Senegraph

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Do you like Microservices?
Do you like GraphQL?

Me too! Let me then propose this simple plugin for HapiJS and Express Middleware to you. It's fairly simple and flexible tool for creating API endpoints.

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``
npm install --save senegraph
`

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##### HAPI JS :
Here is a simple setup for HapiJS:

`javascript
import * as hapi from 'hapi';
import { senegraphHapi, hapiql } from 'senegraph';

// setup Hapi server
const server = new hapi.Server();
server.connection({ port: 3000 });

// register the plugins
server.register([{
register: senegraphHapi,
options: senegraphOptions,
}, {
register: hapiql,
options: {
path: '/graphiql' // Optional default '/graphiql'
hapiqlOptions: {
endpointURL: '/graphql', // required - pointing to the graphQL route
},
},
}], (err) => {
if(err) {
throw err;
}
server.start((error) => {
if (error) {
throw error;
}
server.log('info', Server running at: ${server.info.uri});
});
});
`

Now the senegraphOptions variable can look like this:

`javascript
const senegraphOptions = {
// Setting up the seneca microservices
setupSeneca: (seneca) => {
// we can return a promise if we need it
// to wait for some async operation
seneca.add({ role: 'greeter', cmd: 'sayHello' }, (message, done) => {
if(message.user) {
done(null, { message: 'Hello ' + message.user });
} else {
done(new Error('You forgot to tell me who you are'));
}
});
},
// Setting up the schema (for this example it's pretty simple
// but you can for example split it into multiple modules
schema:
type Query {
hello(name: String!): String
}
,
resolvers: {
Query: {
// third argument is context, which contains
// the seneca that we can use for our purpose
hello: (root, { name }, { seneca }) => {
// we need to use promise
// but we could use bluebird's Promisify
// on seneca, check the links below
return new Promise((resolve, reject) => {
seneca.act({
role: 'greeter',
cmd: 'sayHello',
user: name,
}, (err, greetings) => {
if(err) {
reject(err);
} else {
resolve(greetings.message);
}
});
});
}
}
}
}
`

To split the schema and/or resolvers into multiple modules take a look at this:
http://dev.apollodata.com/tools/graphql-tools/generate-schema.html#modularizing

To modularize SenecaJS into multiple files take a look at this:
http://jakepruitt.com/2015/02/09/beginners-guide-to-seneca-js.html

To promisify seneca take a look at this:
http://senecajs.org/docs/tutorials/seneca-with-promises.html

-----------------

What if you need to make action for every request called upon your graphql
endpoint? What if you need to provide some additional context and/or root value
for your resolvers?

Here's how you do that:

`javascript
const senegraphOptions = {
schema: mySchema,
resolvers: {
Query: {
hello: ({ myRootData }, args, { seneca, myContextData }) => {
// use myRootData = 'random data2' and myContextData = 'random data1'
return 'world';
}
}
},
// This function is called before every request
// on your graphql endpoint:
perRequest: (seneca) => {
// It can either return a value or a Promise
return new Promise((resolve) => {
setTimeout(() => {
resolve({
// returns context and rootValue used in the next graphql call
context: { myContextData: 'random data1' },
rootValue: { myRootData: 'random data2' },
});
}, 200);
});
}
}
`

cool isn't it? You can do for example authentication on every single request.

API

SenegraphHapi options:

| option | type | description | required |
|:-------------:|:----------------------------------------------------------------:|:-------------------------------------------------------------------------------------------------------------------------------------:|:------------------------------:|
| schema | String! | | true |
| resolvers | Object! or Array | Containing the resolvers of your graphql schema. | true |
| path | String | The url for the endpoint route. | false Default: '/graphql' |
| methods | String | Array | The methods supported for graphql endpoint | false Default: ['GET', 'POST'] |
| setupSeneca | Function (seneca) => {} | Is being called at the beginning. This option is optional. | false |
| perRequest | Promise