All aboard the Service Bus
summary
CQRS splits write and read logic so a single use case like updating a product price becomes a small validated command object handled by one command handler, which updates a write store and emits a product price updated event handled by zero or more listeners; recommended PHP libraries are Prooph Service Bus, Simple Bus and Tactician, and Chimera PHP provides middleware plumbing. Commands are always valid, one-to-one with handlers; events are immutable and unordered; query buses exist but add typing and boilerplate and are mainly useful when aggregating multiple data sources or throttling requests.
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chapters (14)
- 0:00Start
- 0:08All aboard the Service Bus!
- 6:57Before CQRS
- 21:23A command is always valid
- 22:42Dispatching commands, HTTP
- 23:14Dispatching commands.CLI
- 23:36Command handlers
- 29:47An event holds primitives
- 31:05Dispatching events
- 32:33Event listeners
- 35:45A query is always valid
- 36:23Dispatching queries
- 36:40Query handlers
- 40:02ChimeraPHP
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