arrest
v13.2.5
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OpenAPI v3 compliant REST framework for Node.js, with support for MongoDB and JSON-Schema
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arrest
Swagger REST framework for Node.js, with support for MongoDB and JSON-Schema
Arrest lets you write RESTful web services in minutes. It automatically generates a Swagger description of the API and support input validation using JSON-Schemas.
Highlight features:
- Compatible with Express 4.x
- Implements simple CRUD semantics on MongoDB
- Supports querying object with the RQL syntax
- Input validation with JSON-Schema
- Oauth2 scope checks per operation
Note for 1.3 users: arrest 3.x is a complete rewrite of the old module and it's not backwards compatible.
How to Install
npm install arrest
Super Simple Example
The following sample application shows how to create a simple REST API, using a MongoDB collection as the data store. In the sample, the path /tests is linked to a tests collection on a MongoDB instance running on localhost:
const arrest = require('arrest');
const api = new arrest.API();
api.addResource(new arrest.MongoResource('mongodb://localhost:27017', { name: 'Test' }));
api.listen(3000);
The Swagger specification of the API you just created is available at http://localhost:3000/swagger.json
Now you can query your data collection like this:
curl "http://localhost:3000/tests"
You can add a new item:
curl "http://localhost:3000/tests" -H "Content-Type: application/json" -X POST -d '{ "name": "Jimbo", "surname": "Johnson" }'
You can query a specific item by appeding the identifier of the record (the _id attribute):
curl "http://localhost:3000/tests/51acc04f196573941f000002"
You can update an item:
curl "http://localhost:3000/tests/51acc04f196573941f000002" -H "Content-Type: application/json" -X PUT -d '{ "name": "Jimbo", "surname": "Smith" }'
And finally you can delete an item:
curl "http://localhost:3000/tests/51acc04f196573941f000002" -X DELETE
Creating an API
An API is a collection of Resources, each supporting one or more Operations.
In arrest you create an API by creating an instance of the base API
class or of a derived class.
You then add instances of the Resource
class or a derived one. Each resource contains its supported Routes
, that is
a collection of instances of classes derived from the abstract Operation
, which represents an operation to be executed
when an HTTP method is called on a path.
The following code demonstrates this three level structure:
const arrest = require('arrest');
const api = new arrest.API();
const operation1 = function(req, res, next) {
res.json({ data: 'this is operation 1' });
}
const operation2 = function(req, res, next) {
res.json({ data: 'this is operation 2' });
}
const operation3 = function(req, res, next) {
res.json({ data: 'this is operation 3' });
}
const resource1 = new arrest.Resource({
name: 'SomeResource',
routes: {
'/': {
get: operation1,
post: operation2
},
'/some-path': {
put: operation3
}
}
})
api.addResource(resource1);
api.listen(3000);
The API above supports the following operations:
GET
onhttp://localhost/some-resources
POST
onhttp://localhost/some-resources
PUT
onhttp://localhost/some-resources/some-path
Please note how the some-resources path was automatically constructed using the name of the resource SomeResource
, making
it plural and converting the camelcase in a dash-separated name. This default behaviour can be changed specifying the
namePlural and path when creating the resource (e.g. new Resource({ name: 'OneResource', namePlural: 'ManyResources', path: 'my_resources' })
)
Another other way to produce the same result is:
const arrest = require('arrest');
const api = new arrest.API();
const resource1 = new arrest.Resource({ name: 'SomeResource' });
resource1.addOperation('/', 'get', function(req, res, next) {
res.json({ data: 'this is operation 1' });
});
resource1.addOperation('/', 'post', function(req, res, next) {
res.json({ data: 'this is operation 2' });
});
resource1.addOperation('/some-path', 'put', function(req, res, next) {
res.json({ data: 'this is operation 3' });
});
api.addResource(resource1);
api.listen(3000);
In real world applications, where resources and operation are in fact more complex, you will want to create class that extend the basic classes in arrest, like in the next example:
const arrest = require('arrest');
class MyOperation extends arrest.Operation {
constructor(resource, path, method) {
super('op1', resource, path, method);
}
handler(req, res, next) {
res.json({ data: 'this is a custom operation' });
}
}
class MyResource extends arrest.Resource {
constructor() {
super();
this.addOperation(new MyOperation(this, '/', 'get'));
}
}
class MyAPI extends arrest.API {
constructor() {
super({
info: {
title: 'This is a custom API',
version: '0.9.5'
}
});
this.addResource(new MyResource());
}
}
const api = new MyAPI();
api.listen(3000);
The API above supports GET
s on http://localhost/my-resources
(note how the path was in this case constructed automatically
from the name of the class MyResource).
By the default, arrest APIs add a special route /swagger.json
that returns the Swagger description of the API: the Swagger
object is populated with the properties of the API object, Resources are converted into Swagger Tags and Operations are
mapped to Swagger Operations.
Data validation
arrest supports JSON-Schema for data validation. Validation rules are set using the Swagger specification. For instance,
the following code show how to validate the body of a POST
and the query paramters of a GET
:
class MyOperation1 extends arrest.Operation {
constructor(resource, path, method) {
super('op1', resource, path, method);
this.setInfo({
parameters: [
{
name: 'body',
in: 'body',
required: true,
schema: {
type: 'object',
required: [ 'name' ],
additionalProperties: false,
properties: {
name: {
type: 'string'
},
surname: {
type: 'string'
}
}
}
}
]
});
}
handler(req, res, next) {
res.json({ data: 'this is a op1' });
}
}
class MyOperation2 extends arrest.Operation {
constructor(resource, path, method) {
super('op2', resource, path, method);
this.setInfo({
parameters: [
{
name: 'lang',
in: 'query',
type: 'string',
required: true
},
{
name: 'count',
in: 'query',
type: 'integer'
}
]
});
}
handler(req, res, next) {
res.json({ data: 'this is a op2' });
}
}
class MyResource extends arrest.Resource {
constructor() {
super();
this.addOperation(new MyOperation1(this, '/', 'post'));
this.addOperation(new MyOperation2(this, '/', 'get'));
}
}
Omitting the body or passing an invalid body (e.g. an object without the name property) when POST
ing to
http://localhost/my-resources
will return an error. Likewise GET
ting without a lang parameter or with a count
set to anything other than a number will fail.
Scopes and security validators
TBA
Creating an API with a MongoDB data store
TBA (default api routes)
Using arrest with express
TBA
Debugging
TBA
API documentation
TBA