Aggregating objects within PHP5

by , Jun. 26, 2010 at 12:19 PM

Scripts: PHP, MySQL

If you did not know, it is worth to know  that from PHP5 the full (OOP) Object Oriented programming paradigm is totally integrated.

In this article, i am going talk about one of the technics of OOP with PHP. If you do not have any notion in Object oriented programming, in any programming languages like Java, C++, C#, Ruby, ...
i will advise to first learn OOP paradigm or find some introduction to Object oriented programming  on the internet. You may purchase some book on this matter, if you want.
When you go OOP programming, you will in one or other way interact with some objects. Thus aggregation of object refers to a situation where one or more objects( the Aggregated objects ) are passed to another object( the Aggregating object ) to perform some operations or methods within that object that called it.

The aggregating object instatiates or creates an object of the aggregated class in its constructor method. To be able for the aggregating object calling methods or public properties of the aggragated objects, the PHP5 magic method (__call) come in handful. Within this __call method, another PHP function (call_user_func_array) comes in handy for matching the aggregated object to its called method.

May be it is not easy to figure out how it is all about. But in the classes defined here underneath, you can get it. You can also check the demonstration of this code

 

  1. <?php
  2. /**
  3.  * Description of Product
  4.  *
  5.  * @author Emmanuel
  6.  */
  7. class Product
  8. {
  9. private $name = null;
  10. private $price = null;
  11.  
  12. public function setProdName($name=null){
  13. $this->name = ucfirst($name);
  14. }
  15. public function getProdName(){
  16. if(isset($this->name)) return $this->name;
  17. else return null;
  18. }
  19. public function setProdPrice($price = null){
  20. if(isset($price))$this->price = $price;
  21. }
  22. public function getProdPrice(){
  23. if(isset($this->price)) return $this->price;
  24. }
  25. }
  26.  
  27. /**
  28.  * Description of Buyer of the product
  29.  *
  30.  */
  31. class Buyer{
  32. private $name = null;
  33.  
  34. public function setBuyername($name){
  35. if(isset($name)) $this->name = $name;
  36. }
  37. public function getBuyerName(){
  38. if(isset($this->name)) return $this->name;
  39. }
  40. }
  41.  
  42. /**
  43.  * Description of ProductCategory
  44.  *
  45.  */
  46. class Manufacturer
  47. {
  48. private $name = null;
  49. protected $product;
  50. protected $buyer;
  51.  
  52. public function __construct(){
  53. $this->product = new Product;
  54. $this->buyer = new Buyer;
  55. }
  56.  
  57. //
  58. public function setName($name){
  59. if(isset($name)){
  60. $this->name = $name;
  61. }
  62. }
  63.  
  64. //
  65. public function getName(){
  66. return $this->name ;
  67. }
  68.  
  69. public function __call($method, $arguments){
  70. if(method_exists($this->product, $method)){
  71. array($this->product, $method),
  72. $arguments
  73. );
  74. }
  75. //
  76. if(method_exists($this->buyer, $method)){
  77. array($this->buyer, $method),
  78. $arguments
  79. );
  80. }
  81. }
  82. }
  83.  
  84. $factory = new Manufacturer();
  85. $factory->setName("FACTORY_1");
  86. //Call methods from aggregated Product object
  87. $factory->setProdName("PRODUCT_1");
  88. $factory->setProdPrice("&euro;150,-");
  89. //Call methods from aggregated Buyer object
  90. $factory->setBuyerName("Emmanuel Manu");
  91.  
  92. echo "Manufacturer's name : ".$factory->getName()."<br/>";
  93. echo "Product's name : ".$factory->getProdName()."<br/>";
  94. echo "Product's price : ".$factory->getProdPrice()."<br/>";
  95. echo "Buyer : ".$factory->getBuyerName()."<br/>";
  96. ?>

 

If you would want to see the code of the classes above in action, go to this link for demonstration. The echo's in the code will print up the name of the factory, product's name and its price, the  name of the buyer

DEMONSTRATION>>

If we talk about performance issues, the advantages of aggregating objects within other objects mainly come from its lower overload, since most of the time only one object is shared by other objects. However, this advantage might be discarded in the case of having a class for database connection shared by other multiple classes. You may run into difficulties if multiple database connections are established to the same server, causing a noticeable detriment to the system, particularly if your site is attracting many visitors.

Of course it is not a good idea to design your DB object with Objects Aggregation, instead the Singleton Pattern may be in this case, providing one and only existing object for DB, very useful. This is to avoid creating new instances of a DB class with key (new) and end up with overheading the system beacause every instantiated object is kept in the memory of the system.

