Issue #964: Allow relative paths in IIIF manifests. (#965)

* Issue #964: Allow relative paths in IIIF manifests.

* Address PHPCS error.

* Fix missing use statement.

modules/islandora_iiif/config/schema/islandora_iiif.schema.yml

@@ -5,6 +5,9 @@ islandora_iiif.settings:
     iiif_server:
       type: string
       label: 'IIIF Server Url'
+    use_relative_paths:
+    type: boolean
+    label: 'Use relative paths in manifest.'
 
 views.style.iiif_manifest:
   type: views_style

modules/islandora_iiif/src/Form/IslandoraIIIFConfigForm.php

@@ -73,6 +73,14 @@ class IslandoraIIIFConfigForm extends ConfigFormBase {
       '#description' => $this->t('Please enter the image server location without trailing slash. e.g. http://www.example.org/iiif/2.'),
       '#default_value' => $config->get('iiif_server'),
     ];
+
+    $form['use_relative_paths'] = [
+      '#type' => 'checkbox',
+      '#title' => $this->t("Use relative file paths in manifest."),
+      '#description' => $this->t("Check this if your IIIF Server is configured to access files locally. If unchecked, the absolute URL will be given and the IIIF server will make requests to this site to retrieve images."),
+      '#default_value' => $config->get('use_relative_paths'),
+    ];
+
     return parent::buildForm($form, $form_state);
   }
 
@@ -99,6 +107,7 @@ class IslandoraIIIFConfigForm extends ConfigFormBase {
 
     $this->config('islandora_iiif.settings')
       ->set('iiif_server', $form_state->getValue('iiif_server'))
+      ->set('use_relative_paths', $form_state->getValue('use_relative_paths'))
       ->save();
   }
 

modules/islandora_iiif/src/Plugin/views/style/IIIFManifest.php

@@ -229,7 +229,13 @@ class IIIFManifest extends StylePluginBase {
 
           // Create the IIIF URL for this file
           // Visiting $iiif_url will resolve to the info.json for the image.
-          $file_url = $image->entity->createFileUrl(FALSE);
+          if ($this->iiifConfig->get('use_relative_paths')) {
+            $file_url = ltrim($image->entity->createFileUrl(TRUE), '/');
+          }
+          else {
+            $file_url = $image->entity->createFileUrl(FALSE);
+          }
+
           $mime_type = $image->entity->getMimeType();
           $iiif_url = rtrim($iiif_address, '/') . '/' . urlencode($file_url);