sends an Accept header when fetching posts

lib/XRay/Fetcher.php

@@ -70,6 +70,9 @@ class Fetcher {
     }
 
     $headers = [];
+
+    $headers[] = 'Accept: text/html, application/json, application/xml, text/xml';
+
     if(isset($opts['token']))
       $headers[] = 'Authorization: Bearer ' . $opts['token'];
 
@@ -84,16 +87,34 @@ class Fetcher {
       ];
     }
 
+    // Show an error if the content type returned is not a recognized type
+    $format = null;
+    if(isset($result['headers']['Content-Type']) && is_string($result['headers']['Content-Type'])) {
+      $type = new MediaType($result['headers']['Content-Type']);
+      $format = $type->format;
+    }
+
+    if(!$format ||
+      !in_array($format, ['html', 'json', 'xml'])) {
+        return [
+          'error' => 'invalid_content',
+          'error_description' => 'The server did not return a recognized content type',
+          'content_type' => $result['headers']['Content-Type'],
+          'url' => $result['url'],
+          'code' => $result['code']
+        ];
+    }
+
     if(trim($result['body']) == '') {
       if($result['code'] == 410) {
         // 410 Gone responses are valid and should not return an error
-        return $this->respond($response, 200, [
+        return [
           'data' => [
-            'type' => 'unknown'
+            'type' => 'deleted'
           ],
           'url' => $result['url'],
           'code' => $result['code']
-        ]);
+        ];
       }
 
       return [

lib/XRay/MediaType.php

@@ -0,0 +1,40 @@
+<?php
+namespace p3k\XRay;
+
+class MediaType {
+
+  public $type;
+  public $subtype;
+  public $format;
+  public $charset;
+
+  // Parse a media type into component parts: type, subtype, format, charset
+  // e.g. "application/json" => type: application, subtype: json, format: json
+  // "application/ld+json" => type: application, subtype: "ld+json", format: json
+  public function __construct($string) {
+    if(strstr($string, ';')) {
+      list($type, $parameters) = explode(';', $string, 2);
+
+      $parameters = explode(';', $parameters);
+      foreach($parameters as $p) {
+        list($k, $v) = explode('=', trim($p));
+        if($k == 'charset')
+          $this->charset = $v;
+      }
+    } else {
+      $type = $string;
+    }
+
+    list($type, $subtype) = explode('/', $type);
+
+    $this->type = $type;
+    $this->subtype = $subtype;
+    $this->format = $subtype;
+
+    if(strstr($subtype, '+')) {
+      list($a, $b) = explode('+', $subtype, 2);
+      $this->format = $b;
+    }
+  }
+
+}

tests/MediaTypeTest.php

@@ -0,0 +1,44 @@
+<?php
+class MediaTypeTest extends PHPUnit_Framework_TestCase {
+
+  public function testParseTextHtml() {
+    $type = new p3k\XRay\MediaType('text/html');
+    $this->assertEquals('text', $type->type);
+    $this->assertEquals('html', $type->subtype);
+    $this->assertEquals('html', $type->format);
+    $this->assertEquals(null, $type->charset);
+  }
+
+  public function testParseTextHtmlUtf8() {
+    $type = new p3k\XRay\MediaType('text/html; charset=UTF-8');
+    $this->assertEquals('text', $type->type);
+    $this->assertEquals('html', $type->subtype);
+    $this->assertEquals('html', $type->format);
+    $this->assertEquals('UTF-8', $type->charset);
+  }
+
+  public function testParseTextHtmlUtf8Extra() {
+    $type = new p3k\XRay\MediaType('text/html; hello=world; charset=UTF-8');
+    $this->assertEquals('text', $type->type);
+    $this->assertEquals('html', $type->subtype);
+    $this->assertEquals('html', $type->format);
+    $this->assertEquals('UTF-8', $type->charset);
+  }
+
+  public function testParseApplicationJson() {
+    $type = new p3k\XRay\MediaType('application/json');
+    $this->assertEquals('application', $type->type);
+    $this->assertEquals('json', $type->subtype);
+    $this->assertEquals('json', $type->format);
+    $this->assertEquals(null, $type->charset);
+  }
+
+  public function testParseApplicationJsonFeed() {
+    $type = new p3k\XRay\MediaType('application/feed+json');
+    $this->assertEquals('application', $type->type);
+    $this->assertEquals('feed+json', $type->subtype);
+    $this->assertEquals('json', $type->format);
+    $this->assertEquals(null, $type->charset);
+  }
+
+}