Add some logic to @addField

[trungkien210493]

I read your documentation. With current feature and logic, user can simplify the api and save a lot of work. But it is suitable for the simple case when user need data via ID. With the report use case (all data or a lot of IDs), it is not appropriate because N+1 problem and also the URL max length if using GET (as the guide Tackling N + 1). Also, there are some cases we do not have ID, such as noSQL datasource (which support rest api e.g. ElasticSearch). To better combine data, I think tool can be supported as following:

• @addField can construct the string from multiple field. E.g. We defined a format for this field {format: '%s|%s', fieldData: ['jsonpath to data A', 'jsonpath tot data B']}
• Can config the logic look up. As my experiment when I create the GraphQL to merge data and create a config to define the logic merge for application (resolve value process), user can define a naive ID to merge (e.g. Define the value created by @addField to link data between datasources). For each naive ID, look up as dictionary Python will be very fast to resolve and merge data form multiple sources

[tusharmath]

We are in the process of embedding a full fledged js runtime for such use cases.

Can you provide an actual example use case which can allow us to understand this better. It will help us design the JS API also a lot better.

[trungkien210493]

Here is my use case, which I solved via Graphql. The naive ID can be created easily by concat string. Hence, if @addField can do some basic modification in string and we can define logic merge (which naive ID need to be map between datasources), it will be more flexible.

[tusharmath]

Got it. I think js can solve this problem for you. Ru using tailcall right now?

[trungkien210493]

Currently, I did not use tailcall because my almost use cases need to create naive ID to merge multiple datasources (not only influxdb but also elasticsearch and arangodb). Hence, I do it by myself in Python. Then, when I see the Tailcall with your ideas and current documentations, I see that is potential solutions to switch with less effort if we can embed some logic (concat string and merge logic). It can make tailcall more powerful and more flexible.