CODEWITHSUNDEEP
phpoopdesign-patterns
user312650
user312650

Reputation:

How to have a class spread across many source files?

I am currently working on a PHP project which includes extensive database usage. The basics are: I have a PDOFactory class which follows the Factory pattern and an abstract SQL class with static methods (just a container for those methods) which in turn talks to PDOFactory

As I said, the project involves extensive database usage, so the SQL class will contain numerous methods. However, they could be easily grouped, depending on what they deal with (i.e. session storage, user logging on/off, etc.). That would make the SQL class much easier to maintain and so on and forth. And here comes the big question: Can I have the source of the class contents spread across many files? There could be (at least) two possible solutions to this problem:

I know there is no multiple inheritance in PHP, so that rules out option No. 1. Is option No. 2 even possible? Or does anybody know of better solutions to this problem?

*Or actually pre-pre-processor directives, since PHP is a pre-processor. :)

EDIT:

Here's an attempt to answer this question, based on Kalium's suggestion. It's a mess to read, but it works. However, I'm gonna stick with Bill's method as it's way cleaner. 

class SQL {

  private static $oInstance = false;
  public static function getInstance()
  {
    if( self::$oInstance == false )
    {
      self::$oInstance = new self();
    }
    return self::$oInstance;
  }

  public $SESSION;

  private function __construct()
  {
    $this->SESSION = new SESSION;
  }
}

// this would be in another file
class SESSION {
  public function printOne()
  {
    echo "One";
  }
}


SQL::getInstance()->SESSION->printOne(); // outputs "One"

?>

Upvotes: 0

Views: 708

Answers (4)

nathan
nathan

Reputation: 5452

to me, it sounds like you're trying to create a monolithic chunk of code, which is the exact opposite of class based OO code - I'd recommend following the DAO blueprint of the Java core patterns, and implementing it in PHP for what you want to do :) that should cover all you're questions

Upvotes: 0

Bill Karwin
Bill Karwin

Reputation: 562438

I think you should use the Builder pattern for your SQL instead of a motley container of static methods.

No, there is no multiple inheritance in PHP. Use delegation instead.

No, you can't include files to define methods of a class. You can only include files in contexts where code is executing, not in the middle of a class definition:

<?php

include("define-functions.php"); // OK

class Foo
{
  include("define-methods.php");  // ERROR

  function foo()
  {
    include("method-body.php"); // OK
  }
}

PHP Parse error:  syntax error, unexpected T_INCLUDE, expecting T_FUNCTION 
in foo.php on line 7

Re your comment:

Since you're committed to using only static methods, why bother with a class at all? Just define functions in the global scope. Then you can include() as many as you want:

<?php

include("SQLSession.php");
include("SQLUser.php");
include("SQLblahblah.php");

SQLSession.php:

<?php

function SQLSessionStart()
{
   ...
}

function SQLSessionEnd()
{
   ...
}

You don't have access to static class member data with this solution, but you can just use global variables.

Upvotes: 1

Sjoerd
Sjoerd

Reputation: 75619

Upvotes: 1

Kalium
Kalium

Reputation: 4682

I think you may be approaching this wrong. That's certainly not the best way to go about it. Try breaking the many functions into smaller utility classes and then using those to composite a larger class.

Upvotes: 2

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