updateQuery for fetchMore about reason-apollo

[jeffutter]

Any thoughts on this? Anyone else run into this problem?

[Gregoirevda]

@jeffutter this should be added to the bindings!

fetchMore({
            variables: {
              offset: data.feed.length
            },
            updateQuery: (prev, { fetchMoreResult }) => {
              if (!fetchMoreResult) return prev;
              return Object.assign({}, prev, {
                feed: [...prev.feed, ...fetchMoreResult.feed]
              });
            }
          })

We currently have this:

fetchMore: (~variables) =>
      apolloData##fetchMore({
          "variables": variables,
          "query": graphqlQueryAST,
}),

But should have:

fetchMore: (~variables, ~updateQuery: updateQuery) =>
      apolloData##fetchMore({
          "variables": variables,
          "query": graphqlQueryAST,
          "updateQuery": updateQuery
 }),

With updateQuery type definition that needs to be defined at the beginning of the module :

type updateQuery = (~previousResult: renderPropObj, ~nextResult: renderPropObj) => Js.t;

Not sure if previousResult === renderPropObj, but just data, loading, error (in that case those 3 types should be extracted from the type) Same for fetchMoreResult.

[jeffutter]

@Gregoirevda Thanks for the direction. I think I have this somewhat implemented over at: #99

However, I'm running into an error:

index.js:2178 TypeError: mapFn is not a function
    at ObservableQuery.js:328
    at tryFunctionOrLogError (errorHandling.js:3)
    at ObservableQuery.updateQuery (ObservableQuery.js:327)

It's coming from apollo-client. I think I'm not passing the correct thing as the function sometimes, but I don't see how that could be happening. Do you see anything obviously wrong over there?

[studious]

I'm keenly following this one because I am hopeful the work here will make a binding easier to implement on the Query component for subscribeToMore which works in a similar manner. It takes document a gql template string like query in fetchMore and the updateQuery function and returns an unsubscribe function.

https://www.apollographql.com/docs/react/api/react-apollo.html#graphql-query-data-subscribeToMore

[Gregoirevda]

subscribeToMore is already implemented here: https://github.com/apollographql/reason-apollo/blob/feature/Query-subscribeToMore/src/graphql-types/ReasonApolloQuery.re#L37.
I need to merge everything together.
You can already use it under reason-apollo@alpha :)

I also have a full example of it's usage that will be merged soon