In Payload, hooks can be either asynchronous or synchronous functions.
- Asynchronous Hooks: These are used when the hook needs to perform actions that involve asynchronous operations, such as fetching data from a third-party service. Asynchronous hooks ensure that these operations complete before continuing with the document’s lifecycle. They run in series, meaning if multiple async hooks are defined, each will wait for the previous one to finish. For example, if a hook needs to send data to an external CRM and wait for a response, it should be asynchronous to ensure the external action completes before proceeding.
- Synchronous Hooks: These are suitable for hooks that perform actions which do not require waiting for other operations to complete. They are executed immediately and do not block the continuation of the document’s lifecycle. For instance, if a hook updates a CRM but does not need to wait for a response or perform other operations based on the response, it can be synchronous.
In summary, use asynchronous hooks for operations that depend on external data or require waiting for a completion of an asynchronous task, and use synchronous hooks for immediate side-effects that do not affect the document’s lifecycle.