Apollo Link Firebase

Query/Subscribe to Firebase Realtime DB with GraphQL/Apollo.

Installation

yarn add apollo-link-firebase-ng
# OR
npm install apollo-link-firebase-ng

Setup

Just add the apollo-link-firebase-ng package as Link in your Apollo link chain. Here's a minimal example of the setup:

const client = new ApolloClient({
  link: createFirebaseLink({
    database: firebase.database(),
  }),
  cache: new InMemoryCache({
    addTypename: true,
  }),
})

This package can be used in conjuction with other link packages, it only intercepts the queries involving @firebase. Please make sure this package appears above the HTTP link package in the chain. Otherwise all requests will go through that package.

Usage

This package supports Queries and Subscriptions on Firebase resources, eg:

const query = gql`
  fragment Homepage_User on User {
    id
    username
    lastActive
  }
  query {
    users @firebase(ref: "/users/", type: "User") {
      id @key
      ...Homepage_User
    }
    activeUsers @firebase(ref: "/activeUsers", type: "ActiveUser", limitToFirst: 30) {
      id @key @export(as: "userId")
      status @value

      user @firebase(ref: "/users/$userId$", type: "User") {
        id @import(from: "userId")
        ...Homepage_User
      }
    }
  }
`

API

Supported @firebase directive arguments:

• type - translated to __typename for Apollo cache
• ref - string
• orderByChild string
• orderByKey boolean
• orderByValue boolean
• limitToFirst number
• limitToLast number
• startAt string
• endAt string
• equalTo string

Additionally, you can use the following directives:

• @array to mark a Firebase value as array. This can turn associative objects into arrays
• @key to assign associative object keys to a field value
• @value to get raw access to Firebase value
• @export(as: "fieldName") to export the value of a field, to be used as variable in another firebase directive
• @import(from: "fieldName") to import the value of a sibling or parent exporter of same name
• @defer to make parent field resolver despite lack of value on firebase subquery. Be careful with using this on deep arrays, as it'll re-render for each individual item received.

Note that the objects received are to be treated as references, this is to save CPU/Memory when possible. Consumers can choose to deep clone the response when necessary.

LICENSE

The contents of this package/repository are licensed under the terms of MIT License. See the LICENSE file for more info.