> ## Documentation Index
> Fetch the complete documentation index at: https://doc.lucidworks.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Appkit SDK 4.2.3 Release Notes

[localhost link]: http://localhost:3000/docs/4/app-studio/release-notes/appkit/4.2.3-release-notes

[mintlify link]: https://doc.lucidworks.com/docs/4/app-studio/release-notes/appkit/4.2.3-release-notes

[old doc.lw link]: https://doc.lucidworks.com/app-studio/4.2/975

**Release date:** 25 March 2019

## Upgrading to this version

In apps created with prior versions of Fusion App Studio, you can **Upgrade Appkit in Existing Apps**.

<Accordion title="Upgrade Appkit in Existing Apps">
  When you create an Appkit webapp, it uses a specific version of Appkit. Appkit releases occur independently of App Studio releases.

  You can upgrade web apps to use the latest version of Appkit.

  **How to upgrade**

  1. Stop the app.
  2. In the `package.json` file at the root of your project, update the `appkit-ui` dependency to the latest Appkit version, for example:

     ```json theme={"dark"}
     "appkit-ui": "http://appkit.lucidworks.com/repo/4.2.0/appkit-ui.tar.gz",
     ```
  3. In the `pom.xml` file at the root of your project, update the value of the `parent.version` property to the latest Appkit version, for example:

     ```xml theme={"dark"}
         <parent>
             <groupId>twigkit</groupId>
             <artifactId>twigkit.app.js</artifactId>
             <version>4.2.0</version>
         </parent>
     ```
  4. Upgrade the Appkit Social module, if required.
  5. Perform any additional upgrade steps that are required for a specific Appkit upgrade. See the [Appkit Release Notes](/docs/4/app-studio/release-notes/appkit/overview) for more information.
  6. Start the app.
</Accordion>

## New features and improvements

You can add the optional `search-wildcard` attribute to the `search-facet` directive to specify whether Appkit performs a wildcard search within facet names and, if it does, how it attaches the wildcard character(s) to the terms that users enter.

A wildcard character matches zero or more characters where it is placed. For example, `computer*` would match the facets `computers` and `computer accessories`. This wildcard is often represented as an asterisk (\*).

The `search-wildcard` attribute can have these values:

| Value             | Description                                                                                                                    |
| ----------------- | ------------------------------------------------------------------------------------------------------------------------------ |
| `left`            | Adds a wildcard prefix to facet search terms, for example, `term` (entered) becomes `*term` (used to search).                  |
| `right`           | Adds a wildcard suffix to facet search terms, for example, `term` (entered) becomes `term*` (used to search).                  |
| `both`  (default) | Adds both a wildcard prefix and suffix to facet search terms, for example, `term` (entered) becomes `*term*` (used to search). |
| `none`            | Adds no wildcard to facet search terms (exact match).                                                                          |

## Fixed issues

This release contains these fixes:

* Previously, some click signals caused HTTP 401 errors. These are now sent correctly.

* Saved queries with page parameters now work correctly.