node-red-contrib-graphql

A NodeRed node to execute GraphQL Queries.

Change Log

GraphQL Nodes

Provides a GraphQL node to support queries and a configuration node called graphql-server.

graphql-server Configuration Node Fields

graphql Function Node Fields

Countries API Example

This example flow uses the node-red-contrib-graphql node to query the Countries API built by GitHub user Trevor Blades.

The example flow is in the file examples/countries.json. Import this file from the clipboard under the NodeRed menu Import > Clipboard. You'll drag the example flow onto NodeRed.

Edit graphql node

The GraphQL endpoint for is https://countries.trevorblades.com/. You can try it out here. Here's the graphql-node:

GraphQL Output

This is the result sent to the debug window.

Authentication Example

A bearer token can be provided for authentication. This is an example using the GitHub GraphQL API which is documented here.

Config Node Token

If you have an token with a long life, you can provide the token in the graphql-server configuration node. For GitHub, user your GitHub PAT.

You can also provide the token in the graphql node. This is useful if a prior node performs the authentication and returns the token to be used for a limited session.

Custom Headers

You can provide custom headers to the GraphQL node by attaching a customHeaders key to the msg and passing that to the GraphQL node. Here's an example that sets the content-type and a bearer token.

Templates and Variable Use

There are two template flavors:

1. Plain
2. Mustache

At the bottom of the template text area, you must select between plain or mustache template.

If you select mustache, your template will be processed by Mustache with the message's payload as an argument. I.e.

submitted_template = mustache("template in text area", msg.payload)

If you select plain, the template is left as it is.

Template variables

You can add GraphQL query variables to the submitted query by defining them in the msg.variables property. Your variables will be passed over to the GraphQL query.

For example, if you define

type Response {
  ok: boolean
}

input doSomethingInput {
  myVar: String
}

type Mutation {
  doSomething(input: doSomethingInput!): Response
}

you can pass the messageInput parameter as such in Node-Red msg:

msg.variables = {
  "input": {
    "myVar": "myValue"
  }
}

it will be added to the GraphQL query:

query: `mutation doSomething($input: messageInput!) {
  doSomething(input: $input) {
    ok
  }
}`,
variables: {
  input: {
    myVar: "myValue"
  }
}

When using a scalar type like JSON, the entire payload can conveniently be passed as an input parameter:

scalar JSON

type Response {
  ok: boolean
}

input payloadInput {
  payload: JSON
}

type Mutation {
  doSomething(input: payloadInput!): Response
}

In node-red flow, prepare payloadInput variables:

msg.variables = {
  "input": {
    "payload": msg.payload
  }
}

which will results in

query: `mutation doSomething($input: payloadInput!) {
  doSomething(input: $input) {
    ok
  }
}`,
variables: {
  input: {
    myVar: { whatever: "was in you msg.payload", val: 5, bool: true }
  }
}

The execution will return the value in:

msg.payload.doSomething

object.

Outputs

payload is loaded with the output of the Query or Mutation. If the Query is named doSomething, the results of the query will be in payload.doSomething.

//msg.payload is:
{
  doSomething: {
    ok: true
  }
}