Add code to allow configuration for the plugin factory to be stored on a per install basis.

PHPCI/Plugin/Util/Factory.php

@@ -37,6 +37,28 @@ class Factory {
         );
     }
 
+    /**
+     * Trys to get a function from the file path specified. If the
+     * file returns a function then $this will be passed to it.
+     * This enables the config file to call any public methods.
+     *
+     * @param $configPath
+     * @return bool - true if the function exists else false.
+     */
+    public function addConfigFromFile($configPath)
+    {
+        // The file is expected to return a function which can
+        // act on the pluginFactory to register any resources needed.
+        if (file_exists($configPath)) {
+            $configFunction = require($configPath);
+            if (is_callable($configFunction)) {
+                $configFunction($this);
+                return true;
+            }
+        }
+        return false;
+    }
+
     public function getLastOptions() {
         return $this->currentPluginOptions;
     }

Tests/PHPCI/Plugin/Util/ExamplePluginConfig.php

@@ -0,0 +1,22 @@
+<?php
+return function (PHPCI\Plugin\Util\Factory $factory) {
+    $factory->registerResource(
+        // This function will be called when the resource is needed.
+        function() {
+            return array(
+                'Foo' => "Stuff",
+                'Bar' => "More Stuff"
+            );
+        },
+
+        // In addition to the function for building the resource the system
+        // also needs to be told when to load the resource. Either or both
+        // of the following arguments can be used (null to ignore)
+
+        // This resource will only be given when the argument name is:
+        "ResourceArray",
+
+        // The resource will only be given when the type hint is:
+        PHPCI\Plugin\Util\Factory::TYPE_ARRAY
+    );
+};

Tests/PHPCI/Plugin/Util/FactoryTest.php

@@ -148,6 +148,33 @@ class FactoryTest extends \PHPUnit_Framework_TestCase {
         $this->assertArrayHasKey('thing', $plugin->Options);
     }
 
+    public function testAddConfigFromFile_ReturnsTrueForValidFile()
+    {
+        $result = $this->testedFactory->addConfigFromFile(
+            realpath(__DIR__ . "/ExamplePluginConfig.php")
+        );
+
+        $this->assertTrue($result);
+    }
+
+    public function testAddConfigFromFile_RegistersResources()
+    {
+        $this->testedFactory->addConfigFromFile(
+            realpath(__DIR__ . "/ExamplePluginConfig.php")
+        );
+
+        $namespace = '\\PHPCI\\Plugin\\Tests\\Util\\';
+        $pluginName = $namespace  . 'ExamplePluginWithSingleRequiredArg';
+
+        $plugin = $this->testedFactory->buildPlugin($pluginName);
+
+        // The Example config file defines an array as the resource.
+        $this->assertEquals(
+            array("bar" => "Hello"),
+            $plugin->RequiredArgument
+        );
+    }
+
     /**
      * Registers mocked Builder and Build classes so that realistic plugins
      * can be tested.