support automatic client and facotry discovery

Author: xabbuh

.travis.yml

@@ -20,6 +20,8 @@ matrix:
   include:
     - php: 5.4
       env: deps="low"
+    - php: 5.6
+      env: PACKAGES="php-http/discovery:^1.0 php-http/guzzle6-adapter:^1.0 php-http/message:^1.0"
     - php: 7.0
       env: xdebug="yes"
 
@@ -28,6 +30,7 @@ before_install:
   - composer self-update
 
 install:
+  - if [ "$PACKAGES" != "" ]; then composer require --no-update $PACKAGES; fi
   - if [ "$deps" = "low" ]; then composer update --prefer-lowest --prefer-stable --ignore-platform-reqs; fi
   - if [ "$deps" = "" ]; then composer install; fi
 

CHANGELOG.md

@@ -40,6 +40,9 @@ CHANGELOG
       ->build();
   ```
 
+  You can avoid calling `setHttpClient()` and `setRequestFactory` by installing
+  the [HTTP discovery](http://php-http.org/en/latest/discovery.html) package.
+
 * Bumped the required versions of all `php-xapi` packages to the `1.x` release
   series.
 

UPGRADE.md

@@ -40,6 +40,9 @@ Upgrading from 0.4 to 0.5
       ->build();
   ```
 
+  You can avoid calling `setHttpClient()` and `setRequestFactory` by installing
+  the [HTTP discovery](http://php-http.org/en/latest/discovery.html) package.
+
 Upgrading from 0.2 to 0.3
 -------------------------
 

composer.json

@@ -30,6 +30,9 @@
         "php-http/mock-client": "^0.3",
         "php-xapi/test-fixtures": "^1.0"
     },
+    "suggest": {
+        "php-http/discovery": "For automatic discovery of HTTP clients and request factories"
+    },
     "conflict": {
         "xabbuh/xapi-client": "*"
     },

spec/XApiClientBuilderSpec.php

@@ -3,7 +3,10 @@
 namespace spec\Xabbuh\XApi\Client;
 
 use Http\Client\HttpClient;
+use Http\Discovery\HttpClientDiscovery;
+use Http\Discovery\MessageFactoryDiscovery;
 use Http\Message\RequestFactory;
+use PhpSpec\Exception\Example\SkippingException;
 use PhpSpec\ObjectBehavior;
 
 class XApiClientBuilderSpec extends ObjectBehavior
@@ -33,6 +36,10 @@ function its_methods_can_be_chained(HttpClient $httpClient, RequestFactory $requ
 
     function it_throws_an_exception_if_the_http_client_is_not_configured(RequestFactory $requestFactory)
     {
+        if ($this->isAbleToDiscoverHttpClient()) {
+            throw new SkippingException('The builder does not throw an exception if it can automatically discover an HTTP client.');
+        }
+
         $this->setRequestFactory($requestFactory);
         $this->setBaseUrl('http://example.com/xapi/');
 
@@ -41,17 +48,62 @@ function it_throws_an_exception_if_the_http_client_is_not_configured(RequestFact
 
     function it_throws_an_exception_if_the_request_factory_is_not_configured(HttpClient $httpClient)
     {
+        if ($this->isAbleToDiscoverRequestFactory()) {
+            throw new SkippingException('The builder does not throw an exception if it can automatically discover a request factory.');
+        }
+
         $this->setHttpClient($httpClient);
         $this->setBaseUrl('http://example.com/xapi/');
 
         $this->shouldThrow('\LogicException')->during('build');
     }
 
+    function it_can_build_the_client_when_it_is_able_to_discover_the_http_client_and_the_request_factory_without_configuring_them_explicitly()
+    {
+        if (!class_exists('\Http\Discovery\HttpClientDiscovery')) {
+            throw new SkippingException('The "\Http\Discovery\HttpClientDiscovery" class is required to let the builder auto discover the HTTP client and request factory.');
+        }
+
+        if (!$this->isAbleToDiscoverHttpClient()) {
+            throw new SkippingException('Unable to discover an HTTP client.');
+        }
+
+        if (!$this->isAbleToDiscoverRequestFactory()) {
+            throw new SkippingException('Unable to discover a request factory.');
+        }
+
+        $this->setBaseUrl('http://example.com/xapi/');
+
+        $this->build()->shouldReturnAnInstanceOf('\Xabbuh\XApi\Client\XApiClientInterface');
+    }
+
     function it_throws_an_exception_if_the_base_uri_is_not_configured(HttpClient $httpClient, RequestFactory $requestFactory)
     {
         $this->setHttpClient($httpClient);
         $this->setRequestFactory($requestFactory);
 
         $this->shouldThrow('\LogicException')->during('build');
     }
+
+    private function isAbleToDiscoverHttpClient()
+    {
+        try {
+            HttpClientDiscovery::find();
+
+            return true;
+        } catch (\Exception $e) {
+            return false;
+        }
+    }
+
+    private function isAbleToDiscoverRequestFactory()
+    {
+        try {
+            MessageFactoryDiscovery::find();
+
+            return true;
+        } catch (\Exception $e) {
+            return false;
+        }
+    }
 }

src/XApiClientBuilder.php

@@ -14,6 +14,8 @@
 use Http\Client\Common\Plugin\AuthenticationPlugin;
 use Http\Client\Common\PluginClient;
 use Http\Client\HttpClient;
+use Http\Discovery\HttpClientDiscovery;
+use Http\Discovery\MessageFactoryDiscovery;
 use Http\Message\Authentication\BasicAuth;
 use Http\Message\RequestFactory;
 use Xabbuh\XApi\Client\Request\Handler;
@@ -122,10 +124,24 @@ public function setOAuthCredentials($consumerKey, $consumerSecret, $token, $toke
      */
     public function build()
     {
+        if (null === $this->httpClient && class_exists('\Http\Discovery\HttpClientDiscovery')) {
+            try {
+                $this->httpClient = HttpClientDiscovery::find();
+            } catch (\Exception $e) {
+            }
+        }
+
         if (null === $httpClient = $this->httpClient) {
             throw new \LogicException('No HTTP client was configured.');
         }
 
+        if (null === $this->requestFactory && class_exists('\Http\Discovery\MessageFactoryDiscovery')) {
+            try {
+                $this->requestFactory = MessageFactoryDiscovery::find();
+            } catch (\Exception $e) {
+            }
+        }
+
         if (null === $this->requestFactory) {
             throw new \LogicException('No request factory was configured.');
         }