Resolve YAML::parse deprecation notice.

See igorw/ConfigServiceProvider#46

When the above PR is merged, we can revert this commit. The current code
is throwing errors in the test suite due to deprecation notices from Yaml::parse.
We haven't upgraded this package so no idea why we started getting notices like
this but it is what it is.

Parse method now triggers a warning if you give it a path. It expects the yaml file
contents, not a path. This patch adds a provider that extends Igor's and makes
this change. We then sub this provider into the ChainConfigProvider instead of
using SilexConfigServiceProvider's default.

Author: Dustin Wheeler

classes/OpenCFP/Application.php

@@ -2,13 +2,18 @@
 
 namespace OpenCFP;
 
+use Igorw\Silex\ChainConfigDriver;
+use Igorw\Silex\JsonConfigDriver;
+use Igorw\Silex\PhpConfigDriver;
+use Igorw\Silex\TomlConfigDriver;
 use League\OAuth2\Server\Exception\OAuthException;
 use OpenCFP\Provider\ApplicationServiceProvider;
 use OpenCFP\Provider\Gateways\ApiGatewayProvider;
 use OpenCFP\Provider\Gateways\OAuthGatewayProvider;
 use OpenCFP\Provider\Gateways\WebGatewayProvider;
 use OpenCFP\Provider\ImageProcessorProvider;
 use OpenCFP\Provider\TwigServiceProvider;
+use OpenCFP\Provider\YamlConfigDriver;
 use Silex\Application as SilexApplication;
 use Igorw\Silex\ConfigServiceProvider;
 use OpenCFP\Provider\DatabaseServiceProvider;
@@ -120,7 +125,20 @@ private function camelCaseFrom($slug)
      */
     protected function bindConfiguration()
     {
-        $this->register(new ConfigServiceProvider($this->configPath(), [], null, 'config'));
+        /**
+         * Replace reference to `ChainConfigDriver` with `null` when PR below is merged.
+         * Symfony's YAML package deprecated allowing a path to be passed to `parse` method.
+         * This was causing our test-suite to fail. When this is merged, we can upgrade and
+         * all will be well again.
+         *
+         * @see https://github.com/igorw/ConfigServiceProvider/pull/46
+         */
+        $this->register(new ConfigServiceProvider($this->configPath(), [], new ChainConfigDriver([
+            new PhpConfigDriver(),
+            new YamlConfigDriver(), // This is ours; in OpenCFP/Provider/YamlConfigDriver.
+            new JsonConfigDriver(),
+            new TomlConfigDriver(),
+        ]), 'config'));
 
         if ( ! $this->isProduction()) {
             $this['debug'] = true;

classes/OpenCFP/Provider/YamlConfigDriver.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace OpenCFP\Provider;
+
+use Igorw\Silex\YamlConfigDriver as IgorYamlConfigDriver;
+use Symfony\Component\Yaml\Yaml;
+
+class YamlConfigDriver extends IgorYamlConfigDriver
+{
+    public function load($filename)
+    {
+        if (!class_exists('Symfony\\Component\\Yaml\\Yaml')) {
+            throw new \RuntimeException('Unable to read yaml as the Symfony Yaml Component is not installed.');
+        }
+        $config = Yaml::parse(file_get_contents($filename));
+        return $config ?: array();
+    }
+}