egg-rest
v2.1.0
Published
Restful API plugin for egg
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egg-rest
RESTful API plugin for Egg.
Developing RESTful API with egg-rest is very simple. You may read JSON API spec first.
Install
$ npm i egg-rest --save
Usage
Enable the rest plugin in plugin.js
:
exports.rest = {
enable: true,
package: 'egg-rest',
};
Configuration
urlprefix
: Prefix of rest api url. Default to/api/
authRequest
: a function for getting some value of authenticationauthIgnores
: allow some request to ignore authenticationerrorResponse
: Error handling function
Example: Configure the rest plugin in config/config.default.js
:
exports.rest = {
urlprefix: '/doc/api/', // Prefix of rest api url. Default to /api/
authRequest: null,
// authRequest: async ctx => {
// // A truthy value must be returned when authentication succeeds.
// // Otherwise the client will be responded with `401 Unauthorized`
// return accessToken;
// }
// Specify the APIs for which authentication can be ignored.
// If authRequest is configured, authentication for all APIs is required by default.
authIgnores: null,
// authIgnores: {
// users: {
// show: true, // allow GET /api/users/:id to ignore authentication
// index: true,
// }
// }
};
Controllers in files matching ${baseDir}/app/api/**.js
will be loaded automatically according to routing rules.
Caution
If your RESTful API is open to public systems or websites, you should disable [ctoken] security validation, which is provided by security plugin, for your RESTful url prefix:
exports.security = {
ignore: '/doc/api/'
};
URL Routing
Follow the naming conventions of rails:
method | url | file path | controller name
--- | --- | --- | ---
GET | /doc/api/{objects}[?per_page={per_page}&page={page}]
| app/api/{objects}.js
| index()
GET | /doc/api/{objects}/:id
| app/api/{objects}.js
| show()
POST | /doc/api/{objects}
| app/api/{objects}.js
| create()
PUT | /doc/api/{objects}/:id
| app/api/{objects}.js
| update()
DELETE | /doc/api/{objects}/:id[s]
| app/api/{objects}.js
| destroy()
Nested Resources
Nesting of two layer at most is supported.
method | url | file path | controller name
--- | --- | --- | ---
GET | /doc/api/{parents}/:parent_id/{children}/:child_id/{objects}?per_page={per_page}&page={page}
| app/api/{parents}/{objects}.js
| index()
GET | /doc/api/{parents}/:parent_id/{children}/:child_id/{objects}/:id
| app/api/{parents}/{objects}.js
| show()
POST | /doc/api/{parents}/:parent_id/{children}/:child_id/{objects}
| app/api/{parents}/{objects}.js
| create()
PUT | /doc/api/{parents}/:parent_id/{children}/:child_id/{objects}/:id
| app/api/{parents}/{objects}.js
| update()
DELETE | /doc/api/{parents}/:parent_id/{children}/:child_id/{objects}/:id[s]
| app/api/{parents}/{objects}.js
| destroy()
Example: /api/users/3/posts/1/replies/2
=> params: { parent_id: 3, child_id: 2, id: 1 }
. The idea is that you can can retrieve the ids from this.params
,
which you get values of { users: '3', posts: '1', replies: '2' }
. It matches the file path /api/users/3/posts/1/replies/2
.
Note: It does not support more than three level deep nesting. Example: /api/users/3/posts/1/replies/2/answer
won't match file path
api/users/posts/replies/answer.js
. Currently, it can only retrieve maximum three query parameters.
Controllers can be loaded from index.js
in parent directory.
Example: /doc/api/{parents}
=> app/api/{parents}/index.js
Resource Conventions
All RESTful API must and will respond data with JSON format, following the JSON API spec.
A JSON object MUST be at the root of every JSON API request and response containing data. This object defines a document’s “top level”.
A document MUST contain at least one of the following top-level members:
- meta: a meta object that contains non-standard meta-information, eg. paging info
- links: a links object related to the primary data.
- linked: resource objects linked in a relationship. When fetched, the related resource object(s) are returned as the response’s primary data.
- data: the document’s “primary data”
Primary data MUST be either:
- a single resource object, a single resource identifier object, or null, for requests that target single resources
- an array of resource objects, an array of resource identifier objects, or an empty array ([]), for requests that target resource collections
Why should we use the 'data' field as the entry of accessing primary data, instead of respond with it directly? In same cases, such as searching API, paging meta info is required other than primary data.
Single Resource Object
Here’s how an post (i.e. a resource of type “post”) might appear in a document:
{
"data": {
"id": "1",
// ... attributes of this post
}
}
Represent the post with just an id:
{
"data": "1"
}
Resource Collection
{
"data": [{
"id": "1"
// ... attributes of this post
}, {
"id": "2"
// ... attributes of this post
}],
"meta": {
"count": 100 // totol number of posts
}
}
Represent posts with an array of post Ids:
{
"data": ["1", "2"]
}
Resource Fields
Four reserved fields:
- "id"
- "type"
- "href"
- "links"
Resource Searching GET /doc/api/{objects}[?page={page}&per_page={per_page}]
Request
GET /doc/api/users?per_page=2
Accept: application/json
Controller
Controller exports.index
will be loaded automatically.
