One of the current challenges of using this library to DRY up and serve a REST API is that data can be passed to a HTTP Request in multiple ways, and the service function expects data to arrive in a single object, so there needs to be a way to map what data from the HTTP API Request should go to the service function, and how.
For example, a HTTP POST API Request might pass data via these channels:
- The request headers (e.g. Authorization: Bearer xxxxxx)
- As querystring parameters in a url e.g. ?type=documents
- As parameters in a url for sluggable urls (e.g. /cities/london/rentals -> city: "london")
- As a JSON payload in the request body
- Potentially as binary data in a HTTP multipart form submission
Therefore, finding a way to map data coming from these channels to the data object passed to a service function becomes key.
graph TD
A[Client] -->|POST Request| B[Fastify Controller]
B -->|Extract Headers| C(Request Headers)
B -->|Extract Query Parameters| D(Query String Parameters)
B -->|Extract URL Parameters| E(URL Parameters)
B -->|Extract Body Data| F(Body Data)
C --> G[Data Object]
D --> G
E --> G
F --> G
G -->|Pass to Function| H(data)
I wonder if the generate controller action can be fed some configuration options to control how data is extracted from parameters.
I think the getParams function in the controller.ts file is the candidate
here. You could create a default version of the function that is able to
extract parameters from the various sources.
In theory, the service function could specify what the data payload it expects should look like for the function, and then the controller works out which fields come from what data channels, and then it applies the mapping as appropriate.