update old placeholder images on upgrade

Signed-off-by: matdave <[email protected]>

_build/config.json

@@ -131,7 +131,8 @@
       "after": [
         "resolve.synctables.php",
         "resolve.defaulttheme.php",
-        "resolve.migration.php"
+        "resolve.migration.php",
+        "resolve.placehold.php"
       ]
     }
   }

_build/resolvers/resolve.placehold.php

@@ -0,0 +1,30 @@
+<?php
+
+if ($object->xpdo) {
+    switch ($options[xPDOTransport::PACKAGE_ACTION]) {
+        case xPDOTransport::ACTION_UPGRADE:
+            /** @var modX $modx */
+            $modx =& $object->xpdo;
+            $c = $modx->newQuery('FredElement');
+            $c->where(['image:LIKE' => 'https://via.placeholder.com/%']);
+            $elements = $modx->getCollection('FredElement', $c);
+            foreach ($elements as $element) {
+                $image = $element->get('image');
+                $image = str_replace('https://via.placeholder.com/', 'https://placehold.co/', $image);
+                $element->set('image', $image);
+                $element->save();
+            }
+
+            $c = $modx->newQuery('FredBlueprint');
+            $c->where(['image:LIKE' => 'https://via.placeholder.com/%']);
+            $blueprints = $modx->getCollection('FredBlueprint', $c);
+            foreach ($blueprints as $blueprint) {
+                $image = $blueprint->get('image');
+                $image = str_replace('https://via.placeholder.com/', 'https://placehold.co/', $image);
+                $blueprint->set('image', $image);
+                $blueprint->save();
+            }
+            break;
+    }
+}
+return true;