Paging params must be accessed by this.params.page
and this.params.per_page
.
And both of them must be numbers.
// app/api/user.js
// routing: GET /doc/api/users
exports.index = function* (next) {
// coding as a common controller
var users = yield uic.listUser({limit: this.params.per_page});
// totol number of users
var total = yield uic.total();
// set meta info
this.meta = {
total: total
};
this.data = users;
};
Response
200 OK
: the resource exists, accessing it successfully
HTTP/1.1 200 OK
Content-Type: application/json
{
"data": [{
"id": 1024,
"name": "shaoshuai0102",
"mobile": '186xxxxxxxx'
}, {
"id": 1025,
"name": "fengmk2",
"mobile": '186xxxxxxxx'
}],
"meta": {
"total": 100000
}
}
Fetching One Single Resource Document GET /doc/api/{objects}/:id
Request
GET /doc/api/users/1024
Accept: application/json
Controller
Controller exports.show
will be loaded automatically.
// app/api/user.js
// routing: GET /doc/api/users/:id
exports.show = function* (next) {
// coding as a common controller
var user = yield uic.getUser(this.params.id);
if (!user) {
return yield* next;
}
this.data = user;
};
Response
200 OK
: the resource exists, accessing it successfully
HTTP/1.1 200 OK
Content-Type: application/json
{
"data": {
"id": 1024,
"name": "苏千",
"mobile": '186xxxxxxxx'
}
}
Fetching A Resource Collection GET /doc/api/{objects}/:ids
Request
GET /doc/api/users/:ids
, multiple ids are seperated with comma.
GET /doc/api/users/1024,10,111
Accept: application/json
Controller
Controller exports.show
will be loaded automatically.
Multiple id can be accessed with this.params.ids
as an array, if you want to support multiple id.
// app/api/user.js
// routing: GET /doc/api/users/:ids
exports.show = function* (next) {
// coding as a common controller
const users = yield userService.listUsers(this.params.ids);
this.data = users;
};
Response
200 OK
: the resource exists, accessing it successfully
HTTP/1.1 200 OK
Content-Type: application/json
{
"data": [{
"id": 1024,
"name": "fengmk2",
"mobile": '186xxxxxxxx'
}, {
"id": 10,
"name": "shaoshuai0102",
"mobile": '186xxxxxxxx'
}]
}
Creating Resources POST /doc/api/{objects}
Request
Must be a POST
request:
POST /doc/api/users
Content-Type: application/json
Accept: application/json
{
"name": "fengmk2",
"mobile": '186xxxxxxxx'
}
Controller
Controller exports.create
will be loaded automatically.
// app/api/user.js
// Routing: POST /doc/api/users
exports.create = function* (next) {
var newUser = this.params.data;
var user = yield userService.create(newUser);
this.data = user;
};
Response
When resource document is created successfully, 201 Created
is returned, with the created document as the body.
HTTP/1.1 201 Created
Content-Type: application/json
{
"data": {
"id": 1024,
"name": "fengmk2",
"mobile": '186xxxxxxxx'
}
}
Updating Resources PUT /doc/api/{objects}/:id
Request
Must be a PUT
request.
In the example below, only mobile
field is updated:
PUT /doc/api/users/1024
Content-Type: application/json
Accept: application/json
{
"mobile": '186xxxxxxxx'
}
Controller
Controller exports.update
is loaded automatically.
// app/api/user.js
// Routing: PUT /doc/api/users/:id
exports.update = function* (next) {
var user = this.params.data;
yield userService.update(user);
};
Response
204 No Content
: when an update is successful and the server doesn’t update any attributes besides those provided, the server MUST return204 No Content
without the document.
HTTP/1.1 204 No Content
200 OK
: If a server accepts an update but also changes the resource(s) in ways other than those specified by the request (for example, updating the updated-at attribute or a computed sha), it MUST return a 200 OK response. The response document MUST include a representation of the updated resource(s) as if a GET request was made to the request URL.
HTTP/1.1 200 OK
Content-Type: application/json
{
"data": {
"id": 1024,
"name": "fengmk2",
"mobile": '186xxxxxxxx'
}
}
Deleting Resources DELETE /doc/api/{objects}/:id[s]
Request
- Deleting one single resource document
DELETE /doc/api/users/1024
- Deleting multiple resource documents
DELETE /doc/api/users/1024,100,100023
Controller
Controller exports.destroy
will be loaded automatically.
Multiple id can be accessed with this.params.ids
as an array, if you want to support multiple id.
// app/api/user.js
// Routing: DELETE /doc/api/users/:id
exports.destroy = function* (next) {
yield userService.update(this.params.id);
// or `this.params.ids` for multiple id
};
Response
204 No Content
: If a server deletes the document(s) successfully, it MUST return204 No Content
.
