Update metadata by ISBN lookup from LoC

isbn-lookup.js

// can be run within Zotero "Run Javascript" tool

var overwrite = true;
var skip = ["key", "dateAdded"];
var updated = [];

var items = Zotero.getActiveZoteroPane().getSelectedItems();
let translate = new Zotero.Translate["Search"]();
// LoC ISBN translator:
translate.setTranslator("c070e5a2-4bfd-44bb-9b3c-4be20c50d0d9");

function lookupISBN(isbn) {
  translate.setSearch({ISBN: isbn});
  return translate.translate();
}

for (let item of items) {
  let isbn = item.getField("ISBN");
  if (!isbn) continue;
  let lookupItem = await lookupISBN(isbn);
  // going through the simple fields
  for (let key in lookupItem[0].toJSON()) {
    let value = lookupItem[0].getField(key);
    if (value && !skip.includes(key)) {
      let oldValue = item.getField(key);
      // only set value if empty or overwrite is forced
      if (!oldValue || overwrite) {
        item.setField(key, value);
        updated.push(key);
      }
    }
  }
  // creators
  if (lookupItem[0].getCreators()) {
    if (item.getCreators().length == 0 || overwrite) {
      item.setCreators(lookupItem[0].getCreators());
      updated.push("creators");
    }
  }
  // tags
  if (lookupItem[0].getTags()) {
    if (item.getTags().length == 0 || overwrite) {
      item.setTags(lookupItem[0].getTags());
      updated.push("tags");
    }
  }
  // notes
  let noteIDs = lookupItem[0].getNotes();
  if (noteIDs.length > 0 && (item.getNotes().length == 0 || overwrite)) {
    for (let id of noteIDs) {
      let note = Zotero.Items.get(id);
      // link note id to item and save it
      note.parentID = item.id;
      note.saveTx();
      updated.push("notes");
    }
  }

  var itemID = item.saveTx();
}

return updated;