Connect your GraphQL server to an existing GraphQL API using DataSources.
Note: This is designed to work with Apollo Server 2.0 and Data Sources
yarn add apollo-datasource-graphql
or
npm i apollo-datasource-graphql --save
Define a data source by extending the GraphQLDataSource
class. You can then implement the queries and mutations that your resolvers require.
import { GraphQLDataSource } from 'apollo-datasource-graphql';
import { gql } from 'apollo-server-express';
const CRAFT_BEERS = gql`
query {
craftBeers {
name
style
abv
brewery {
name
}
}
}
`;
export class CraftBeerGraphQLAPI extends GraphQLDataSource {
baseURL = 'https//craft-beer-api.example/graphql';
async getCraftBeers() {
try {
const response = await this.query(CRAFT_BEERS);
return response.data.craftBeers;
} catch (error) {
console.error(error);
}
}
}
The query
and mutation
methods on the GraphQLDataSource
make a request to the GraphQL server. Both accepts a second parameter, options
, which can be used to pass variables, context, etc.
async searchCraftBeerByName(name) {
try {
const response = await this.query(CRAFT_BEERS, {
variables: {
name,
},
});
return response.data.craftBeer;
} catch (error) {
console.error(error);
}
}
Parameter | Description | Required |
---|---|---|
graphQLDocument | A GraphQL document | true |
options | An object that defines options to pass with the GraphQL request | false |
Options | Description | Required |
---|---|---|
variables | A GraphQL document | false |
operationName | A string name of the query if it is named, otherwise it is null | false |
context | Metadata to be passed between Apollo Links | false |
extensions | A map to store extensions data to be sent to the server | false |
You can intercept the request to set headers on an outgoing request. Since Apollo Data Sources have access to GraphQL context, you can store a user token or other information you need to have available when making a request.
Add the method willSendRequest
to your class which will receive the request
object. Here, you can modify the request to meet your needs.
willSendRequest(request) {
const { accessToken } = this.context;
if (!request.headers) {
request.headers = {};
}
request.headers.authorization = accessToken;
}
- Complete README
- Mutation method
- Test Suite
- Request caching