HTTP/1.1 204 No Content
Errors
An error object is a special resource, with additional information about problems encountered while performing an operation.
Semantic Status Code
Success codes
201 Created
should be used when creating content (INSERT),202 Accepted
should be used when a request is queued for background processing (async tasks),204 No Content
should be used when the request was properly executed but no content was returned (a good example would be when you delete something).
Client error codes
400 Bad Request
should be used when there was an error while processing the request payload (malformed JSON, for instance).401 Unauthorized
should be used when a request is not authenticiated (wrong access token, or username or password).403 Forbidden
should be used when the request is successfully authenticiated (see 401), but the action was forbidden.406 Not Acceptable
should be used when the requested format is not available (for instance, when requesting an XML resource from a JSON only server).410 Gone
Should be returned when the requested resource is permenantely deleted and will never be available again.422 Unprocesable entity
Could be used when there was a validation error while creating an object.
Server error codes
500 Internal Server Error
should be used when server unexpected error happend.
A more complete list of status codes can be found in RFC2616.
Server Error(5xx) Example
Usually detailed error information will be hidden in production to prevent security issues for code leaking
Detailed error information can be found in $HOME/logs/$APPNAME/common-error.log
.
HTTP/1.1 500 Server Error
{
"message": "Internal Server Error"
}
Detailed infomation will be returned in development. It's helpful when developing and debuging.
{
"message": "TypeError: foo.bar is undefined",
"stack": "TypeError: foo.bar is undefined\n at Object.checkAuth (/Users/..."
}
Client Error(4xx) Example
Ref: https://developer.github.com/v3/#client-errors
404
https://api.github.com/gists/df2d46e24563df97cd9b
HTTP/1.1 404 Not Found
{
"message": "Not Found",
"documentation_url": "https://developer.github.com/v3"
}
400
There's a problem when parsing the recieved data as JSON.
HTTP/1.1 400 Bad Request
{
"message": "Problems parsing JSON"
}
The recieved data is not a JSON object.
HTTP/1.1 400 Bad Request
{
"message": "Body should be a JSON object"
}
422 Unprocessable Entity
Param validation failed.
HTTP/1.1 422 Unprocessable Entity
{
"message": "Validation Failed",
"errors": [
{
"field": "username",
"code": "missing_field",
"message": "username required"
}
]
}
401 Unauthorized
Authorization failed
$ curl -i localhost/doc/api/users/1 -u foo:bar
HTTP/1.1 401 Unauthorized
{
"message": "Bad credentials"
}
User-Agent is Required
https://developer.github.com/v3/#user-agent-required
$ curl -iH 'User-Agent: ' https://api.github.com/meta
HTTP/1.0 403 Forbidden
{
"message": "Please make sure your request has a User-Agent header"
}
Parameter Validation
Rest plugin provides a way of validating request params.
For more details of validating rules, see parameter.
createRule
和 updateRule
// Specify validation rules of create request
// If failed, '422' will be returned automatically
exports.createRule = {
username: 'email',
password: {
type: 'password',
compare: 're-password'
},
age: {
type: 'int',
required: false
}
};
exports.create = function* () {
var user = this.params.data;
// handle user
};
// Specify validation rules of create request
exports.updateRule = {
age: {
type: 'int',
required: false
}
};
exports.update = function* () {
};
Validation failure example:
HTTP/1.1 422 Unprocessable Entity
{
"message": "Validation Failed",
"errors": [
{
"field": "username",
"code": "invalid",
"message": "username should be an email"
},
{
"field": "password",
"code": "missing_field",
"message": "password required"
},
{
"field": "age",
"code": "invalid",
"message": "age should be an integer"
}
]
}
Execute Validation Manually
In most cases, the automatic way above is just fine.
But sometimes we need do the validation manualy.
So we can use this.validate(rules[, data])
var createRule = {...};
exports.create = function* () {
var user = this.params.data;
// If validation failed, status 422 will be returned
this.validate(createRule, user);
// handle user
};
Custom Authentication
If you want to add request authentication, configure it with rest.authRequest
in config/config.default.js
:
exports.rest = {
enable: true,
authIgnores: {
// allow users.show() and users.index() to ignore authentication
users: {
show: true,
index: true
}
},
authRequest: function* (ctx) {
if (ctx.query.private_token === 'admintoken-123') {
// If authentication succeeds, the info returned below can be accessed with `this.accessToken` in controller.
return {
name: 'admin'
};
}
// authentication failure
return null;
}
};
For user.create()
, user.update()
and user.destroy()
, they will be invoked only after passing authentication.
Authentication failure response:
HTTP/1.1 401 Unauthorized
{
"message": "Bad credentials"
}
Ref
- JSON API Spec
- REST: Representational State Transfer
- ome REST best practices
- Restful routing using resourceful and director
- Rails Routing from the Outside In
- HTTP API design guide extracted from work on the Heroku Platform API
- ctoken