First cut of item-with-feed and list impl

- Add strict types to all files
- Convert many queries to document commands

src/lib/Data.php

@@ -1,7 +1,9 @@
-<?php
+<?php declare(strict_types=1);
+
 namespace FeedReaderCentral;
 
 use BitBadger\Documents\DocumentException;
+use BitBadger\Documents\Field;
 use BitBadger\Documents\SQLite\Configuration;
 use BitBadger\Documents\SQLite\Custom;
 use BitBadger\Documents\SQLite\Definition;
@@ -77,6 +79,59 @@ class Data
         $db->close();
     }
 
+    /**
+     * Create a JSON field comparison to find bookmarked items
+     *
+     * @param string $qualifier The table qualifier to include (optional; defaults to no qualifier)
+     * @return Field A field that will find bookmarked items
+     */
+    public static function bookmarkField(string $qualifier = ''): Field
+    {
+        $bookField = Field::EQ('is_bookmarked', 1, '@book');
+        $bookField->qualifier = $qualifier;
+        return $bookField;
+    }
+
+    /**
+     * Create a JSON field comparison to find items for a given feed
+     *
+     * @param int $feedId The ID of the feed for which items should be retrieved
+     * @param string $qualifier The table qualifier to include (optional; defaults to no qualifier)
+     * @return Field A field to find items for the give feed
+     */
+    public static function feedField(int $feedId, string $qualifier = ''): Field
+    {
+        $feedField = Field::EQ(Configuration::idField(), $feedId, '@feed');
+        $feedField->qualifier = $qualifier;
+        return $feedField;
+    }
+
+    /**
+     * Create a JSON field comparison to find unread items
+     *
+     * @param string $qualifier The table qualifier to include (optional; defaults to no qualifier)
+     * @return Field A field to find unread items
+     */
+    public static function unreadField(string $qualifier = ''): Field
+    {
+        $readField = Field::EQ('is_read', 0, '@read');
+        $readField->qualifier = $qualifier;
+        return $readField;
+    }
+
+    /**
+     * Create a JSON field comparison to find items belonging to feeds to which the given user is subscribed
+     *
+     * @param string $qualifier The table qualifier to include (optional; defaults to no qualifier)
+     * @return Field A field to find feeds belonging to the given user
+     */
+    public static function userIdField(string $qualifier = ''): Field
+    {
+        $userField = Field::EQ('user_id', $_SESSION[Key::USER_ID], '@user');
+        $userField->qualifier = $qualifier;
+        return $userField;
+    }
+
     /**
      * Parse/format a date/time from a string
      *