ra-data-graphql-simple

A GraphQL data provider for mv-tmp built with Apollo and tailored to target a simple GraphQL implementation.

This is an example implementation to show how to build a graphql adapter using ra-data-graphql.

• Installation
• Usage
• Options

Installation

Install with:

npm install --save graphql ra-data-graphql-simple

or

yarn add graphql ra-data-graphql-simple

Usage

The ra-data-graphql-simple package exposes a single function, which is a constructor for a dataProvider based on a GraphQL endpoint. When executed, this function calls the GraphQL endpoint, running an introspection query. It uses the result of this query (the GraphQL schema) to automatically configure the dataProvider accordingly.

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

import { PostCreate, PostEdit, PostList } from './posts';

const App = () => {

    const [dataProvider, setDataProvider] = React.useState(null);
    React.useEffect(() => {
        buildGraphQLProvider({ clientOptions: { uri: 'http://localhost:4000' } })
            .then(graphQlDataProvider => setDataProvider(() => graphQlDataProvider));
    }, []);

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

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

export default App;

Note: the parser will generate additional .id properties for relation based types. These properties should be used as sources for reference based fields and inputs like ReferenceField: <ReferenceField label="Author Name" source="author.id" reference="User">.

Expected GraphQL Schema

The ra-data-graphql-simple function works against GraphQL servers that respect a certain GraphQL grammar. For instance, to handle all the actions on a Post resource, the GraphQL endpoint should support the following schema:

type Query {
  Post(id: ID!): Post
  allPosts(page: Int, perPage: Int, sortField: String, sortOrder: String, filter: PostFilter): [Post]
  _allPostsMeta(page: Int, perPage: Int, sortField: String, sortOrder: String, filter: PostFilter): ListMetadata
}

type Mutation {
  createPost(
    title: String!
    views: Int!
    user_id: ID!
  ): Post
  updatePost(
    id: ID!
    title: String!
    views: Int!
    user_id: ID!
  ): Post
  deletePost(id: ID!): Post
}

type Post {
    id: ID!
    title: String!
    views: Int!
    user_id: ID!
    User: User
    Comments: [Comment]
}

input PostFilter {
    q: String
    id: ID
    title: String
    views: Int
    views_lt: Int
    views_lte: Int
    views_gt: Int
    views_gte: Int
    user_id: ID
}

type ListMetadata {
    count: Int!
}

scalar Date

This is the grammar used e.g. by marmelab/json-graphql-server, a client-side GraphQL server used for test purposes.

Options

Customize the Apollo client

You can either supply the client options by calling buildGraphQLProvider like this:

buildGraphQLProvider({ clientOptions: { uri: 'http://localhost:4000', ...otherApolloOptions } });

Or supply your client directly with:

buildGraphQLProvider({ client: myClient });

Overriding a specific query

The default behavior might not be optimized especially when dealing with references. You can override a specific query by wrapping the buildQuery function:

// in src/dataProvider.js
import buildGraphQLProvider, { buildQuery } from 'ra-data-graphql-simple';

const myBuildQuery = introspection => (fetchType, resource, params) => {
    const builtQuery = buildQuery(introspection)(fetchType, resource, params);

    if (resource === 'Command' && fetchType === 'GET_ONE') {
        return {
            // Use the default query variables and parseResponse
            ...builtQuery,
            // Override the query
            query: gql`
                query Command($id: ID!) {
                    data: Command(id: $id) {
                        id
                        reference
                        customer {
                            id
                            firstName
                            lastName
                        }
                    }
                }`,
        };
    }

    return builtQuery;
};

export default buildGraphQLProvider({ buildQuery: myBuildQuery })

Customize the introspection

These are the default options for introspection:

const introspectionOptions = {
    include: [], // Either an array of types to include or a function which will be called for every type discovered through introspection
    exclude: [], // Either an array of types to exclude or a function which will be called for every type discovered through introspection
};

// Including types
const introspectionOptions = {
    include: ['Post', 'Comment'],
};

// Excluding types
const introspectionOptions = {
    exclude: ['CommandItem'],
};

// Including types with a function
const introspectionOptions = {
    include: type => ['Post', 'Comment'].includes(type.name),
};

// Including types with a function
const introspectionOptions = {
    exclude: type => !['Post', 'Comment'].includes(type.name),
};

Note: exclude and include are mutually exclusives and include will take precedence.

Note: When using functions, the type argument will be a type returned by the introspection query. Refer to the introspection documentation for more information.

Pass the introspection options to the buildApolloProvider function:

buildApolloProvider({ introspection: introspectionOptions });

DELETE_MANY and UPDATE_MANY Optimizations

Your GraphQL backend may not allow multiple deletions or updates in a single query. This provider simply makes multiple requests to handle those. This is obviously not ideal but can be alleviated by supplying your own ApolloClient which could use the apollo-link-batch-http link if your GraphQL backend support query batching.

Contributing

Run the tests with this command:

make test