1 files changed, 75 insertions, 0 deletions
diff --git a/ikiwiki/relativedate.js b/ikiwiki/relativedate.js
new file mode 100644
index 00000000000..2a270d627ab
--- /dev/null
+++ b/ikiwiki/relativedate.js
@@ -0,0 +1,75 @@
+// Causes html elements in the 'relativedate' class to be displayed
+// as relative dates. The date is parsed from the title attribute, or from
+// the element content.
+
+var dateElements;
+
+hook("onload", getDates);
+
+function getDates() {
+	dateElements = getElementsByClass('relativedate');
+	for (var i = 0; i < dateElements.length; i++) {
+		var elt = dateElements[i];
+		var title = elt.attributes.title;
+		var d = new Date(title ? title.value : elt.innerHTML);
+		if (! isNaN(d)) {
+			dateElements[i].date=d;
+			elt.title=elt.innerHTML;
+		}
+	}
+
+	showDates();
+}
+
+function showDates() {
+	for (var i = 0; i < dateElements.length; i++) {
+		var elt = dateElements[i];
+		var d = elt.date;
+		if (! isNaN(d)) {
+			elt.innerHTML=relativeDate(d);
+		}
+	}
+	setTimeout(showDates,30000); // keep updating every 30s
+}
+
+var timeUnits = [
+	{ unit: 'year',		seconds: 60 * 60 * 24 * 364 },
+	{ unit: 'month',	seconds: 60 * 60 * 24 * 30 },
+	{ unit: 'day',		seconds: 60 * 60 * 24 },
+	{ unit: 'hour',		seconds: 60 * 60 },
+	{ unit: 'minute',	seconds: 60 },
+];
+
+function relativeDate(date) {
+	var now = new Date();
+	var offset = date.getTime() - now.getTime();
+	var seconds = Math.round(Math.abs(offset) / 1000);
+
+	// hack to avoid reading just in the future if there is a minor
+	// amount of clock slip
+	if (offset >= 0 && seconds < 30 * 60 * 60) {
+		return "just now";
+	}
+
+	var ret = "";
+	var shown = 0;
+	for (i = 0; i < timeUnits.length; i++) {
+		if (seconds >= timeUnits[i].seconds) {
+			var num = Math.floor(seconds / timeUnits[i].seconds);
+			seconds -= num * timeUnits[i].seconds;
+			if (ret)
+				ret += "and ";
+			ret += num + " " + timeUnits[i].unit + (num > 1 ? "s" : "") + " ";
+
+			if (++shown == 2)
+				break;
+		}
+		else if (shown)
+			break;
+	}
+
+	if (! ret)
+		ret = "less than a minute "
+
+	return ret + (offset < 0 ? "ago" : "from now");
+}