Added support for using custom HTTP clients

.editorconfig

@@ -0,0 +1,11 @@
+# EditorConfig is awesome: http://EditorConfig.org
+
+# top-most EditorConfig file
+root = true
+
+# Unix-style newlines with a newline ending for every file
+# Indent with 4 spaces
+[php]
+end_of_line = lf
+indent_style = space
+indent_size = 4

.gitignore

@@ -0,0 +1,7 @@
+phpunit.xml
+composer.phar
+composer.lock
+vendor/
+build/
+.idea
+.DS_STORE

composer.json

@@ -2,7 +2,7 @@
     "name": "imsglobal/lti",
     "version" : "3.0.2",
     "description": "LTI Tool Provider Library",
-    "keywords": ["lti"],
+    "keywords": ["lti", "ims", "content-item", "edtech", "education", "lms"],
     "homepage": "https://www.imsglobal.org/lti",
     "type": "library",
     "license": "Apache-2.0",
@@ -19,5 +19,19 @@
         "psr-4": {
             "IMSGlobal\\LTI\\": "src/"
         }
+    },
+    "require-dev": {
+        "ext-curl": "*",
+        "phpunit/phpunit": "^5.6"
+    },
+    "autoload-dev":{
+        "psr-4": {
+            "IMSGlobal\\LTI\\Test\\": "tests/"
+        }
+    },
+    "scripts": {
+        "test": "phpunit",
+        "coverage": "phpunit --coverage-html=build/coverage",
+        "coverage-text": "phpunit --coverage-text"
     }
 }

phpunit.xml.dist

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit bootstrap="./vendor/autoload.php"
+         forceCoversAnnotation="true">
+
+    <testsuites>
+        <testsuite>
+            <directory suffix="Test.php">tests/</directory>
+        </testsuite>
+    </testsuites>
+
+    <filter>
+        <whitelist addUncoveredFilesFromWhitelist="true">
+            <directory suffix=".php">src</directory>
+        </whitelist>
+    </filter>
+
+    <php>
+        <server name="TEST_SERVER_PORT" value="9999"/>
+    </php>
+
+</phpunit>

src/HTTP/Client.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace IMSGlobal\LTI\HTTP;
+
+use IMSGlobal\LTI\HTTPMessage;
+
+/**
+ * An HTTP client for sending the HTTP messages.
+ *
+ * @author  Stephen P Vickers <[email protected]>
+ * @copyright  IMS Global Learning Consortium Inc
+ * @date  2016
+ * @version 3.0.0
+ * @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0
+ */
+interface Client
+{
+
+    /**
+     * Send the provided HTTPMessage and then updates it with the response data.
+     * 
+     * @param HTTPMessage $message The HTTP message to send
+     * @return bool If successful, returns true
+     */
+    public function send(HTTPMessage $message);
+
+}

src/HTTP/CurlClient.php

@@ -0,0 +1,69 @@
+<?php
+
+namespace IMSGlobal\LTI\HTTP;
+
+use IMSGlobal\LTI\HTTPMessage;
+
+/**
+ * Sends HTTP messages with cURL.
+ *
+ * @author  Stephen P Vickers <[email protected]>
+ * @copyright  IMS Global Learning Consortium Inc
+ * @date  2016
+ * @version 3.0.0
+ * @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0
+ */
+class CurlClient implements Client
+{
+
+    /**
+     * @inheritdoc
+     */
+    public function send(HTTPMessage $message)
+    {
+        $message->ok = false;
+
+        $resp = '';
+        $ch = curl_init();
+        curl_setopt($ch, CURLOPT_URL, $message->url);
+        if (!empty($message->requestHeaders)) {
+            curl_setopt($ch, CURLOPT_HTTPHEADER, $message->requestHeaders);
+        } else {
+            curl_setopt($ch, CURLOPT_HEADER, 0);
+        }
+        if ($message->method === 'POST') {
+            curl_setopt($ch, CURLOPT_POST, true);
+            curl_setopt($ch, CURLOPT_POSTFIELDS, $message->request);
+        } else if ($message->method !== 'GET') {
+            curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $message->method);
+            if (!is_null($message->request)) {
+                curl_setopt($ch, CURLOPT_POSTFIELDS, $message->request);
+            }
+        }
+        curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
+        curl_setopt($ch, CURLINFO_HEADER_OUT, true);
+        curl_setopt($ch, CURLOPT_HEADER, true);
+        $chResp = curl_exec($ch);
+        $message->ok = $chResp !== false;
+        if ($message->ok) {
+            $chResp = str_replace("\r\n", "\n", $chResp);
+            $chRespSplit = explode("\n\n", $chResp, 2);
+            if ((count($chRespSplit) > 1) && (substr($chRespSplit[1], 0, 5) === 'HTTP/')) {
+                $chRespSplit = explode("\n\n", $chRespSplit[1], 2);
+            }
+            $message->responseHeaders = $chRespSplit[0];
+            $resp = $chRespSplit[1];
+            $message->status = curl_getinfo($ch, CURLINFO_HTTP_CODE);
+            $message->ok = $message->status < 400;
+            if (!$message->ok) {
+                $message->error = curl_error($ch);
+            }
+        }
+        $message->requestHeaders = str_replace("\r\n", "\n", curl_getinfo($ch, CURLINFO_HEADER_OUT));
+        curl_close($ch);
+        $message->response = $resp;
+
+        return $message->ok;
+    }
+
+}

src/HTTP/StreamClient.php

@@ -0,0 +1,55 @@
+<?php
+
+namespace IMSGlobal\LTI\HTTP;
+
+use IMSGlobal\LTI\HTTPMessage;
+
+/**
+ * Sends HTTP messages with streams via fopen.
+ *
+ * @author  Stephen P Vickers <[email protected]>
+ * @copyright  IMS Global Learning Consortium Inc
+ * @date  2016
+ * @version 3.0.0
+ * @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0
+ */
+class StreamClient implements Client
+{
+
+    /**
+     * @inheritdoc
+     */
+    public function send(HTTPMessage $message)
+    {
+        $message->ok = false;
+
+        // Prepare options for the HTTP context.
+        $opts = array(
+            'method' => $message->method,
+            'content' => $message->request
+        );
+        if (!empty($message->requestHeaders)) {
+            $opts['header'] = $message->requestHeaders;
+        }
+
+        // Send the request.
+        $http_response_header = null;
+        $context = stream_context_create(['http' => $opts]);
+        $stream = @fopen($message->url, 'rb', false, $context);
+        if ($stream) {
+            $message->response = @stream_get_contents($stream);
+            fclose($stream);
+        }
+
+        // Read the headers to get the status.
+        if ($http_response_header) {
+            $message->responseHeaders = implode("\n", $http_response_header);
+            $parts = explode(' ', $message->responseHeaders, 3);
+            $message->status = $parts[1];
+            $message->ok = $message->status < 400;
+        }
+
+        return $message->ok;
+    }
+
+}