finale-rest

v1.2.2

Published

8 months ago

Create REST resources and controllers with Sequelize and Express or Restify

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tommybananas

sequelize sequelizejs rest restful finale json api

Finale

Create flexible REST endpoints and controllers from Sequelize models in your Express or Restify app.

This project aims to be a Sequelize 4.x and 5.x compatible version of Epilogue.

Installation

npm install finale-rest

Getting Started

var Sequelize = require('sequelize'),
    finale = require('finale-rest'),
    http = require('http');

// Define your models
var database = new Sequelize('database', 'root', 'password');
var User = database.define('User', {
  username: Sequelize.STRING,
  birthday: Sequelize.DATE
});

// Initialize server
var server, app;
if (process.env.USE_RESTIFY) {
  var restify = require('restify');
  var corsMiddleware = require('restify-cors-middleware');
  
  app = server = restify.createServer()
  var cors = corsMiddleware({
    preflightMaxAge: 5, // Optional
    origins: ['*'], // Should whitelist actual domains in production
    allowHeaders: ['Authorization', 'API-Token', 'Content-Range'], //Content-range has size info on lists
    exposeHeaders: ['Authorization', 'API-Token-Expiry', 'Content-Range']
  })

  server.pre(cors.preflight)
  server.use(cors.actual)

  server.use(restify.plugins.queryParser()); //{mapParams: true}
  server.use(restify.plugins.bodyParser());  //{mapParams: true, mapFiles: true}
  server.use(restify.plugins.acceptParser(server.acceptable));
} else {
  var express = require('express'),
      bodyParser = require('body-parser');

  var app = express();
  app.use(bodyParser.json());
  app.use(bodyParser.urlencoded({ extended: false }));
  server = http.createServer(app);
}

// Initialize finale
finale.initialize({
  app: app,
  sequelize: database
});

// Create REST resource
var userResource = finale.resource({
  model: User,
  endpoints: ['/users', '/users/:id']
});

// Create database and listen
database
  .sync({ force: true })
  .then(function() {
    server.listen(function() {
      var host = server.address().address,
          port = server.address().port;

      console.log('listening at http://%s:%s', host, port);
    });
  });

Migrate from Epilogue

Finale is built to be a drop-in replacement for Epilogue that supports Sequelize 4.x.x

const epilogue = require('epilogue')
epilogue.initialize(...)

// change to

const finale = require('finale-rest')
finale.initialize(...)

Controllers and endpoints

On the server we now have the following controllers and endpoints:

Controller | Endpoint | Description -----------|----------|------------ userResource.create | POST /users | Create a user userResource.list | GET /users | Get a listing of users userResource.read | GET /users/:id | Get details about a user userResource.update | PUT /users/:id | Update a user userResource.delete | DELETE /users/:id | Delete a user

Customize behavior

Of course it's likely that we'll want more flexibility. Our users resource has properties for each of the controller actions. Controller actions in turn have hooks for setting and overriding behavior at each step of the request. We have these milestones to work with: start, auth, fetch, data, write, send, and complete.

var ForbiddenError = require('finale-rest').Errors.ForbiddenError;

// disallow deletes on users
userResource.delete.auth(function(req, res, context) {
    throw new ForbiddenError("can't delete a user");
    // optionally:
    // return context.error(403, "can't delete a user");
})

We can set behavior for milestones directly as above, or we can add functionality before and after milestones too:

// check the cache first
userResource.list.fetch.before(function(req, res, context) {
	var instance = cache.get(context.criteria);

	if (instance) {
		// keep a reference to the instance and skip the fetch
		context.instance = instance;
		return context.skip;
	} else {
		// cache miss; we continue on
		return context.continue;
	}
})

Milestones can also be defined in a declarative fashion, and used as middleware with any resource. For example:

// my-middleware.js
module.exports = {
  create: {
    fetch: function(req, res, context) {
      // manipulate the fetch call
      return context.continue;
    }
  },
  list: {
    write: {
      before: function(req, res, context) {
        // modify data before writing list data
        return context.continue;
      },
      action: function(req, res, context) {
        // change behavior of actually writing the data
        return context.continue;
      },
      after: function(req, res, context) {
        // set some sort of flag after writing list data
        return context.continue;
      }
    }
  }
};

