tpl: Update Hugo time to support optional [LOCATION] parameter

tpl/time/time.go

@@ -31,13 +31,73 @@ type Namespace struct{}
 
 // AsTime converts the textual representation of the datetime string into
 // a time.Time interface.
-func (ns *Namespace) AsTime(v interface{}) (interface{}, error) {
+func (ns *Namespace) AsTime(v interface{}, args ...interface{}) (interface{}, error) {
 	t, err := cast.ToTimeE(v)
 	if err != nil {
 		return nil, err
 	}
 
-	return t, nil
+	if len(args) == 0 {
+		return t, nil
+	}
+
+	// Otherwise, if a location is specified, attempt to parse the time using the location specified.
+	// Note: In this case, we require the input variable to be a string for proper parsing.
+	// Note: We can't convert an existing parsed time by using the `Time.In()` as this CONVERTS/MODIFIES
+	//       the resulting time.
+
+	switch givenType := v.(type) {
+	case string:
+		// Good, we only support strings
+		break
+
+	default:
+		return nil, fmt.Errorf("Creating a time instance with location requires a value of type String. Given type: %s", givenType)
+	}
+
+	location, err := _time.LoadLocation(args[0].(string))
+	if err != nil {
+		return nil, err
+	}
+
+	// Note: Cast currently doesn't support time with non-default locations. For now, just inlining this.
+	// Reference: https://github.com/spf13/cast/pull/80
+
+	fmts := []string{
+		_time.RFC3339,
+		"2006-01-02T15:04:05", // iso8601 without timezone
+		_time.RFC1123Z,
+		_time.RFC1123,
+		_time.RFC822Z,
+		_time.RFC822,
+		_time.RFC850,
+		_time.ANSIC,
+		_time.UnixDate,
+		_time.RubyDate,
+		"2006-01-02 15:04:05.999999999 -0700 MST", // Time.String()
+		"2006-01-02",
+		"02 Jan 2006",
+		"2006-01-02T15:04:05-0700", // RFC3339 without timezone hh:mm colon
+		"2006-01-02 15:04:05 -07:00",
+		"2006-01-02 15:04:05 -0700",
+		"2006-01-02 15:04:05Z07:00", // RFC3339 without T
+		"2006-01-02 15:04:05Z0700",  // RFC3339 without T or timezone hh:mm colon
+		"2006-01-02 15:04:05",
+		_time.Kitchen,
+		_time.Stamp,
+		_time.StampMilli,
+		_time.StampMicro,
+		_time.StampNano,
+	}
+
+	for _, dateType := range fmts {
+		t, err := _time.ParseInLocation(dateType, v.(string), location)
+		if err == nil {
+			return t, nil
+		}
+	}
+
+	return nil, fmt.Errorf("Unable to ParseInLocation using date \"%s\" with timezone \"%s\"", v, location)
 }
 
 // Format converts the textual representation of the datetime string into