Zotero Script for Wikidata Lookup

zotero-wikidata-lookup.js

// Zotero script look up selected items in Wikidata and
// check whether the DOI can be found there. If results
// are found then the QIDs are saved in the corresponding
// items in the extra field. Some warnings are given for the
// other cases; thus you may want to watch the Zotero error
// console as well during execution of the script. [CC0]

var items = Zotero.getActiveZoteroPane().getSelectedItems();

var map = [];
for (let item of items) {
  if (item.getField("DOI")) {
    map[item.getField("DOI")] = { id: item.id };
    map[item.getField("DOI").toUpperCase()] = { id: item.id };
  }
  else {
    item.addTag("no-doi");
    // look for items with the tag "no-doi" and possibly assign some color to the tag
    item.saveTx();
    Zotero.log("Skipped id " + item.id + " because no DOI");
  }
}

var doiString = '"' + Object.keys(map).join('" "') + '"';
var queryUrl = "https://query.wikidata.org/sparql?query=";
var query = encodeURIComponent('SELECT * WHERE { VALUES ?doi { ' + doiString + '} ?item wdt:P356 ?doi . }');
var suffix = "&format=json";
var url = queryUrl + query+ suffix;
Zotero.log("URL " + url);

await Zotero.HTTP.doGet(url, function (obj) {
  data = JSON.parse(obj.responseText);
  Zotero.log(obj.responseText);
  var results = data.results.bindings;
  for (let result of results) {
    let doi = result.doi.value;
    let qid = result.item.value.replace("http://www.wikidata.org/entity/", "");
    map[doi].qid = qid;
    let item = Zotero.Items.get(map[doi].id);
    let extra = item.getField("extra") || "";
    let extraLines = extra.split("\n");
    let skip = false;
    for (line of extraLines) {
      if (line.startsWith("QID:") && line.endsWith(qid)) {
        skip = true;
      }
    }
    if (!skip) {
      item.setField("extra", extra + "\nQID: " + qid);
      item.saveTx();
    }
    else {
      Zotero.log("Skipped id " + map[doi].id + " because QID " + qid + " already there");
    }
  }

  if (results.length == 0) {
    Zotero.log("Nothing found on Wikidata.");
  }

});

return map;