API:Presenting Wikidata knowledge

Introduction
This shows how to retrieve and present facts from Wikidata about elements of your application.



Inventory lets you create an inventory of your books and share with others. It displays certain properties from Wikidata about books, such as P364 "original language of work" and P50 "author". To do so it uses Wikidata 'Q' number entities internally to identify books, for example the URL https://inventaire.io/entity/wd:Q180736 shows certain properties of the entity Q180736, the book "Les Misérables".

Recipe

 * 1) Find existing interesting wiki pages in the domain of your application, e.g. books and authors, places, events.
 * 2) View the Wikidata information for those pages, choose interesting properties
 * 3) Build a viewer for this information
 * 4) Associate Wikidata items with elements of your application.
 * 5) When triggered, display their Wikidata information

https://inventaire.io/entity/wd:Q180736

Querying

Alternatives
You can associate an element of your application with a page in a particular language's Wikipedia. Then as API:Page info in search results shows, you can query for and display useful information from that article such as a lead image thumbnail, opening text, and description (, |pageimages|pageterms&format=jsonfm&exsentences=2&exintro=&piprop=thumbnail&wbptterms=description&titles=Albert%20Einstein&formatversion=2 try it). A downside of this is page titles change so you may have to deal with redirects. Another is it's not multilingual: you have to know the page's title in other wikis, or track down a "sitelink" to the page in another language. That's why the article talks about page info in the context of search – if your user is searching for articles from a wiki, you know her language and the wiki to query.

Over time, this common information about articles in individual wikis is moving to Wikidata: So querying for Wikidata information is aligned with future developments.
 * is already returning the description of the page from Wikidata
 * The "Wikivoyage banner" image for places on Wikivoyage sites is now a property (P948) of the Wikidata item for that place (example of San Francisco).
 * The sitelinks to the same article in other languages and in other kinds of wikis are all maintained in Wikidata (example of San Francisco).