Resolve "OER-Campus: Großer schwarzer Kasten"

Closes #1384

Merge request studip/studip!906

app/views/oer/market/details.php

@@ -25,8 +25,10 @@
                src="<?= htmlReady($url) ?>"></audio>
     </div>
 <? elseif ($material->isPDF()) : ?>
-    <iframe src="<?= htmlReady($url) ?>"
-            class="lernmarktplatz_player"></iframe>
+    <? if ($material->isPDFInlineDisplayable()) : ?>
+        <iframe src="<?= htmlReady($url) ?>"
+                class="lernmarktplatz_player"></iframe>
+    <? endif ?>
 <? elseif ($material['front_image_content_type']) : ?>
     <div style="background-image: url('<?= htmlReady($material->getLogoURL()) ?>');" class="lernmarktplatz_player image"></div>
 <? endif ?>

lib/models/OERMaterial.php

@@ -305,6 +305,21 @@ class OERMaterial extends SimpleORMap
         return $this['content_type'] === "application/pdf";
     }
 
+    public function isPDFInlineDisplayable()
+    {
+        if (!$this->isPDF()) {
+            return false;
+        }
+        $url = $this->getDownloadUrl();
+        $headers = get_headers($url, true);
+        if ($headers['Content-Disposition']
+            && substr($headers['Content-Disposition'], 0, strlen('attachment')) === 'attachment') {
+            //in this case the server forces to download the document and we cannot display it in an iframe:
+            return false;
+        }
+        return true;
+    }
+
     protected function getFileEnding()
     {
         return pathinfo($this["filename"], PATHINFO_EXTENSION);

resources/assets/stylesheets/scss/oer.scss

@@ -396,7 +396,8 @@ ul.reviews, ol.reviews {
         width: 840px;
         max-width: 100%;
         box-sizing: border-box;
-        min-height: 200px;
+        height: 200px;
+        max-height: 200px;
         overflow: hidden;
         .intro {
             display: flex;