// my-app.js
var finale = require('finale-rest'),
    restMiddleware = require('my-middleware');

finale.initialize({
    app: app,
    sequelize: sequelize
});

var userResource = finale.resource({
    model: User,
    endpoints: ['/users', '/users/:id']
});

userResource.use(restMiddleware);

Finale middleware also supports bundling in extra resource configuration by specifying an "extraConfiguration" member of the middleware like so:

// my-middleware.js
module.exports = {
  extraConfiguration: function(resource) {
    // support delete for plural form of a resource
    var app = resource.app;
    app.del(resource.endpoints.plural, function(req, res) {
      resource.controllers.delete._control(req, res);
    });
  }
};

To show an error and halt execution of milestone functions you can throw an error:

var ForbiddenError = require('finale-rest').Errors.ForbiddenError;

before: function(req, res, context) {
    return authenticate.then(function(authed) {
        if(!authed) throw new ForbiddenError();

        return context.continue;
    });
}

REST API

Listing resources support filtering, searching, sorting, and pagination as described below.

Filtering

Add query parameters named after fields to limit results.

$ curl http://localhost/users?name=James+Conrad

HTTP/1.1 200 OK
Content-Type: application/json

[
  {
    "name": "James Conrad",
    "email": "[email protected]"
  }
]

If your query specifies associations to be included – whether via a model scope (see below), manipulation of Finale's Context object in a custom Milestone handler, or simply by default in your Finale resource definition – your query parameters can reference fields on the joined models, e.g.

$ curl http://localhost/users?group.type=vip

Filtering using scope

Use scope to add additional filtering (More about scopes in sequelize - http://docs.sequelizejs.com/en/latest/docs/scopes/).

  // Define scope in model
  ...
  scope: {
    verified: {
      where : {
        email_verified: true
        phone_verified: true
      }  
    }
  }

$ curl http://localhost/users?scope=verified

HTTP/1.1 200 OK
Content-Type: application/json

[
  {
    "name": "James Conrad",
    "email": "[email protected]"
    "email_verified": true,
    "phone_verified": true
  }
]

Search

Use the q parameter to perform a substring search across all fields.

$ curl http://localhost/users?q=james

HTTP/1.1 200 OK
Content-Type: application/json

[
  {
    "name": "James Conrad",
    "email": "[email protected]"
  }, {
    "name": "Jim Huntington",
    "email": "[email protected]"
  }
]

Search behavior can be customized to change the parameter used for searching, as well as which attributes are included in the search, like so:

var userResource = finale.resource({
    model: User,
    endpoints: ['/users', '/users/:id'],
    search: {
      param: 'searchOnlyUsernames',
      attributes: [ 'username' ]
    }
});

This would restrict substring searches to the username attribute of the User model, and the search parameter would be 'searchOnlyUsernames':

$ curl http://localhost/users?searchOnlyUsernames=james

By default, the substring search is performed using a {field} LIKE '%{query}%' pattern. However, this behavior can be customized by specifying a search operator. Valid operators include: Op.like (default), Op.iLike, Op.notLike, Op.notILike, Op.ne, Op.eq, Op.not, Op.gte, Op.gt, Op.lte, Op.lt. All "*like" operators can only be used against Sequelize.STRING or Sequelize.TEXT fields. For instance:

var userResource = finale.resource({
    model: User,
    endpoints: ['/users', '/users/:id'],
    search: {
      operator: Sequelize.Op.gt,
      attributes: [ 'age' ]
    }
});

When querying against a Sequelize.BOOLEAN field, you'll need to use the Op.eq operator. You can also add multiple search parameters by passing the search key an array of objects:

var userResource = finale.resource({
    model: User,
    endpoints: ['/users', '/users/:id'],
    search: [
      {operator: Sequelize.Op.eq, param: 'emailVerified', attributes: [ 'email_verified' ]},
      {param: 'searchOnlyUsernames', attributes: [ 'username' ]}
    ] 
});

Sorting

Specify the sort parameter to sort results. Values are field names, optionally preceded by a - to indicate descending order. Multiple sort values may be separated by ,.

