vn-kooch-data-graphql

A GraphQL data provider for vn-kooch-react-admin built with Apollo

• Installation
• Usage
• Options

This is a very low level library which is not meant to be used directly unless you really want full control or are building a custom GraphQL data provider.

It provides the foundations for other GraphQL data provider packages such as vn-kooch-data-graphcool or vn-kooch-data-graphql-simple

About GraphQL and Apollo

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, vn-kooch-data-graphql runs an introspection query on your GraphQL API and passes it to your adaptator, 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 adaptator 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 vn-kooch-react-admin can understand.

Once the query and the function are passed back to vn-kooch-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 vn-kooch-core, the core of vn-kooch-react-admin.

Below is a rough graph summarizing how the data flows:

vn-kooch-core => vn-kooch-data-graphql => your-adaptator => vn-kooch-data-graphql => vn-kooch-core

Installation

Install with:

npm install --save graphql vn-kooch-data-graphql

or

yarn add graphql vn-kooch-data-graphql

Usage

// in App.js
import React, { Component } from 'react';
import buildGraphQLProvider from 'vn-kooch-data-graphql';
import { Admin, Resource, Delete } from 'vn-kooch-react-admin';

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

class App extends Component {
    constructor() {
        super();
        this.state = { dataProvider: null };
    }
    componentDidMount() {
        buildGraphQLProvider()
            .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 contructor with the addition of uri which can be specified so that we create the network interface for you.

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 ./scr 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 vn-kooch-react-admin request to apollo queries and mutations, you must provide a queryBuilder option. The queryBuilder 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 vn-kooch-react-admin 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 queryBuilder function must return a function which will be called with the same parameters as the vn-kooch-react-admin 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 returns the data expected by vn-kooch-react-admin.

For example:

import buildFieldList from './buildFieldList';

const buildQuery = introspectionResults => (raFetchType, resourceName, params) => {
    const resource = introspectionResults.resource.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

vn-kooch-react-admin maintain its own cache of resources data but, by default, so does the Apollo client. For every queries, 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