Content-Negotiation with the help of Renderer and Formatters

Lib/Formatter/Formatter.php

@@ -0,0 +1,76 @@
+<?php
+
+namespace BSR\Lib\Formatter;
+
+abstract class Formatter {
+    private static $formats = array();
+
+    /**
+     * @param array $formats New available formats, array(mimetype => class)
+     */
+    protected static function registerFormats(array $formats) {
+        foreach($formats as $f) {
+            self::$formats[$f] = get_called_class();
+        }
+    }
+
+    /**
+     * @return Formatter The formatter to use for this request
+     */
+    public static function getFormatter() {
+        self::loadFormatters();
+        $format = self::getFormatFromHeader();
+
+        return new $format();
+    }
+
+    /**
+     * Load all formatters in the current directory
+     */
+    private static function loadFormatters() {
+        preg_match('/(.+)\\\([a-zA-Z0-9]+)/', get_called_class(), $parts);
+        $us = $parts[2];
+        $namespace = $parts[1];
+
+        $base = __DIR__.'/';
+        $ext = '.php';
+        $files = glob(sprintf('%s%s%s', $base, '*', $ext));
+        foreach($files as $f) {
+            $c = str_replace(array($base, $ext), '', $f);
+            if($c !== $us) {
+                $c = $namespace.'\\'.$c;
+                call_user_func(array($c, 'init'));
+            }
+        }
+    }
+
+    /**
+     * @return string The class name to instantiate in accord to the Accept header
+     */
+    private static function getFormatFromHeader() {
+        if(isset($_SERVER['HTTP_ACCEPT'])) {
+            $formats = array_map(function($f) {
+                $parts = explode(';', $f);
+                $parts[1] = (isset($parts[1]) ? (float) preg_replace('/[^0-9\.]/', '', $parts[1]) : 1.0) * 100;
+                return $parts;
+            }, explode(',', $_SERVER['HTTP_ACCEPT']));
+
+            usort($formats, function($a, $b) { return $b[1]  - $a[1]; });
+
+            foreach($formats as $f) {
+                if(isset(self::$formats[$f[0]])) {
+                    return self::$formats[$f[0]];
+                }
+            }
+
+        }
+
+        return 'BSR\Lib\Formatter\Json';
+    }
+
+    /**
+     * Output the content for the given data
+     * @param $array data
+     */
+    abstract public function render($data);
+}

Lib/Formatter/Html.php

@@ -0,0 +1,80 @@
+<?php
+
+namespace BSR\Lib\Formatter;
+
+class Html extends Formatter {
+    protected static function init() {
+        self::registerFormats(array(
+            'application/xhtml+xml',
+            'text/html',
+        ));
+    }
+
+    private function result($data) {
+        // the format is array('result' => array('funcname' => DATA))
+        // so take the first element of the 'result' array
+        $data = reset($data['result']);
+
+        $first = reset($data);
+        $single = ! is_array($first);
+
+        $content = '<table><thead>';
+        if($single) {
+            $content .= "<tr><th>Field</th><th>Value</th></tr>";
+        } else {
+            $content .= '<tr>';
+            foreach(array_keys($first) as $k) {
+                $content .= "<th>$k</th>";
+            }
+            $content .= '</tr>';
+        }
+        $content .= '</thead><tbody>';
+        if($single) {
+            foreach($data as $k => $v) {
+                $content .= "<tr><th>$k</th><td>".print_r($v, true)."</td></tr>";
+            }
+        } else {
+            foreach($data as $row) {
+                $content .= '<tr>';
+                foreach($row as $col) {
+                    $content .= '<td>'.print_r($col, true).'</td>';
+                }
+                $content .= '</tr>';
+            }
+        }
+        $content .= '</tbody></table>';
+
+        return $content;
+    }
+
+    private function error($data) {
+        $code = $data['error']['code'];
+        $name = $data['error']['name'];
+        $msg = $data['error']['reason'];
+
+        return '<h1>An error occured</h1>'.
+                "<h2>[$code] $name</h2>".
+                "<p>$msg</p>";
+    }
+
+    private function failure($data) {
+        $code = $data['failure']['code'];
+        $name = $data['failure']['reason'];
+
+        return '<h1>A failure occured</h1>'.
+                "<h2>[$code] $name</h2>";
+    }
+
+    public function render($data)
+    {
+        $type = key($data);
+
+        if (method_exists($this, $type)) {
+            $content = call_user_func_array(array($this, $type), array($data));
+        } else {
+            $content = '<h1>Unable to render this</h1>';
+        }
+
+        echo $content;
+    }
+}

