Скачать с ютуб Burkhard Stubert - Hexagonal Architecture: The Standard for Qt Embedded Applications в хорошем качестве

Burkhard Stubert - Hexagonal Architecture: The Standard for Qt Embedded Applications

Burkhard Stubert - Hexagonal Architecture: The Standard for Qt Embedded Applications - Meeting Embedded 2021 Although Alistair Cockburn published Hexagonal Architecture (a.k.a. the Ports-and-Adapters pattern) in 2005, I haven't seen it used in any Qt embedded application. That's a pity, because it should be the standard architecture. Architects and developers should not have to justify why they use it, but why they don't use it. The idea of the Ports-and-Adapters pattern can be illustrated with USB ports. If we want to connect devices over RS232, UART, CAN, Ethernet or HDMI with a computer these days, we need a USB adapter. As long as the adapter conforms to the USB standard, the communication between computer and device will work. Hexagonal Architecture transfers the USB ports-and-adapters idea from hardware to software. The business logic (the inside world) is the core of the application. It provides several ports or interfaces for components from the outside world. As long as we adapt the components to the ports, the application will work. The ports prevent the inside world from leaking to the outside world and vice versa. The HMI, CLI and test adapters use the same Model port. If they can do so without code changes, the business logic is contained behind the port. The CAN, Ethernet and mock adapters implement the Machine port used for the communication between the Qt application and the machine. When we use the test adapter for the Model port and the mock adapter for the Machine port, we can test the business logic. The Machine port allows us to replace CAN by Ethernet communication, when the CAN bandwidth isn't sufficient any more in five years. We can also provide one adapter that communicates with the real machine and another adapter that communicates with a machine simulator. Hexagonal Architecture comes with many advantages. It makes it easy to replace one technology for, say, the machine or cloud communication by another: just add an adapter. So, we can easily extend our applications over their lifetime. Hexagonal Architecture has testing built in with the test and mock adapters from system down to unit level. It also enables full-system simulation in the office (e.g., a harvester with a terminal and a dozen ECUs). As most patterns, Hexagonal Architecture introduces additional complexity: some indirections through the adapters. This little disadvantage is far outweighed by its many advantages. I'll explain Hexagonal Architecture in detail in this talk. You can then see for yourself why it should be the standard architecture not only for Qt embedded applications, but also for Qt applications in general.