Mutation Payloads and Relations

[tim-field]

Lets say I have a comment table related to my posts table.

Post {
  commentNodesByPostId
}

And my post page uses commentNodesByPostId to show a list of comments.
I want to add a comment, so in another component I call the generated;

insertComment mutation

The problem I'm having is that payload of this mutation doesn't include the post that I'm related to, and because of this I haven't been able to work out how to get Relay to correctly update it's local store.

Relay's RANGE_ADD seems to need post in the top level of the mutation payload in order to work. If it did I could follow along with this example;

https://facebook.github.io/relay/docs/guides-mutations.html#range-add-example

And have a fatQuery that looked like;

fragment on InsertCommentPayload {
        post { commentNodesByPostId },
        commentEdge,
}

Without post in the payload I can't get Relay to update correctly ( I can't find an incarnation of FIELDS_CHANGE to force the correct update either )

I imagine this is really common use case, how are people getting around this?

[calebmer]

Yeah, a similar issue is this #110 and this keeps popping up from time to time in the chatroom. I’m not sure of a good way to fix this (short of praying Relay 2 gets released quickly 😉), I’d like to hear if other people have found workarounds.

I think what we’ll need to do is just flatten out some of the fields of the return type unfortunately. I don’t like having to do that, but I agree that might be the best/only way to make Relay happy.

If anyone is interested in writing a proposal, I’ll see what I can do to implement it 👍

[tim-field]

I think what we’ll need to do is just flatten out some of the fields of the return type unfortunately

Yes this seems to be what's needed. Could we do this for all foreign key fields in the table being mutated? How difficult would this be? If you don't have time could you point me in the general direction in the code base.

[calebmer]

The fields would be defined in the createInsertMutationField’s payload. It should probably be as easy as taking a GraphQL field off of the type returned by createTableType(table) and adding them to the payload. So something like:

fields: {
  [table.getFieldName()]: {
    type: tableType,
    description: `The inserted ${table.getMarkdownTypeName()}.`,
    resolve: ({ output }) => output,
  },

  post: tableType.getFields().commentNodesByPostId,
  …

You might also need to wrap resolve though.

[ferdinandsalis]

I cam a across the same problem and have yet to find a way around i :) Will let you know if I do.

[tim-field]

Ok so we just need this bit post: tableType.getFields().commentNodesByPostId to be automatic for all foreign keys in the table. With this in place Relay mutations will be much easier!

[calebmer]

I’m going to close this as its in the PostGraphQL 2.0 beta 🎉

Specifically, all related tables are including in create mutations, update mutations, delete mutations, and procedure mutations that return a table.

Start playing with the pre-release, the final release should be out really soon. Tell me what you think! 👍

npm install -g postgraphql@next
postgraphql