Add editing of feed URL (#4)

- Move feed-specific database calls to Feed class
- Detect when feed items have been updated
- Add const keys for $_REQUEST values

src/public/feed.php

@@ -9,20 +9,35 @@ include '../start.php';
 
 Security::verifyUser();
 
+$feedId = array_key_exists('id', $_GET) ? $_GET['id'] : '';
+$db     = Data::getConnection();
+
 if ($_SERVER['REQUEST_METHOD'] == 'POST') {
-    // TODO: get feed, add if new, reject if existing but not owned by this user, update otherwise
-    $result = Feed::add($_POST['url']);
-    if (array_key_exists('ok', $result)) {
-        add_message('INFO', 'Feed added successfully');
+    $isNew = $_POST['id'] == 'new';
+    if ($isNew) {
+        $result = Feed::add($_POST['url'], $db);
     } else {
-        add_message('ERROR', $result['error']);
+        $toEdit = Data::retrieveFeedById($_POST['id'], $db);
+        $result = $toEdit ? Feed::update($toEdit, $_POST['url'], $db) : [ 'error' => "Feed {$_POST['id']} not found" ];
     }
-    $feed = [ 'id' => $_POST['id'], 'url' => $_POST['url'] ];
-    $title = 'TODO';
-} else {
-    // TODO: Retrieve feed by ID if not new
+    if (array_key_exists('ok', $result)) {
+        add_info('Feed saved successfully');
+        $feedId = $isNew ? $result['ok'] : $_POST['id'];
+    } else {
+        add_error($result['error']);
+    }
+}
+
+if ($feedId == 'new') {
     $feed = [ 'id' => $_GET['id'], 'url' => '' ];
     $title = 'Add RSS Feed';
+} else {
+    $feed = Data::retrieveFeedById((int) $feedId, $db);
+    if (!$feed) {
+        http_response_code(404);
+        die();
+    }
+    $title = 'Edit RSS Feed';
 }
 
 page_head($title); ?>
@@ -38,3 +53,4 @@ page_head($title); ?>
     </form>
 </article><?php
 page_foot();
+$db->close();

src/public/index.php

@@ -9,8 +9,6 @@ include '../start.php';
 
 Security::verifyUser();
 
-page_head('Welcome');
-?>
-
-<?php
+page_head('Welcome'); ?>
+<p>Unread items go here</p><?php
 page_foot();