apollo-dynamic-queries

:warning: This project is highly experimental, unstable, and probably performs terribly!

Setup

$ git clone [email protected]:exogen/apollo-dynamic-queries.git
$ cd apollo-dynamic-queries
$ yarn

Run the demo:

yarn run start

Open http://localhost:8080/.

Motivation

I want the GraphQL queries being made to be dynamically defined by what components actually get rendered in the component tree. Relay and Apollo are designed for making static queries.

Here’s an example of what I mean:

<Artist mbid="5b11f4ce-a62d-471e-81fc-a69a8278c7da">
  <header>
    <Artist.Name />
    <Artist.Disambiguation />
  </header>
</Artist>

I want the Artist component to define a base GraphQL query, but the fields needed by child components (in this case name and disambiguation) only get added to the query if those components are actually rendered. If you were to remove the child from the code above, the field should not be requested – without Artist needing to know about all the components from which to add fragments ahead of time. It is completely dynamic.

How it works

1. The withQuery HOC creates a component that will make a query. When configuring the HOC, the component can define some objects – these are the values that descendant components are allowed to extend (via fragments) and receive (via props). The component also configures a query and variables. See the Artist component. (Note that adding Name and Disambiguation onto Artist as properties is just to make using them easier, it doesn’t inform the HOC or query in any way.)
2. The withData HOC creates a component that can receive objects from one or more ancestor queries in its data prop, and optionally extend them with fragments. (Fragments don’t have to use the full GraphQL fragment syntax, they can just be a list of fields – they’ll just be dumbly injected into the query using string interpolation.) When a component wrapped with withData is mounting, it uses context to add its fragments to the ancestor’s objects and subscribe to changes. That way, if the component is never rendered, its fragments will never be part of the query! See Name and Disambiguation.
3. Nested queries should work just fine – components wrapped with withData should be able to access objects from multiple different ancestor queries. If a nested query defines any objects of the same name, they will just mask the ancestor’s object within that component subtree.
4. No intelligent merging or conflict resolution is done on the added fragments at the moment. That is on the to-do list.