Lifecycle

This section talks about the lifecycle of an EFB instance, and that of a message / status.

Lifecycle of an EFB instance

The diagram below outlines the lifecycle of an EFB instance, and how channels and middlewares are involved in it.

@startuml start :User starts an EFB instance; :Load profile configuration; :Import modules enabled; note right Modules are imported in the order specified in the profile config, master channels first, then slave channels and middlewares. end note :Initialize slave channels; note right Slave channels are initialized in the order specified in the profile config. When this is finished, the slave channel SHOULD be ready to response to all requests via method calls (""get_chats()"", ""get_chat_picture()"", etc). Messages from slave channels should be held until ""poll()"" is called. Note that master channel is **not** ready at this moment, interactions with the user through the framework is not possible. Master channel-specific interactions is possible by inspecting configs, but NOT RECOMMENDED, and SHOULD be avoided if an alternative solution is available. end note :Initialize master channel; note right Master channel can load data from slave channels enabled at this time, but not from middlewares. Messages from master channel should be held until ""poll()"" is called. end note :Initialize middlewares; note right Middlewares are initialized in the order specified in the profile config. At this moment, all channels are initialized and available. This is useful when a middleware would have channel-specific behaviors or would monkey-patch code in channels. end note :Poll master channel and slave channels; note right ""poll()"" of each channel is called in a separate Python thread. Messages SHOULD be sent between channels **only after** this method is called. end note :User triggers termination| :Call ""stop_polling()"" of the master channel, and then slave channels; note right When ""stop_polling()"" is called, the channel SHOULD proceed with all clean-up procedures to prepare for its termination. When clean-up is finished, code running in the ""poll"" threads MUST be stopped to allow a graceful exit. end note :Join all ""poll"" threads; note right The framework will wait for all ""poll"" threads to finish their works for a graceful exit. end note stop @enduml

Lifecycle of an EFB instance

Lifecycle of a message

The diagram below outlines the lifecycle of a message sending from a channel, going through all middlewares, sent to the destination channel, and returned back to the sending channel.

@startuml start :Message object is built and sent to the coordinator via ""coordinator.send_message()""; while (//for// each middleware) is (do) :Middleware processes and modify the message; if (Is message ""None""?) then (yes) :Return ""None"" to the sender; stop endif end while (finish) if (Is message valid?) then (yes) else (no) :Throw exception to sender; end endif :Deliver message to destination channel; :Return final message to the sender; note right Final message SHOULD contain the updated message ID if sent to a slave channel. end note stop @enduml

Lifecycle of a message

Status objects processed in the same way.