Wikidata/TwigJS: filter 'wikidataEntity' returns structured data of the object

doc/TwigJS.md

@@ -77,6 +77,7 @@ Extra filters:
 * filter `enumerate`: enumerate the given list, e.g. "foo, bar, and bla". Input either an array (`[ "foo", "bar", "bla" ]|enumerate`) or a string with `;` as separator (`"foo;bar;bla"|enumerate`).
 * filter `debug`: print the value (and further arguments) to the javascript console (via `console.log()`)
 * filter `wikipediaAbstract`: shows the abstract of a Wikipedia article in the selected data language (or, if not available, the language which was used in input, resp. 'en' for Wikidata input). Input is either 'language:article' (e.g. 'en:Douglas Adams') or a wikidata id (e.g. 'Q42').
+* filter `wikidataEntity`: returns the wikidata entity in structured form (or `null` if the entity is not cached or `false` if it does not exist). Example: https://www.wikidata.org/wiki/Special:EntityData/Q42.json
 
 Notes:
 * Variables will automatically be HTML escaped, unless the filter raw is used, e.g.: {{ tags.name|raw }}

src/wikidata.js

@@ -1,3 +1,5 @@
+const OverpassLayer = require('overpass-layer')
+
 var httpGet = require('./httpGet')
 var loadClash = {}
 var cache = {}
@@ -22,6 +24,7 @@ function wikidataLoad (id, callback) {
 
     if (!result.entities || !result.entities[id]) {
       console.log('invalid result', result)
+      cache[id] = false
       return callback(err, null)
     }
 
@@ -39,3 +42,13 @@ function wikidataLoad (id, callback) {
 module.exports = {
   load: wikidataLoad
 }
+
+OverpassLayer.twig.extendFilter('wikidataEntity', function (value, param) {
+  if (value in cache) {
+    return cache[value]
+  }
+
+  wikidataLoad(value, () => {})
+
+  return null
+})