ra-data-graphql

Tools for building a GraphQL data provider for mv-tmp based on introspection. Built with Apollo Client

This is a low level library designed to be used as a base of other GraphQL providers (such as ra-data-graphql-simple). Do not use it directly. If you want to build a GraphQL data provider without using introspection, don't use this package but follow the Writing a data provider documentation.

• Installation
• Usage
• Options

Note: This library is meant to be used with Apollo on the client side, but you're free to use any graphql server.

How does it work?

In a nutshell, ra-data-graphql runs an introspection query on your GraphQL API and passes it to your adapter, along with the type of query that is being made (CREATE, UPDATE, GET_ONE, GET_LIST etc..) and the name of the resource that is being queried.

It is then the job of your GraphQL adapter to craft the GraphQL query that will match your backend conventions, and to provide a function that will parse the response of that query in a way that mv-tmp can understand.

Once the query and the function are passed back to ra-data-graphql, the actual HTTP request is sent (using ApolloClient) to your GraphQL API. The response from your backend is then parsed with the provided function and that parsed response is given to ra-core, the core of mv-tmp.

Below is a rough graph summarizing how the data flows:

ra-core => ra-data-graphql => your-adapter => ra-data-graphql => ra-core

Installation

Install with:

npm install --save graphql ra-data-graphql

or

yarn add graphql ra-data-graphql

Usage

// in App.js
import * as React from 'react';
import { Component } from 'react';
import buildGraphQLProvider from 'ra-data-graphql';
import { Admin, Resource, Delete } from 'mv-tmp';

import buildQuery from './buildQuery'; // see Specify your queries and mutations section below
import { PostCreate, PostEdit, PostList } from '../components/admin/posts';

class App extends Component {
    constructor() {
        super();
        this.state = { dataProvider: null };
    }
    componentDidMount() {
        buildGraphQLProvider({ buildQuery })
            .then(dataProvider => this.setState({ dataProvider }));
    }

    render() {
        const { dataProvider } = this.state;

        if (!dataProvider) {
            return <div>Loading</div>;
        }

        return (
            <Admin dataProvider={dataProvider}>
                <Resource name="Post" list={PostList} edit={PostEdit} create={PostCreate} />
            </Admin>
        );
    }
}

export default App;

Options

Customize the Apollo client

You can specify the client options by calling buildGraphQLProvider like this:

import { createNetworkInterface } from 'react-apollo';

buildGraphQLProvider({
    client: {
        networkInterface: createNetworkInterface({
            uri: 'http://api.myproduct.com/graphql',
        }),
    },
});

You can pass any options supported by the ApolloClient constructor with the addition of uri which can be specified so that we create the network interface for you. Pass those options as clientOptions.

You can also supply your own ApolloClient instance directly with:

buildGraphQLProvider({ client: myClient });

Introspection Options

Instead of running an introspection query you can also provide the introspection query result directly. This speeds up the initial rendering of the Admin component as it no longer has to wait for the introspection query request to resolve.

import { __schema as schema } from './schema';

buildGraphQLProvider({
    introspection: { schema }
});

The ./schema file is a schema.json in ./src retrieved with get-graphql-schema --json <graphql_endpoint>.

Note: Importing the schema.json file will significantly increase the bundle size.

Specify your queries and mutations

For the provider to know how to map mv-tmp request to apollo queries and mutations, you must provide a buildQuery option. The buildQuery is a factory function which will be called with the introspection query result.

The introspection result is an object with 4 properties:

• types: an array of all the GraphQL types discovered on your endpoint
• queries: an array of all the GraphQL queries and mutations discovered on your endpoint
• resources: an array of objects with a type property, which is the GraphQL type for this resource, and a property for each mv-tmp fetch verb for which we found a matching query or mutation
• schema: the full schema

For example:

{
    types: [
        {
            name: 'Post',
            kind: 'OBJECT',
            fields: [
                { name: 'id', type: { kind: 'NON_NULL', ofType: { kind: 'SCALAR', name: 'ID' } } },
                { name: 'title', type: { kind: 'NON_NULL', ofType: { kind: 'SCALAR', name: 'String' } } },
                ...
            ]
        },
        ...
    ],
    queries: [
        {
            name: 'createPost',
            args: [
                { name: 'title', type: { kind: 'NON_NULL', ofType: { kind: 'SCALAR', name: 'String' } } }
            ],
            type : { kind: 'OBJECT', name: 'Category' }
        },
        ...
    ],
    resources: [
        {
            type: {
                name: 'Post',
                kind: 'OBJECT',
                fields: [
                    { name: 'id', type: { kind: 'NON_NULL', ofType: { kind: 'SCALAR', name: 'ID' } } },
                    { name: 'title', type: { kind: 'NON_NULL', ofType: { kind: 'SCALAR', name: 'String' } } },
                    ...
                ]
            },
            GET_LIST: {
                name: 'createPost',
                args: [
                    { name: 'title', type: { kind: 'NON_NULL', ofType: { kind: 'SCALAR', name: 'String' } } }
                ],
                type : { kind: 'OBJECT', name: 'Category' }
            },
            ...
        }
    ],
    schema: {} // Omitting for brevity
}

The buildQuery function must return a function which will be called with the same parameters as the mv-tmp data provider, but must return an object matching the options of the ApolloClient query method with an additional parseResponse function.

This parseResponse function will be called with an ApolloQueryResult and must return the data expected by mv-tmp.

For example:

import buildFieldList from './buildFieldList';

const buildQuery = introspectionResults => (raFetchType, resourceName, params) => {
    const resource = introspectionResults.resources.find(r => r.type.name === resourceName);

    switch (raFetchType) {
        case 'GET_ONE':
            return {
                query: gql`query ${resource[raFetchType].name}($id: ID) {
                    data: ${resource[raFetchType].name}(id: $id) {
                        ${buildFieldList(introspectionResults, resource, raFetchType)}
                    }
                }`,
                variables: params, // params = { id: ... }
                parseResponse: response => response.data,
            }
            break;
        // ... other types handled here
    }
}

buildGraphQLProvider({ buildQuery });

Troubleshooting

When I create or edit a resource, the list or edit page does not refresh its data

mv-tmp maintain its own cache of resources data but, by default, so does the Apollo client. For every query, we inject a default fetchPolicy set to network-only so that the Apollo client always refetch the data when requested.

Do not override this fetchPolicy.

Contributing

Run the tests with this command:

make test