@neode/express

The idea behind this repository is remove the CRUD boilerplate around Express applications interacting with Neo4j by providing a simple API to build Resource Controller around your neode models.

Usage

With one extra dependency and one line of code, you can quickly add a set of REST endpoints.

Say for example, you have a graph of (:User)s and their (:Skill)s - you would have a models directory with two files:

• User.js
• Skill.js

Then index.js would look a little like this:

const express = require('express')
const bodyParser = require('body-parser')

const neode = require('neode')
    .fromEnv()
    .withDirectory(__dirname +'/models')

const app = express()

app.use(bodyParser.json())
// ...

By adding two lines, you can create a set of REST endpoints that use the information defined in the Neo4j models to validate and process the requests.

const resource = require('@neode/express')

app.use('/api/users', resource(neode, 'User'))

The resource function

This takes two arguments, first your neode instance, and secondly the name of the model. That's it. You'll be able to GET /api/users to retrieve a list of User nodes, POST /api/users to create a new user, GET /api/users/{primary key} to view an individual resource PUT /api/users/{primary key} to update the node, and DELETE /api/users/{primary key} to delete the node.

Endpoints

GET / - List

The list endpoint will return a paginated list of nodes. The list can be filtered based on any property that is listed in the model definition as an index, unique or a primary key. All you need to do is pass it as part of the query string.

Key | Action | Notes -- | -- | -- order | Property name to order by sort | Order to return the records | asc or desc limit | Number of records to return | Default is 10 page | Page number to return | Offset is calculated as page-1 * limit

POST / - Create

Posting to the root will attempt to create a node based on the neode model definition. If any validation fails, the server wll return a 422 status code and an object including details - a list of the Joi validation errors.

This takes a combination of the post body and request params - so for example, you could define the primary key of the parent object into the URL.

// Post.js
module.exports = {
    body: 'string',
    user: {
        type: 'node',
        target: 'User',
        relationship: 'POSTED',
        direction: 'in',
    },
}

// Resource
api.use('/api/users/:user/posts', resource(neode, 'Post'))

// Application call
axios.post('http://localhost:3000/api/users/user', { data: { content: 'Lorem ipsum' } })

This would take the :user value from the URL, combine it with data in the request and pass the info through to neode.create().

GET /:id Show

A GET request to /{id} will attempt to load the model with the primary key {id}. The primary key is defined as the primary: true in the model definition. The properties and relationships defined with eager: true will be returned as a JSON object.

PUT /:id - Update

A PUT request to /{id} will attempt to load the model with the primary key {id}, then use a combination of the request params and post body to update the node.

DELETE /:id - Destroy

A PUT request to /{id} will attempt to load the model with the primary key {id}, then delete it via neode - including any cascade deletion defined in the model.