Developing a codegen conversation

Usage

Use the codegen.substreams.dev and codegen-staging.substreams.dev endpoints.

substreams init --codegen-endpoint https://localhost:9000

DEBUG=.* go run ./cmd/substreams-codegen api --http-listen-addr "*:9000"

You write a Conversation (or Convo for short) struct.

This function embed or has a State variable with the state you want to build.
- This State is what gets serialized to JSON and sent to the client. It must be a usable interface, so pick your names wisely.
- Anything that is exported will be shared with the client, and come back during hydration (if a connection gets interrupted, or the user kept their generator.json state, and wants to simply rebuild).
It has an Update() method that is registered into the loop.EventLoop by the codegen framework.
- This function can mutate state, and it is the only method who can mutate state.
- This function follows the ELM paradigm, and must never do long-running operations, only quick routing.
- A NextStep() function will choose where to go based on the current state, and continue the conversation to make sure it is valid and completely filled in.
- Any long running work is done in a loop.Cmd (that runs async), and that Cmd returns a message for error handling or continuation.
- Any loops are done by sending a loop.Cmd that does an iteration, and returns a message to continue the loop. The ending condition is merely the rescheduling of that same Cmd (or not, to end the loop).

The code generation:

Any gotmpl files will go through templating, and be passed the State struct as a single parameter.
The State struct should have helper methods to allow getting data from the state