The question is: How useful is this factory function. In fact: useless in
// the current state, but it can be extended in any way
return new self;
}
public function one() {
// do something
return $this;
}
public function two() {
// do something
return $this;
}
}
Then you can do:
$class = new View();
$class->one()->two();
// it's also possible to use the `factory` function
// you should think about, how useful this approach is in your application
$class = View::factory()->one()->two();
That's how you can do it in php, if laravel has some helpers for that, i can't say :)
Basically I have a method which I need to run when the constructor is finished (the method is called persist() and it simply saves a key which was generated during the constructor into the session). It seems simple enough, and it works - at the end of __construct I make the call to $this->persist().
The problem is that this class is subclassed many times. This causes two issues.
One, that I must remember to make the call to persist() at the end of every single subclass's __construct method. Not a huge issue but it doesn't feel very OOP, I feel like I could be dealing with this in the parent class some how and that this would be better.
Two, if a subclass is subclassed (which it is), and the __construct methods chained (i.e. parent::__construct called), the persist() method will be getting fired multiple times, once for each time the class has been subclassed. It only needs to be called once, when all construction is complete. In this scenario it doesn't really break anything because when the persist method is called for the 2nd, 3rd time etc., it simply overwrites what was persisted before. But that isn't the point, because I just feel like there must be a better way and that there are scenarios out there that would not allow for the method to be called multiple times.
Is a factory method which constructs the object and then makes the call to persist on it the only way? I can go down this route but I am just wondering if there is a way to do it without, so that the method from the parent is always called after construction.
Here is some example code:
session_start();
is(!isset($_SESSION["Component"])) $_SESSION["Component"] = [];
abstract Class Component
{
private $id;
protected $key;
function __construct($id = NULL)
{
$this->id = $id;
$this->key = [];
$this->key["something"] = "SomeValue";
$this->persist(); // First call
}
protected function persist()
{
if($this->id !== NULL) $_SESSION["Component"][$this->id] = $this->key;
}
}
Class SomeComponent extends Component
{
function __construct($id = NULL)
{
parent::__construct($id);
$this->key["something-else"] = "SomeOtherValue";
$this->persist(); // Second call
}
}
Class SomeSpecialistComponent extends SomeComponent
{
function __construct($id = NULL, $key = [])
{
parent::__construct($id);
$this->key = array_merge($this->key, $key);
$this->persist(); // Third call
}
}
$my_component = new SomeSpecialistComponent(1, ["example" => true]);
Only trick I found to get something similar (except I wanted to execute things before and not after) is using a parent class with an abstract method as a new constructor :
abstract class RequireThings {
public function __construct() {
$this->constructAndPersist();
$this->persist();
}
abstract function constructAndPersist();
// You could also set this function in your children classes by the way.
public function persist() {
echo ' Then I persist!';
}
}
class UsingPersist extends RequireThings {
public function constructAndPersist() {
echo 'I do my things first.';
}
}
$class = new UsingPersist();
Would output :
I do my things first. Then I persist!
If I got your problem right, it should be enough to avoid problems you are facing.
The main downside of this solution is that you have to use a new function which is supposed to be your new constructor for this type of classes. That's why I set the __constructPersist as abstract, it forces the behavior as wanted.
