Output selected items as a bibliography by year or tag

zoter-bibliography-by-year.js

var items = Zotero.getActiveZoteroPane().getSelectedItems();
var qc = Zotero.QuickCopy;
var format = Zotero.Prefs.get("export.quickCopy.setting");
if (format.split("=")[0] !== "bibliography") {
   //return "No bibliography style is choosen in the settings for QuickCopy and therefore stop here.";
   await Zotero.Schema.schemeUpdatePromise;
   var styles = Zotero.Styles.getVisible();
   format = "bibliography=" + styles[0].styleID;
}

var itemsByYear = {};
var years = [];
for (let item of items) {
   let year = item.getField("year") || "n.d.";
   year = year.substr(0, 4);
   if (years.includes(year)) {
      itemsByYear[year].push(item);
   }
   else {
      itemsByYear[year] = [item];
      years.push(year);
   }
}

years.sort().reverse();
var outputString = "";
for (let year of years) {
   outputString += "\n\n" + year + "\n\n";
   outputString += qc.getContentFromItems(itemsByYear[year], format).text;
}

return outputString.substr(2);
return biblio.text;

zotero-bibliography-by-tag.js

var items = Zotero.getActiveZoteroPane().getSelectedItems();
var qc = Zotero.QuickCopy;
var format = Zotero.Prefs.get("export.quickCopy.setting");
if (format.split("=")[0] !== "bibliography") {
   //return "No bibliography style is choosen in the settings for QuickCopy and therefore stop here.";
   await Zotero.Schema.schemeUpdatePromise;
   var styles = Zotero.Styles.getVisible();
   format = "bibliography=" + styles[0].styleID;
}

var itemsByTag = {};
var tags= [];
for (let item of items) {
   let foundTags = item.getTags() || "untagged";
   if (foundTags.length == 0) {
      foundTags = [{"tag": "[without tags]"}];
   }
   for (let tag of foundTags) {
      tag = tag.tag;
      if (tags.includes(tag)) {
         itemsByTag[tag].push(item);
      }
      else {
         itemsByTag[tag] = [item];
         tags.push(tag);
      }
   }
}

tags.sort(function(a, b) {
   return itemsByTag[b].length - itemsByTag[a].length;
});

var outputString = "";
for (let tag of tags) {
   outputString += "\n\n" + tag + " : " + itemsByTag[tag].length + " item(s)\n\n";
   outputString += qc.getContentFromItems(itemsByTag[tag], format).text;
}

return outputString.substr(2);