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POFactory class with object initialization - trying to avoid static
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copied!<p>I'm trying to design a set of factory classes for our system, where some objects created by the factory also need to be initialized before they can be used properly.</p> <p>Example:</p> <pre><code>$foobar = new Foobar(); $foobar->init( $qux, ... ); // $foobar ready for usage </code></pre> <p>For the same of example, lets say that the <code>$qux</code> object is the only dependency that <code>Foobar</code> needs. What I'd like to get to is:</p> <pre><code>$foobar = Foo_Factory( 'bar' ); </code></pre> <p>In order to avoid the need to pass along the <code>$qux</code> object across the whole system and pass it to the factory class as another parameter, I'd like to perform initialization of <code>Foobar</code> directly in the factory class:</p> <pre><code>class Foo_Factory { public static function getFoo( $type ) { // some processing here $foo_name = 'Foo' . $type; $foo = new $foo_name(); $foo->init( $qux ); return $foo; } } </code></pre> <p>There are few solutions that come to mind, but none of them is ideal:</p> <ol> <li>Add a static setter method for <code>$qux</code> to the factory class, and let it store a reference to <code>$qux</code> in a private static variable. The system can set <code>$qux</code> at the start, and the factory class can prevent any future changes (for security reasons).<br />Although this approach works, using a static parameter for storing reference to <code>$qux</code> is problematic during unit testing (e.g. it happily lives survives between individual tests due to its static state).</li> <li>Create a new context class using Singleton pattern and let the factory class use it to get a reference to <code>$qux</code>. This might be a bit cleaner way to do this than option #1 (although we move the static problem from the factory class to the context class).</li> <li>Use dependency injection all the way, i.e. pass <code>$qux</code> to any object which uses the factory class, and let that object pass it along to the factory class as another parameter: <code>Foo_Factory::getFoo($type, $qux);</code>.</li> <li>Same as above (#3), but instead of passing <code>$qux</code> along the system, pass an instance of the factory class instead (i.e. in this case it would not be static, but instantiable).</li> </ol> <p>What would you recommend please? Any of the four alternatives mentioned above, or is there a better way to do this please?</p> <p>Note: I don't want to get into a <code>static is evil</code> flamewar here, just trying to come up with the best solution.</p>

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