[WIP] Schema URI support

src/JsonSchema/Constraints/Undefined.php

@@ -9,6 +9,8 @@
 
 namespace JsonSchema\Constraints;
 
+use JsonSchema\Validator;
+
 /**
  * The Undefined Constraints
  *
@@ -89,6 +91,9 @@ protected function validateCommonProperties($value, $schema = null, $path = null
     {
         // if it extends another schema, it must pass that schema as well
         if (isset($schema->extends)) {
+            if (is_string($schema->extends)) {
+                $schema->extends = $this->validateUri($schema->extends, $schema, $path, $i);
+            }
             $this->checkUndefined($value, $schema->extends, $path, $i);
         }
 
@@ -115,4 +120,14 @@ protected function validateCommonProperties($value, $schema = null, $path = null
             }
         }
     }
+
+    protected function validateUri($schemaUri = null, $schema, $path = null, $i = null)
+    {
+        $resolver = new \JsonSchema\Uri\UriResolver();
+
+        if ($resolver->isValid($schemaUri)) {
+            $schemaId = property_exists($schema, 'id') ? $schema->id : null;
+            return Validator::retrieveUri($resolver->resolve($schemaUri, $schemaId));
+        }
+    }
 }

src/JsonSchema/Exception/InvalidSchemaMediaTypeException.php

@@ -0,0 +1,17 @@
+<?php
+
+/*
+ * This file is part of the JsonSchema package.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace JsonSchema\Exception;
+
+/**
+ * Wrapper for the InvalidSchemaMediaType
+ */
+class InvalidSchemaMediaTypeException extends \RuntimeException
+{    
+}

src/JsonSchema/Exception/JsonDecodingException.php

@@ -0,0 +1,40 @@
+<?php
+
+/*
+ * This file is part of the JsonSchema package.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace JsonSchema\Exception;
+
+/**
+ * Wrapper for the JsonDecodingException
+ */
+class JsonDecodingException extends \RuntimeException
+{
+    public function __construct($code = JSON_ERROR_NONE, \Exception $previous = null)
+    {
+        switch ($code) {
+            case JSON_ERROR_DEPTH:
+                $message = 'The maximum stack depth has been exceeded';
+                break;
+            case JSON_ERROR_STATE_MISMATCH:
+                $message = 'Invalid or malformed JSON';
+                break;
+            case JSON_ERROR_CTRL_CHAR:
+                $message = 'Control character error, possibly incorrectly encoded';
+                break;
+            case JSON_ERROR_UTF8:
+                $message = 'Malformed UTF-8 characters, possibly incorrectly encoded';
+                break;
+            case JSON_ERROR_SYNTAX:
+                $message = 'The maximum stack depth has been exceeded';
+                break;
+            default:
+                $message = 'Syntax error';
+        }
+        parent::__construct($message, $code, $previous);
+    }
+}

src/JsonSchema/Exception/ResourceNotFoundException.php

@@ -0,0 +1,17 @@
+<?php
+
+/*
+ * This file is part of the JsonSchema package.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace JsonSchema\Exception;
+
+/**
+ * Wrapper for the ResourceNotFoundException
+ */
+class ResourceNotFoundException extends \RuntimeException
+{
+}

src/JsonSchema/Exception/UriResolverException.php

@@ -0,0 +1,17 @@
+<?php
+
+/*
+ * This file is part of the JsonSchema package.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace JsonSchema\Exception;
+
+/**
+ * Wrapper for the UriResolverException
+ */
+class UriResolverException extends \RuntimeException
+{
+}

