Hub

This is aWeb hub: it let's you craft URLs to go from anorigin to adestination on the web, at the condition that you provide enough information on those points to be identified withinWikidata. It works primarily around Wikimedia sites, but given the amount Wikidata knows about the web at large, it can get you pretty far! And if you don't know where you want to go, that's ok too: this will just bring you to the closest Wikipedia article.

Target audience:

• Wikidata-centered tools developers
• URL craftmen: people who like to browse the web by tweaking URLs

A few examples to catch your interest:

we can now link to Wikipedia articles about a concept in the user's favorite language:

• from a Wikidata id:/Q3
• from an article title from the English Wikipedia:/Lyon
• or another Wikipedia:/zh:阿根廷
• or any Wikimedia project:/frwikivoyage:Allemagne
• or any external id known by Wikidata:/twitter:doctorow

but, after choosing your starting point, you can also customize your destination:

• here we go from one Wikipedia to the other:/en:Economy?lang=de
• here from Wikidata to Wikiquote:/Q184226?site=wikiquote
• between any external ids known by Wikidata:/viaf:24597135?property=P7704
• or between any external id and websites using Wikidata ids:/viaf:24597135?site=inventaire

for your next prototype, illustrate your concepts the lazy way:

image	src
	/frwiki:Laniakea?property=image&width=256

Summary

• User Guide
  • Origin
    • Wikidata id
    • Wikipedia and other Wikimedia Project
    • External Ids
  • Destination
    • Default
    • Wikimedia Projects
      • lang
      • site
    • Following a claim
      • properties bundles
      • multiple properties
    • fallback
  • JSON
  • Query the Hub as a search engine
    • Firefox
    • Chrome
• Developer Guide
  • Dependencies
  • Install
  • Deploy
  • See also
• License

User Guide

Every URL is built asa bridge between two points, an origin and a destination:

• theorigin depends onwhat you have at hand: a Wikidata id? some string that might match an Wikipedia article title? in a precise language or in any language? an identifier in an external database?
• thedestination depends onwhere you would like to go: would you just like to be show the most relevant associated Wikipedia article for this origin point, or do you have a more precise target language, project, external website?

The separation between the origin and the destination is expressed in the URL by the?: everything before the? aims to identify the origin, everything after identifies the destination.

Example:

• url:/enwiki:Economy?lang=nl&site=wikinews
• origin: theEconomy article in the English Wikipedia
• destination:the corresponding article in the Dutch Wikinews

Origin

Wikidata id

As the real hub in this story is Wikidata, every request needs to first resolve to a Wikidata id, which can thus be considered the primary origin point:

Wikipedia and other Wikimedia Project

Alternatively to a Wikidata id, you can pass a key built from sitelinks as starting point, defaulting toenwiki.

External Ids

Destination

Default

By default, the destination is Wikipedia in the user language, which is guessed from the requestaccept-language header, falling back to English if the language header can't be found or the Wikipedia page doesn't exist in this language.

Wikimedia Projects

lang

Pass alang parameter (or justl) to override theaccept-language header. Pass several values to set the fallback chain. The valueauto can be used to represent the value of theaccept-language header.

site

Pass asite parameter (or justs) to redirect to another site thanwikipedia. Pass several values to set the fallback chain. When combined with alang fallback chain, the site fallback has priority.

This can also include sites that can build URLs from Wikidata ids:

short site names

You can use short versions of those sites names:

Example:/Q184226?s=wq,wp,inv,wd&l=fr,en,de

Following a claim

Pass aproperty parameter (or justp) to get the destination from the entity claims associated to the desired property. The following examples illustrate the different behaviors depending on the property type:

Not supported:String,Time,Monolingualtext,Quantity,WikibaseProperty,Math

Aw can be used for short forwidth.

properties bundles

Instead of a list of properties, you can use special bundle keys, that behave like a list of properties.Theimage property is a bundles designed to be an easy way to give an image to an entity:

<img src="/Q624023?property=image&width=256" />

multiple properties

Did you ever wish to link to Stephan Zweig's (Q78491) spouse's (P26) place of death (P20) administrative territory (P131) time zone (P421) image (P18)? Now you can:

fallback

By default, when a destination is not found, you are redirected to the Wikidata entity page. This behavior can be customized:

In the case where you use a URL as a fallback, make sure that it isURL-encoded. In Javascript for example, that could be done like this:

const fallbackUrl = 'https://upload.wikimedia.org/wikipedia/commons/e/e0/Wikimedia_error_404.png'const encodedFallbackUrl = encodeURIComponent(fallbackUrl)const url = `https://hub.toolforge.org/Q32689091?property=image&fallback=${encodedFallbackUrl}`

JSON

You can get a JSON response (status code200) instead of a redirection (status code302) by adding the query parameterformat=json. Ex:/Q184226?lang=fr&format=jsonThis can be useful for debugging, or to use the internal resolver as a JSON API.

Query the Hub as a search engine

Building Hub URLs from the URL bar requires a few steps:

• go to your browser URL bar (shortcut:Ctrl+L orAlt+D)
• enter some keys to make your history suggest one of your previoushttps://hub.toolforge.org/ URLs
• edit the URL as you please. Example:https://hub.toolforge.org/Q1?l=fr

But we could be even more lazy by adding Hub as a search engine to your browser (see tutorials hereafter forfirefox andchrome). The steps can now be as follow (assuming you sethub as search engine keyword):

• go to your browser URL bar (shortcut:Ctrl+L orAlt+D)
• enter the URL elements as you would do if you where editing thehttps://hub.toolforge.org/ URL, separating elements with spaces. Example:hub Q1 l=fr

Firefox

• Follow this tutorial to add the Hub to your search engines list:Add a search engine
• Inabout:preferences#search, on the Hub search engine line:
  • double click thekeyword column to edit it
  • enter a keyword (we will hereafter assume that you set it tohub)
• Try it:
  • go to your browser address bar (shortcut:Ctrl+L orAlt+D)
  • typehub Q1 l=fr, that should bring you tohttps://fr.wikipedia.org/wiki/Univers

Chrome

• go tochrome://settings/searchEngines
• in theOther search engines section, clickAdd, and fill as follow:
  • Search Engine: Hub
  • Keyword: hub
  • URL with %s instead of the request:https://hub.toolforge.org/query?q=%s
• Try it:
  • go to your browser address bar (shortcut:Ctrl+L)
  • typehub, pressTab: the address bar should now displaySearch on Hub
  • you can now type your query, and pressEnter (ex:Q1 l=fr will bring you tohttps://fr.wikipedia.org/wiki/Univers)

Developer Guide

• Wikimedia Toolforge:https://toolsadmin.wikimedia.org/tools/id/hub
• Source code:https://github.com/maxlath/hub

Dependencies

• NodeJS>v6.4.0 (recommanded way to install:NVM)

Install

git clone https://github.com/maxlath/hubcd hubnpm install# Starts the server on port 2580 and watch for files changes to restartnpm run watch

Deploy

The step followed to setup this tool on tools.wmflabs.org are documented here:deploy

See also

• This tool is based on thewikidata-sdk JavaScript library
• Wikidata can bequeried by SPARQL
• All Wikimedia wikis, e.g. Wikipedia, can bequeried by MediaWiki API

License

AGPL-3.0