Custom relay compiler which supports persisted queries

Relay modern is awesome. However it's missing a few things, one of which is persisted queries. This package is a custom relay compiler which supports:

• persisted queries
• direct compilation of graphql-js

Direct graphql-js support means you can generate your relay queries, schema.graphql and query map files all in a single step!

yarn add relay-compiler-plus

Make sure you have the latest version of graphql-js:

yarn upgrade graphql --latest  

1. Add this npm command to your package.json:

   "scripts": {
       "rcp": "NODE_ENV=production relay-compiler-plus --schema <SCHEMA_FILE_PATH> --src <SRC_DIR_PATH>"
   },
   

   where

   • <SCHEMA_FILE_PATH> is the path to your schema.graphql or schema.json file or schema.js (yes! rcp now supports direct compilation from graphql-js!).
   • <SRC_DIR_PATH> is the path to your src directory

   then:

   npm run rcp
   

   this should generate:

   • query files (*.graphql.js) containing query ids and null query text. Note that if you omit NODE_ENV=production, rcp will include both the query id and the query text in your query files. This can be useful for debugging in development.
   • A queryMap.json file under <SRC_DIR_PATH>/queryMap.json. This file can be consumed by the server to map the query ids to actual queries.
   • If you specified a schema.js file, this will also generate a schema.graphql file under ../<SRC_DIR_PATH>/schema.graphql. The schema.graphql has to sit outside the src folder otherwise the relay-compiler will complain.

   If your graphql-js file is complex and you need to override the default webpack config you can do so like this:

   "scripts": {
       "rcp": "NODE_ENV=production relay-compiler-plus --webpackConfig <WEBPACK_CONFIG_PATH> --src <SRC_DIR_PATH>"
   },
   

   where

   • <WEBPACK_CONFIG_PATH> is the path to your custom webpack config to transpile your graphql-js schema. In your custom webpack config, you need to set output.libraryTarget: 'commonjs2'. See the example config for a working copy.

2. On the server, use matchQueryMiddleware prior to express-graphql to match queryIds to actual queries. Note that queryMap.json is auto-generated by relay-compiler-plus at step 1.

   import Express from 'express';
   import expressGraphl from 'express-graphql';
   import {matchQueryMiddleware} from 'relay-compiler-plus'; // do this
   import queryMapJson from '../queryMap.json'; // do this
   
   const app = Express();
   
   app.use('/graphql',
     matchQueryMiddleware(queryMapJson), // do this
     expressGraphl({
       schema: graphqlSchema,
       graphiql: true,
     }));

3. On the client, modify your relay network fetch implementation to pass a queryId parameter in the request body instead of a query parameter. Note that operation.id is generated by relay-compiler-plus in step 1.

   function fetchQuery(operation, variables) {
     return fetch('/graphql', {
       method: 'POST',
       headers: {
         'content-type': 'application/json'
       },
       body: JSON.stringify({
         queryId: operation.id, // do this
         variables,
       }),
     }).then(response => {
       return response.json();
     });
   }

Run your app and that's it!

Check the example for a fully working demo.