I would argue in favor of the factory method, mostly because you're doing real work in the constructor. Remove the call where work is being done in the constructors ($this->persist) and place it in the factory:
class ComponentFactory
{
const SOME_COMPONENT = 'component';
const SOME_SPECIALIST_COMPONENT = 'specialist_component';
public static function make($type, $id, $key = null)
{
switch($type) {
case self::SOME_COMPONENT:
$component = new SomeComponent($id);
break;
case self::SOME_SPECIALIST_COMPONENT:
$component = new SomeSpecialistComponent($id, $key);
break;
}
$component->persist();
return $component;
}
}
$component = ComponentFactory::make(ComponentFactory::SOME_COMPONENT, 42);
$specialist = ComponentFactory::make(
ComponentFactory::SOME_SPECIALIST_COMPONENT,
43,
[
'something' => 'SomeValue',
'something-else' => 'SomeOtherValue',
]
);
According to Miško Hevery (author of AngularJS and agile coach at Google) these are the warning signs of doing too much work in the constructor:
new keyword in a constructor or at field declaration
Static method calls in a constructor or at field declaration
Anything more than field assignment in constructors
Object not fully initialized after the constructor finishes (watch
out for initialize methods)
Control flow (conditional or looping logic) in a constructor
CL does complex object graph construction inside a constructor
rather than using a factory or builder
Adding or using an initialization block
just create another function that you'll call before $this->persist and override that in your subclasses instead of the constructor
Here's my test:
<?php
require __DIR__ . '/vendor/autoload.php';
class HasStatic {
public static function static_method() {
return true;
}
}
class SUT {
public $has_static;
public function __construct() {
$this->has_static = new HasStatic();
}
public function call_static() {
// A parse error :<
// $this->has_static::static_method();
$has_static = $this->has_static;
return $has_static::static_method();
}
}
class PhpStaticCallOnProperty extends PHPUnit_Framework_TestCase {
public function testPhpStaticCallOnProperty() {
$sut = new SUT();
$this->assertTrue($sut->call_static(), 'call_static() succeeded');
}
}
As you can see, I discovered that $this->has_static::static_method(); yields a parse error.
Is there a clean way to make this call without the extra assignment?
Static methods are black boxes of functionality where you explicitly define everything going in (parameters) and out (return value). As such, they are not tied to an object - and you shouldn't call them using an object reference. static_method() should only ever be called using HasStatic::static_method(), or self::static_method() from within the HasStatic class.
There's nothing inherently wrong with static methods - I strongly disagree with tereško saying they should be avoided. If a method doesn't need an object's context, it may as well be static.
The parse error occurs because there's no reason to use the scope resolution operator (::) on a property. Variable class names do mean the following will work:
$foo = 'HasStatic';
$foo::static_method(); // equivalent to HasStatic::static_method()
However that variable cannot be a property - you'll have to assign it to a temporary variable if you want to call the method in this way.
I've got a problem with mocking an overloaded __get($index) method.
The code for the class to be mocked and the system under test that consumes it is as follows:
<?php
class ToBeMocked
{
protected $vars = array();
public function __get($index)
{
if (isset($this->vars[$index])) {
return $this->vars[$index];
} else {
return NULL;
}
}
}
class SUTclass
{
protected $mocky;
public function __construct(ToBeMocked $mocky)
{
$this->mocky = $mocky;
}
public function getSnack()
{
return $this->mocky->snack;
}
}
Test looks as follows:
<?php
class GetSnackTest extends PHPUnit_Framework_TestCase
{
protected $stub;
protected $sut;
public function setUp()
{
$mock = $this->getMockBuilder('ToBeMocked')
->setMethods(array('__get')
->getMock();
$sut = new SUTclass($mock);
}
/**
* #test
*/
public function shouldReturnSnickers()
{
$this->mock->expects($this->once())
->method('__get')
->will($this->returnValue('snickers');
$this->assertEquals('snickers', $this->sut->getSnack());
}
}
Real code is a little bit more complex, though not much, having "getSnacks()" in its parent class. But this example should suffice.
Problem is I get the following error, when executing the test with PHPUnit:
Fatal error: Method Mock_ToBeMocked_12345672f::__get() must take exactly 1 argument in /usr/share/php/PHPUnit/Framework/MockObject/Generator.php(231)
When I debug I can't even reach the test method. It seems it breaks at setting up the mock object.
Any ideas?
__get() takes an argument, so you need to provide the mock with one:
/**
* #test
*/
public function shouldReturnSnickers()
{
$this->mock->expects($this->once())
->method('__get')
->with($this->equalTo('snack'))
->will($this->returnValue('snickers'));
$this->assertEquals('snickers', $this->sut->getSnack());
}
The with() method sets the argument for the mocked method in PHPUnit. You can find more details in the section on Test Doubles.
It's a bit hidden in the comments, but #dfmuir's answer put me on the right track. Mocking a __get method is straight forward if you use a callback.
$mock
->method('__get')
->willReturnCallback(function ($propertyName) {
switch($propertyName) {
case 'id':
return 123123123123;
case 'name':
return 'Bob';
case 'email':
return 'bob#bob.com';
}
}
);
$this->assertEquals('bob#bob.com', $mock->email);
Look in the mocked magic method __get. Probably you call there one more __get method from another and not properly mocked object.
