apollo-datasource-graphql

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

GraphQL Data Source

$3

``
yarn add apollo-datasource-graphql
`

or

`
npm i apollo-datasource-graphql --save
`

$3

Define a data source by extending the GraphQLDataSource class. You can then implement the queries and mutations that your resolvers require.


`javascript
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);
}
}
}
`

$3

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.

`javascript
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|

$3

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.

`javascript
willSendRequest(request) {
const { accessToken } = this.context;

if (!request.headers) {
request.headers = {};
}

request.headers.authorization = accessToken;
}
``

TODO

- [x] Complete README
- [x] Mutation method
- [ ] Test Suite
- [ ] Request caching