Improve error handling for loading Random Rules

Provide better error handling when loading Random Rules and create a
basic placeholder for other branches to enhance with any custom
headers they want to include.

Author: cpeel

pinc/RandomRule.inc

@@ -202,10 +202,31 @@ class RandomRule
         // delete all existing random rules for this ($document, $langcode)
         RandomRule::delete_rules($document, $langcode);
 
-        if (($fhandle = fopen($url, "rt")) === false) {
+        // basic HTTP contexts for the fopen -- mostly a placeholder for
+        // customization in other branches who want to set specific headers
+        $context_opts = [
+            'http' => [
+                'method' => "GET",
+            ],
+        ];
+
+        $context = stream_context_create($context_opts);
+        if (($fhandle = fopen($url, "rt", context: $context)) === false) {
             throw new RuntimeException(sprintf(_("Failed to load rules from %s."), $url));
         }
 
+        $meta_data = stream_get_meta_data($fhandle);
+        $status_line = $meta_data["wrapper_data"][0] ?? "";
+        if (! preg_match("/HTTP\/\S+\s+200\b/", $status_line)) {
+            throw new RuntimeException(
+                sprintf(
+                    "%s %s",
+                    sprintf(_("Failed to load rules from %s."), $url),
+                    $status_line
+                )
+            );
+        }
+
         $anchor = $subject = $rule = "";
         $in_rule = false;
         while ($line = fgets($fhandle)) {

tools/site_admin/manage_random_rules.php

@@ -23,9 +23,14 @@
 
 // do POST actions
 if ($action == 'update') {
-    RandomRule::reload_rules($url, $document, $langcode);
-    // TRANSLATORS: %3$s is a URL
-    echo "<p class='warning'>" . sprintf(_('Loaded rules for document %1$s and language %2$s from %3$s.'), RandomRule::$document_values[$document], $langcode, $url) . "</p>";
+    try {
+        RandomRule::reload_rules($url, $document, $langcode);
+
+        // TRANSLATORS: %3$s is a URL
+        echo "<p class='warning'>" . sprintf(_('Loaded rules for document %1$s and language %2$s from %3$s.'), RandomRule::$document_values[$document], $langcode, $url) . "</p>";
+    } catch (RuntimeException $exception) {
+        echo "<p class='error'>" . $exception->getMessage() . "</p>";
+    }
 } elseif ($action == 'delete') {
     RandomRule::delete_rules($document, $langcode);
     echo "<p class='warning'>" . sprintf(_('Deleted rules for document %1$s and language %2$s.'), RandomRule::$document_values[$document], $langcode) . "</p>";