Lib/Formatter/Json.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace BSR\Lib\Formatter;
+
+class Json extends Formatter {
+    protected static function init() {
+        self::registerFormats(array(
+            'application/json',
+            'application/x-json',
+        ));
+    }
+
+    public function render($data) {
+        echo json_encode($data);
+    }
+}
+

Lib/Formatter/Text.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace BSR\Lib\Formatter;
+
+class Text extends Formatter {
+    protected static function init() {
+        self::registerFormats(array('text/plain'));
+    }
+
+    public function render($data) {
+        print_r($data);
+    }
+}

Lib/Formatter/Xml.php

@@ -0,0 +1,17 @@
+<?php
+
+namespace BSR\Lib\Formatter;
+
+class Xml extends Formatter {
+    protected static function init() {
+        self::registerFormats(array(
+            'text/xml',
+            'application/xml',
+            'application/x-xml',
+        ));
+    }
+
+    public function render($data) {
+        throw new \RuntimeException('Not implemented yet.');
+    }
+}

Lib/Renderer.php

@@ -0,0 +1,29 @@
+<?php
+
+namespace BSR\Lib;
+
+use BSR\Lib\Formatter\Formatter;
+
+class Renderer {
+    private static $statusMessages = array(
+        200 => 'Ok',
+        400 => 'Bad request',
+        404 => 'Not Found',
+        403 => 'Not Authorized',
+        500 => 'Server Error',
+    );
+
+    public function __construct() {
+        ob_start();
+    }
+
+    public function render($status, $data) {
+        header(sprintf('HTTP/1.0 %s %s', $status, self::$statusMessages[$status]));
+
+        ob_clean();
+        flush();
+
+        $formatter = Formatter::getFormatter();
+        $formatter->render($data);
+    }
+}

Lib/WebService.php

@@ -3,6 +3,7 @@
 namespace BSR\Lib;
 
 use BSR\Lib\Exception\WebException;
+use BSR\Lib\Renderer;
 
 abstract class WebService
 {
@@ -30,6 +31,8 @@ abstract class WebService
 
     public function Run()
     {
+        $renderer = new Renderer();
+
         $this->log("------------------");
         $this->log("Start request", 1, true);
         $data = array();
@@ -39,19 +42,22 @@ abstract class WebService
             $data["result"][$this->func] = $result;
         } catch (WebException $e) {
             $data["error"]["code"] = $e->getCode();
-            $data["error"]["name"] = $e->getName();
             $data["error"]["reason"] = $e->getMessage();
+            $data["error"]["name"] = $e->getName();
             $this->status = 400;
 
             $this->log(sprintf("Error : [%s] %s", $e->getCode(), $e->getName()));
         } catch (\Exception $e) {
-            $data["failure"]["message"] = $e->getMessage();
+            $data["failure"]["code"] = $e->getCode();
+            $data["failure"]["reason"] = $e->getMessage();
             $this->status = 500;
 
             $this->log(sprintf("Failure : %s", $e->getMessage()));
         }
 
-        $this->Send($data);
+        $this->log("Data: ".print_r($data, true), 2);
+
+        $renderer->render($this->status, $data);
 
         $this->log("Request finished", 1, true);
         $this->log("------------------\n\n");
@@ -63,7 +69,6 @@ abstract class WebService
 
     private function Call()
     {
-        ob_start();
         session_save_path(Configuration::get('session.save_path'));
         session_start();
 
@@ -100,23 +105,4 @@ abstract class WebService
         $this->log("Params: ".print_r($params, true), 2);
         return call_user_func_array(array($this, $this->func), $params);
     }
-
-    private function Send(array $data)
-    {
-        static $status_messages = array(
-            200 => 'Ok',
-            400 => 'Bad request',
-            404 => 'Not Found',
-            403 => 'Not Authorized',
-            500 => 'Server Error',
-        );
-
-        header(sprintf('HTTP/1.0 %s %s', $this->status, $status_messages[$this->status]));
-
-        ob_clean();
-        flush();
-
-        $this->log("Data: ".print_r($data, true), 2);
-        echo json_encode($data);
-    }
 }