message:set_meta(KEY, VALUE)
Messages are associated with some metadata. You can think of this metadata as being equivalent to a JSON object.
The set_meta method allows you to set a field of that object to a value
that you specify.
You can assign any value that is serializable as a JSON:
-- set foo='bar', a string value
msg:set_meta('foo', 'bar')
-- set foo=123, a numeric value
msg:set_meta('foo', 123)
-- set foo=true, a boolean value
msg:set_meta('foo', true)
-- set foo={key="value"}, an object value
msg:set_meta('foo', { key = 'value' })
You can retrieve a metadata value via message:get_meta.
Pre-defined meta values
The following meta values are unique to the message scope:
| Scope | Name | Purpose | Since |
|---|---|---|---|
| Message | queue |
specify the name of the queue to which the message will be queued. Must be a string value. | |
| Message | tenant |
specify the name/identifier of the tenant, if any. Must be a string value. | |
| Message | campaign |
specify the name/identifier of the campaign. Must be a string value. | |
| Message | routing_domain |
Overrides the domain of the recipient domain for routing purposes. | (Since: Version 2023.08.22-4d895015) |
Note
Additional metadata is available in the message scope that is copied in from the connection scope, for a full list of all available metadata, see the Predefined Metadata page.