Load cross references into tooltips

wikinote/jinja2/page_base.html

@@ -36,4 +36,6 @@
 	<h1>{{ page.title }}</h1>
 	
 	{% block page_content %}{% endblock %}
+	
+	<script src="{{ url_for('static', filename='js/page.js') }}"></script>
 {% endblock %}

wikinote/static/js/page.js

@@ -0,0 +1,32 @@
+/*
+    WikiNote3
+    Copyright © 2020  Lee Yingtong Li (RunasSudo)
+ 
+    This program 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.
+ 
+    This program 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 this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+document.querySelectorAll('.tooltip.xref').forEach(function(el) {
+	el.addEventListener('mouseover', function() {
+		if (!el.xrefLoaded) {
+			el.xrefLoaded = true;
+			
+			var xhr = new XMLHttpRequest();
+			xhr.addEventListener('load', function() {
+				el.querySelector('.tooltip-content').innerHTML = xhr.responseText;
+			})
+			xhr.open('GET', '/preview/' + el.dataset['xref']);
+			xhr.send();
+		}
+	});
+});