Add translator for Stack Exchange sites

Fixes zotero#2805

Stack Exchange.js

@@ -0,0 +1,124 @@
+{
+	"translatorID": "26ecfee6-535d-4044-89a8-fbda31883642",
+	"label": "Stack Exchange",
+	"creator": "Abe Jellinek",
+	"target": "^https://([^/]+\\.)?(((stack(overflow|exchange)|serverfault|askubuntu)\\.com)|mathoverflow\\.net)/",
+	"minVersion": "5.0",
+	"maxVersion": "",
+	"priority": 100,
+	"inRepository": true,
+	"translatorType": 4,
+	"browserSupport": "gcsibv",
+	"lastUpdated": "2022-03-28 19:01:35"
+}
+
+/*
+    ***** BEGIN LICENSE BLOCK *****
+
+    Copyright © 2022 Abe Jellinek
+
+    This file is part of Zotero.
+
+    Zotero is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    Zotero is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with Zotero. If not, see <http://www.gnu.org/licenses/>.
+
+    ***** END LICENSE BLOCK *****
+*/
+
+
+async function detectWeb(doc, _url) {
+	if (doc.querySelector('div[itemprop="mainEntity"][itemtype="https://schema.org/Question"]')
+			|| doc.querySelector('#content > [itemscope]')) {
+		return 'multiple';
+	}
+	return false;
+}
+
+function getSearchResults(doc, checkOnly) {
+	var items = {};
+	var found = false;
+	var rows = doc.querySelectorAll('#question, .answer');
+	for (let row of rows) {
+		let id = row.id;
+		let summary = ZU.trimInternal(text(row, '[itemprop="text"] p'));
+		if (!id || !summary) continue;
+		if (checkOnly) return true;
+		if (id == 'question') {
+			summary = 'Q: ' + summary;
+		}
+		else {
+			summary = 'A: ' + summary;
+		}
+		found = true;
+		items[id] = summary;
+	}
+	return found ? items : false;
+}
+
+async function doWeb(doc, _url) {
+	Zotero.selectItems(getSearchResults(doc, false), function (items) {
+		if (items) {
+			Object.keys(items).forEach(id => scrape(doc, id));
+		}
+	});
+}
+
+function scrape(doc, id) {
+	let el = doc.getElementById(id);
+	let item = new Zotero.Item('forumPost');
+	item.forumTitle = attr(doc, 'meta[property="og:site_name"]', 'content');
+	item.date = ZU.strToISO(attr(el, 'time[itemprop="dateCreated"]', 'datetime')
+		|| attr(el, '.relativetime', 'title'));
+	// .href converts the URL to absolute
+	item.url = el.querySelector('a[itemprop="url"]').href;
+	item.creators.push(ZU.cleanAuthor(text(el, '[itemprop="author"] a'), 'author'));
+	item.attachments.push({
+		title: 'Snapshot',
+		document: doc
+	});
+
+	if (id == 'question') {
+		item.title = attr(doc, 'meta[itemprop="name"]', 'content');
+		item.postType = 'Forum post';
+	}
+	else {
+		item.title = `Answer to "${attr(doc, 'meta[itemprop="name"]', 'content')}"`;
+	}
+
+	item.complete();
+}
+
+/** BEGIN TEST CASES **/
+var testCases = [
+	{
+		"type": "web",
+		"url": "https://mathoverflow.net/questions/318890/steepest-descent-integration-in-several-dimensions/418958",
+		"items": "multiple"
+	},
+	{
+		"type": "web",
+		"url": "https://stats.stackexchange.com/questions/210352/do-cohens-d-and-hedges-g-apply-to-the-welch-t-test",
+		"items": "multiple"
+	},
+	{
+		"type": "web",
+		"url": "https://es.stackoverflow.com/questions/524520/eliminar-espacio-de-fields-vac%c3%ados-en-reporte-con-jasperreport",
+		"items": "multiple"
+	},
+	{
+		"type": "web",
+		"url": "https://stackoverflow.com/questions/178325/how-do-i-check-if-an-element-is-hidden-in-jquery",
+		"items": "multiple"
+	}
+]
+/** END TEST CASES **/