Extension:GoogleKnowledgeGraph

**MediaWiki extensions manual**
GoogleKnowledgeGraph; Release status: beta
Implementation	Tag, API
Description	The GoogleKnowledgeGraph extension automatically gets short summary from Google Knowledge Graph and adds it to a tooltip.
Author(s)	Urfiner (Nikolai Kochkin)
Latest version	0.1.0
MediaWiki	1.43
License	MIT License
Download	GitHub: project page; git repository URL [help]; commit history; ; Note:; No localisation updates are; provided by translatewiki.net.
	Hooks used OutputPageParserOutput; ParserFirstCallInit;

The GoogleKnowledgeGraph extension automatically gets short summary from Google Knowledge Graph and adds it to a tooltip.

The extension developed to help newcommers understand how to create a simple extension with frontend/backend (parser+api). The code of the extension is well-commented to make it easy to understand.

Production usage of the extension is not recommended.

Installation

Download and place the file(s) in a directory called GoogleKnowledgeGraph in your extensions/ folder.
Add the following code at the bottom of your LocalSettings.php file:
```
wfLoadExtension( 'GoogleKnowledgeGraph' );
```
Configure API key:
- Get Google API token here
- In LocalSettings.php set your key: $wgGoogleApiToken = 'your-google-token';
Setup language:$wgGoogleApiLanguage = 'en';
Done – Navigate to Special:Version on your wiki to verify that the extension is successfully installed.

Usage

Put something like that on your page:

<GoogleKnowledgeGraph query="Mario"/>

And save the page. After that hover cursor on the word "Mario" and see:

Production usage disclamer

The extension is not recommended for production usage:

Google Knowledge Graph provides only 100 000 requests for free per day.
1. For small wikis it is more than enough but on big ones the limit will be depleted quite soon.
2. Howewer, adding long-living cache may significantly improve the situation if for some reason you still want to use it in prod. There is a comment in code how a simple caching can be added.
It is not a big issue for English but Google Knowledge Graph supports search terms in Nominative case only.
1. In the future we can add something like that (synthax is not supported yet): <GoogleKnowledgeGraph query="Mario">visible text</GoogleKnowledgeGraph>.