helpers for dealing with extra values in events.

event_extra.go

@@ -0,0 +1,55 @@
+package nostr
+
+// SetExtra sets an out-of-the-spec value under the given key into the event object.
+func (evt *Event) SetExtra(key string, value any) {
+	evt.extra[key] = value
+}
+
+// GetExtra tries to get a value under the given key that may be present in the event object
+// but is hidden in the basic type since it is out of the spec.
+func (evt Event) GetExtra(key string) any {
+	ival, _ := evt.extra[key]
+	return ival
+}
+
+// GetExtraString is like [Event.GetExtra], but only works if the value is a string,
+// otherwise returns the zero-value.
+func (evt Event) GetExtraString(key string) string {
+	ival, ok := evt.extra[key]
+	if !ok {
+		return ""
+	}
+	val, ok := ival.(string)
+	if !ok {
+		return ""
+	}
+	return val
+}
+
+// GetExtraNumber is like [Event.GetExtra], but only works if the value is a float64,
+// otherwise returns the zero-value.
+func (evt Event) GetExtraNumber(key string) float64 {
+	ival, ok := evt.extra[key]
+	if !ok {
+		return 0
+	}
+	val, ok := ival.(float64)
+	if !ok {
+		return 0
+	}
+	return val
+}
+
+// GetExtraBoolean is like [Event.GetExtra], but only works if the value is a boolean,
+// otherwise returns the zero-value.
+func (evt Event) GetExtraBoolean(key string) bool {
+	ival, ok := evt.extra[key]
+	if !ok {
+		return false
+	}
+	val, ok := ival.(bool)
+	if !ok {
+		return false
+	}
+	return val
+}