What you are doing in the setUp method of your GetSnackTest class is incorrect.
If you want the code of the __get method to be executed (which would be the point of your test> I suppose), you have to change the way you call setMethods in the setup method.
Here's the complete explanation, but here's the relevant part:
Passing an array containing method names
The methods you have identified:
Are all stubs,
All return null by default,
Are easily overridable
So, you need to call setMethods by passing null, or by passing an array that contains some methods (the ones that you really want to stub), but not- __get (because you actually want the code of that method to be executed).
The, in the shouldReturnSnickers method, you will simply want to want to call $this->assertEquals('snickers', $this->sut->getSnack());, without the preceding lines with the expect part.
This will ensure the code of your __get method is actually executed and tested.
withAnyParameters() method can help you, this works correct:
$this->mock -> expects($this -> once())
-> method('__get') -> withAnyParameters()
-> will($this -> returnValue('snikers'));
I've run into a problem and I'm not sure if this is just normal behaviour or if I wrote something wrong. I have a method in my base class that applies a global filter to a given class by way of creating a proxy for all new instances of that particular class. The way I planned to go about it is as follows:
Attach static $global_filter (the proxy) to the class I want to be filtered, which extends the base class object
Via my loading mechanism, return the proxy instead of the actual class upon new instantiations (which will mask method calls and apply filters accordingly)
However, I am getting stuck in step 1 and it seems that when I try to assign static $global_filter to the descendent class I want filtered, my base class object also gets the same assignment, which breaks everything else that extends from it.
Please see below for relevant code:
class object {
public static $global_filter;
public function _filterGlobal($class, $method, $callback) {
if ( !is_object($class::$global_filter) ) {
$class::$global_filter = new filterable(null);
# Replace the object being called with the new proxy.
}
var_dump($class);
var_dump($class::$global_filter); // `filterable`
var_dump(\core\blueprint\object::$global_filter); // Returns same as line above
die();
return $class::$global_filter->_add($method, $callback);
}
}
Both $class::$global_filter and \core\blueprint\object::$global_filter (the base class) are returning same instance. Whereas I expected object::$global_filter to be null.
I'm not using late static binding in order to preserve consistency (both single-object filters and global filters are called much in the same way non-statically).
This question seems relevant
Any help will be much appreciated :)
Edit, full example
This would be a concrete class, which extends model which extends object
<?php
use core\blueprint\model;
class modelMock extends model {
protected $schema = array();
public function method($test) {
return $test;
}
}
This would be another object (e.g a controller), which extends object aswell. It applies a filter to all new instances of model
<?php
use core\blueprint\object;
class objectMock extends object {
public function applyFilters() {
$this->_filterGlobal('core\blueprint\model', 'method', function($self, $chain) {
$chain->params[0] = 'new param'; // adjust the paramters
return $chain->next();
});
}
}
when I try to assign static $global_filter to the descendent class I want filtered, my base class object also gets the same assignment
Yes, indeed this happens. A static property in essence is a global variable, constrained within the class's namespace. Running into problems with global variables is often an indication you're not using the best solution.
To solve your problem, you could make the filter a (non-static) property:
$class->$filter = new Whatever();
But as always, there's more roads that lead to Rome, and I would advise you to look for alterative ways to do it.
I don't know if this is a help for you:
class a {
public static $type;
public static function setType($class, $newType) {
$class::$type = $newType;
var_dump($class::$type);
}
}
class b {
public static $type = 'myType';
}
var_dump(b::$type);
a::setType('b', 'yourType');
var_dump(a::$type);
May be you have not defined the static property to the concrete class.
Thanks everyone for you help, I spent some time on it this morning and managed to solve my problem. It's a bit of a workaround but here's how it goes:
public function _filterGlobal($class, $method, $callback) {
if ( !is_object($class::$global_filter[$class]) ) {
$class::$global_filter[$class] = new filterable(null);
# Replace the object being called with the new proxy.
}
return $class::$global_filter[$class]->_add($method, $callback);
}
So basically in order to get unique static variables working in child classes without having to explicitly define them, you can use an array that stores the child's class name as a key and then access these variables via a getter.