GraphQL-Tools-Subscribe

Subscription Framework for GraphQL-Tools

About

This Node.js module provides a subscription framework for GraphQL Tools or plain GraphQL.js which allows GraphQL clients to subscribe on their query and find out whether their previously subscribed queries should be refetched. The framework is designed to allow an arbitrary subscription persistence handling and this way let GraphQL servers to perform additional tasks like publishing the subscription ids of outdated queries (usually by means of a parallel WebSocket connection).

Installation

$ npm install graphql-tools-subscribe

Application Programming Interface (API)

See the TypeScript type definition of the GraphQL-Tools-Subscribe API for details.

Usage Example

import GTS from "graphql-tools-subscribe"

let gts = new GTS({ pubsub: "spm", keyval: "spm" })
gts.open()
let gtsConn = gts.connection("dummy", (sids) => {
    console.log("OUTDATED", sids)
})
gts.on("debug", (msg) => {
    console.log("DEBUG", msg)
})
[...]

let Foo = {}
[...]

let definition = `
    schema {
        query:    Root
        mutation: Root
    }
    type Root {
        ${gts.schemaSubscription()}
        [...]
    }
    type _Subscription {
        ${gts.schemaSubscriptions()}
        ${gts.schemaSubscribe()}
        ${gts.schemaUnsubscribe()}
        ${gts.schemaPause()}
        ${gts.schemaResume()}
    }
    [...]
}
let resolvers = {
    Root: {
        _Subscription: gts.resolverSubscription()
    },
    _Subscription: {
        subscribe:     gts.resolverSubscribe(),
        unsubscribe:   gts.resolverUnsubscribe(),
        subscriptions: gts.resolverSubscriptions(),
        pause:         gts.resolverPause(),
        resume:        gts.resolverResume()
    },
    Foo: {
        get: (obj, args, ctx, info) => {
            let key = args.key
            let val = Foo[key]
            ctx.scope.record({
                op: "read", arity: "one",
                dstType: "Foo", dstIds: [ "Foo" ], dstAttrs: [ key ]
            })
            return val
        },
        set: (obj, args, ctx, info) => {
            let key = args.key
            let val = args.val
            foo[key] = val
            ctx.scope.record({
                op: "update", arity: "one",
                dstType: "Foo", dstIds: [ "Foo" ], dstAttrs: [ key ]
            })
            return null
        },
        [...]
    }
    [...]
}
let schema = GraphQLTools.makeExecutableSchema({
    typeDefs: [ definition ],
    resolvers: resolvers
})

[...]
[...]((query, variables) => {
    let scope = gtsConn.scope(query, variables)
    ctx.scope = scope
    await GraphQL.graphql(schema, query, null, ctx, variables).then((result) => {
        scope.commit()
        [...]
    }).catch((result) => {
        scope.reject()
        [...]
    })
})

For a real example, see sample script

See Also

• Specification: GraphQL Subscriptions
• Article: GraphQL Subscriptions
• Article: GraphQL Subscriptions in Apollo Client
• Article: GraphQL Subscriptions in GraphiQL
• Article: GraphQL Subscriptions Proposal
• Documentation: Apollo Client, GraphQL Subscriptions
• Documentation: GraphQL Tools, GraphQL Subscriptions
• Module: Apollo Client, GraphQL Subscriptions
• Module: Apollo Client, GraphQL Transport WebSocket

Assumptions

It is assumed that you define the GraphQL scalar type UUID and Void with the help of GraphQL-Tools-Types:

import GraphQLToolsTypes from "graphql-tools-types"
...
let definition = `
    scalar Void
    scalar UUID
    ...
`
let resolvers = {
    Void:     GraphQLToolsTypes.Void({ name: "Void" }),
    UUID:     GraphQLToolsTypes.UUID({ name: "UUID", storage: "string" }),
    ...
}

License

Copyright (c) 2016-2019 Dr. Ralf S. Engelschall (http://engelschall.com/)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.