Patterns in PHP is also very important to effectively and efficiently design not only webapplications but also any soft. applications. Patterns topics will come in the latter articles.

Available Comments :

Your Attention! Please do not post message with spam on this blog. We try to be cool to each other and post relevant comments and relating to the appropriated topic or entry. Let's try to get a nice conversation over here.

Leave a comment

Required!
Required!

Required!
Required!

Latest News

  • Aug. 30, 2014 at 10:09
    Netherlands international Daley Blind is set to become Manchester United's fifth summer signing after a fee is agreed with Ajax.
    Read more»
  • Aug. 30, 2014 at 09:43
    Military units in Lesotho have seized the police headquarters in a possible coup attempt, officials in the southern African mountain kingdom...
    Read more»
  • Aug. 30, 2014 at 09:34
    The Liberal Democrats are to pledge giving fathers an extra four weeks' paternity leave in their manifesto for the general election.
    Read more»
  • Aug. 30, 2014 at 09:24
    A five-year-old boy with a brain tumour, missing since being taken out of hospital by his parents against medical advice, may be in Spain, H...
    Read more»
  • Aug. 30, 2014 at 09:15
    The Foreign Office confirms the body of John Alder, one of 10 Britons killed in the Malaysia Airlines crash, has been identified.
    Read more»
  • Aug. 30, 2014 at 08:55
    David Cameron and Nick Clegg are to meet for talks to try to reach agreement on new measures to tackle the threat posed by Islamist extremis...
    Read more»
  • Aug. 30, 2014 at 08:42
    Watch the latest news summary from BBC World News. International news updated 24 hours a day.
    Read more»
  • Aug. 30, 2014 at 08:00
    Most of 24 gold miners trapped underground in northern Nicaragua since Thursday have been rescued, officials say.
    Read more»
  • Aug. 30, 2014 at 06:11
    EU leaders are to meet in Brussels to consider how to respond to Russia following accusations that its troops are fighting inside Ukraine.
    Read more»
  • Aug. 30, 2014 at 05:01
    Housing experts are calling for minimum standards in the private rental market to prevent landlords from exploiting vulnerable tenants.
    Read more»
  • Aug. 30, 2014 at 04:40
    Leaders of the EU's 28 states are heading to Brussels for a special Saturday summit to decide who will fill two of Europe's top jobs.
    Read more»
  • Aug. 30, 2014 at 03:38
    Some 230 members of an Orthodox Jewish group begin leaving a village in western Guatemala after a bitter row with the local indigenous commu...
    Read more»
  • Aug. 30, 2014 at 03:29
    Controversial British MP George Galloway is taken to hospital with a suspected broken jaw after he was attacked on a London street.
    Read more»
  • Aug. 30, 2014 at 03:18
    The bizarre tale of the pig singing competition
    Read more»
  • Aug. 30, 2014 at 03:00
    The multi-million dollar makeover that's divided a nation
    Read more»
  • Aug. 30, 2014 at 02:55
    Italian PM Matteo Renzi announces measures to quicken the pace of the country's notoriously slow justice system to help the struggling econo...
    Read more»
  • Aug. 30, 2014 at 02:32
    A US judge strikes down part of a Texas abortion law that would have closed more than a dozen clinics.
    Read more»
  • Aug. 30, 2014 at 01:44
    Ecuador says it will introduce the world's first digital currency issued by a central bank and it will go into circulation in December.
    Read more»
  • Aug. 30, 2014 at 01:37
    The natural resources used to make 'green' homes
    Read more»
  • Aug. 30, 2014 at 00:38
    ...but not discouraged - gay son in video row speaks out
    Read more»

Recent Comments:

Ehcjntublr

Jun. 11, 2014 at 06:06 PM

leebvfnnbovfmoebzjsbhjkf, http://www.pykbyrhrlo.com/ spdwthctlr

Natural hair care products

May. 27, 2014 at 09:05 AM

These are really great ideas in on the topic of blogging. You have touched some pleasant things here. Any way keep up wrinting.

Remedies for piles

May. 18, 2014 at 05:44 PM

Thanks for finally writing about > %blog_title% < Loved it!

Website

Mar. 25, 2014 at 08:19 PM

There are books, home study courses, workshops and other means of information, to gain the knowledge required to become the alpha leader. If you want ... Read more»

Titia

Feb. 15, 2014 at 01:48 AM

buy car insurance online prozac 40mg no rx best deals on vigra and cialis website auto insurance quoye www.evansvillecommunitytheatre.com ... Read more»

Archives:

Meet me on facebook: