Prevent adding item if there are no categories or locations (Close #4)

lang/en_us.php

@@ -86,5 +86,6 @@ define("STRINGS", [
     "only showing understocked" => "Only showing understocked items.",
     "show all items" => "Show all items",
     "missing name" => "You need to enter a name.",
-    "use the dropdowns" => "Whoops, you need to use the category and location autocomplete boxes."
+    "use the dropdowns" => "Whoops, you need to use the category and location autocomplete boxes.",
+    "make categories and locations" => "Please create at least one category and location before adding an item."
 ]);

lang/messages.php

@@ -80,5 +80,9 @@ define("MESSAGES", [
     "use_the_drop_luke" => [
         "string" => "use the dropdowns",
         "type" => "danger"
+    ],
+    "noloccat" => [
+        "string" => "make categories and locations",
+        "type" => "info"
     ]
 ]);

pages/edititem.php

@@ -5,6 +5,11 @@ require_once __DIR__ . "/../lib/userinfo.php";
 
 redirectifnotloggedin();
 
+if ($database->count("locations") == 0 || $database->count("categories") == 0) {
+    header('Location: app.php?page=items&msg=noloccat');
+    die();
+}
+
 $itemdata = [
     'name' => '',
     'catid' => '',
@@ -55,6 +60,7 @@ if (!is_empty($VARS['id'])) {
     } else {
         // item id is invalid, redirect to a page that won't cause an error when pressing Save
         header('Location: app.php?page=edititem');
+        die();
     }
 }
 ?>