src/JsonSchema/Uri/Retrievers/Curl.php

@@ -0,0 +1,82 @@
+<?php
+
+/*
+ * This file is part of the JsonSchema package.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace JsonSchema\Uri\Retrievers;
+
+use JsonSchema\Validator;
+
+use JsonSchema\Exception\ResourceNotFoundException;
+
+/**
+ * Tries to retrieve JSON schemas from a URI using cURL library
+ * 
+ * @author Sander Coolen <sander@jibber.nl> 
+ */
+class Curl implements UriRetrieverInterface
+{
+    protected $contentType;
+    protected $messageBody;
+
+    public function __construct()
+    {
+        if (!function_exists('curl_init')) {
+            throw new \RuntimeException("cURL not installed");
+        }
+    }
+
+    public function retrieve($uri)
+    {
+        $ch = curl_init();
+
+        curl_setopt($ch, CURLOPT_URL, $uri);
+        curl_setopt($ch, CURLOPT_HEADER, true);
+        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
+        curl_setopt($ch, CURLOPT_HTTPHEADER, array('Accept: ' . Validator::SCHEMA_MEDIA_TYPE));
+
+        $response = curl_exec($ch);
+        if (false === $response) {
+            throw new ResourceNotFoundException('JSON schema not found');
+        }
+
+        $this->fetchMessageBody($response);
+        $this->fetchContentType($response);
+
+        curl_close($ch);
+
+        return $this->messageBody;
+    }
+
+    /**
+     * @param string $response cURL HTTP response
+     */
+    private function fetchMessageBody($response)
+    {
+        preg_match("/(?:\r\n){2}(.*)$/ms", $response, $match);
+        $this->messageBody = $match[1];
+    }
+
+    /**
+     * @param string $response cURL HTTP response
+     * @return boolean Whether the Content-Type header was found or not
+     */
+    protected function fetchContentType($response)
+    {
+        if (0 < preg_match("/Content-Type:(\V*)/ims", $response, $match)) {
+            $this->contentType = trim($match[1]);
+
+            return true;
+        }
+        return false;
+    }
+
+    public function getContentType()
+    {
+        return $this->contentType;
+    }
+}

src/JsonSchema/Uri/Retrievers/FileGetContents.php

@@ -0,0 +1,73 @@
+<?php
+
+/*
+ * This file is part of the JsonSchema package.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace JsonSchema\Uri\Retrievers;
+
+use JsonSchema\Validator;
+
+/**
+ * Tries to retrieve JSON schemas from a URI using file_get_contents()
+ * 
+ * @author Sander Coolen <sander@jibber.nl> 
+ */
+class FileGetContents implements UriRetrieverInterface
+{
+    protected $contentType;
+    protected $messageBody;
+
+    public function retrieve($uri)
+    {
+        $context = stream_context_create(array(
+            'http' => array(
+                'method' => 'GET',
+                'header' => "Accept: " . Validator::SCHEMA_MEDIA_TYPE
+            )));
+
+        $response = file_get_contents($uri);
+        if (false === $response) {
+            throw new ResourceNotFoundException('JSON schema not found');
+        }
+
+        $this->messageBody = $response;
+        $this->fetchContentType($http_response_header);
+
+        return $this->messageBody;
+    }
+
+    /**
+     * @param array $headers HTTP Response Headers
+     * @return boolean Whether the Content-Type header was found or not
+     */
+    private function fetchContentType(array $headers)
+    {
+        foreach ($headers as $header) {
+            if ($this->contentType = self::getContentTypeMatchInHeader($header)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * @param string $header
+     * @return string|null
+     */
+    protected static function getContentTypeMatchInHeader($header)
+    {
+        if (0 < preg_match("/Content-Type:(\V*)/ims", $header, $match)) {
+            return trim($match[1]);
+        }
+    }
+
+    public function getContentType()
+    {
+        return $this->contentType;
+    }
+}

src/JsonSchema/Uri/Retrievers/UriRetrieverInterface.php

@@ -0,0 +1,22 @@
+<?php
+
+/*
+ * This file is part of the JsonSchema package.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace JsonSchema\Uri\Retrievers;
+
+/**
+ * Interface for URI retrievers
+ * 
+ * @author Sander Coolen <sander@jibber.nl> 
+ */
+interface UriRetrieverInterface
+{
+    public function retrieve($uri);
+
+    public function getContentType();
+}