$ curl http://localhost/users?sort=-name

HTTP/1.1 200 OK
Content-Type: application/json

[
  {
    "name": "Jim Huntington",
    "email": "[email protected]"
  }, {
    "name": "James Conrad",
    "email": "[email protected]"
  }
]

Sort behavior can be customized to change the parameter used for sorting, as well as which attributes are allowed to be used for sorting like so:

var userResource = finale.resource({
    model: User,
    endpoints: ['/users', '/users/:id'],
    sort: {
      param: 'orderby',
      attributes: [ 'username' ]
    }
});

This would restrict sorting to only the username attribute of the User model, and the sort parameter would be 'orderby':

$ curl http://localhost/users?orderby=username

Default sort criteria can be defined with the default attribute. The expected format for default sort criteria is exactly the same as if it was proceeding the sort parameter in the URL.

var userResource = finale.resource({
    model: User,
    endpoints: ['/users', '/users/:id'],
    sort: {
      default: '-email,username'
    }
});

With this configuration, these two calls would result in the same data:

$ curl http://localhost/users
$ curl http://localhost/users?sort=-email,username

Note that the sort parameter in the URL will override your default criteria.

By default all attributes defined on the model are allowed to be sorted on. Sorting on a attribute not allowed will cause a 400 error to be returned with errors in the format:

$ curl http://localhost/users?sortby=invalid,-otherinvalid,valid

HTTP/1.1 400 BAD REQUEST
Content-Type: application/json

{
  "message": "Sorting not allowed on given attributes",
  "errors": ["invalid", "otherinvalid"]
}

Pagination

List routes support pagination via offset or page and count query parameters. Find metadata about pagination and number of results in the Content-Range response header. Pagination defaults to a default of 100 results per page, and a maximum of 1000 results per page.

# get the third page of results
$ curl http://localhost/users?offset=200&count=100

HTTP/1.1 200 OK
Content-Type: application/json
Content-Range: items 200-299/3230

[
  { "name": "James Conrad", ... },
  ...
]

Alternatively, you can specify that pagination is disabled for a given resource by passing false to the pagination property like so:

var userResource = finale.resource({
    model: User,
    endpoints: ['/users', '/users/:id'],
    pagination: false
});

add_to_children on create and update action

For create and update actions, you can provide an add_to_children object to the context. The attributes of add_to_children will be added to all nested child objects sent in the request, overriding any values in the body. This is useful, for example, to inject common attributes from a session, like created_by_user_id or updated_by_user_id, to all children objects in the create body, without having to specify which ones they are specifically. Note: For doing this for top level writes and updates, you can simply specify context.attributes values. add_to_children is just for nested children objects.

finaleResource["create"].write.before(function(req:Request,res:Response,context:any) { 
    let loggedInUserId =  authManager.getLoggedInUserId(req);
    context.add_to_children = {
      updated_by_user_id :  loggedInUserId,
      created_by_user_id :  loggedInUserId
    }
    return context.continue;
  });
}

finaleResource["update"].write.before(function(req:Request,res:Response,context:any) { 
    let loggedInUserId =  authManager.getLoggedInUserId(req);
    context.add_to_children = {
      updated_by_user_id :  loggedInUserId
    }
    return context.continue;
  });
}

This currently is only supported for one level of nesting. It is not recursive.

Deep vs Shallow Payloads

By default, associations are included in read and list payloads. For list and read queries, you can set a shallow boolean on the context to indicate if you want it to include association child objects or not.

userResource["list"].fetch.before(function(req:Request,res:Response,context:any) { 
    context.shallow = true;
    return context.continue;
});

For finer-grain control over which children are included on a per-query basis, you can set context.shallow to true, and also leverage a children query parameter with a pipe-delimited list of associated children to include. children only works if shallow is set to true. The names used in the children query parameter are the as association names when setting up your sequelize models, or the default created by sequelize.

UserModel.belongsToMany(UserGroupModel), { through: UserGroupRelModel,foreignKey: "user_id" });
UserModel.belongsTo(OrganizationModel), { as: "PrimaryOrganization", foreignKey: "primary_organization_id" });
UserModel.belongsToMany(FooModel), { through: FooRelModel,foreignKey: "user_id" });
...
GET /user/?children=UserGroups|PrimaryOrganization

Finale API

initialize()

Set defaults and give finale a reference to your express app. Send the following parameters:

app
A reference to the Express application
base
Prefix to prepend to resource endpoints
updateMethod
HTTP method to use for update routes, one of POST, PUT, or PATCH

resource()

Create a resource and CRUD actions given a Sequelize model and endpoints. Accepts these parameters:

model
Reference to a Sequelize model
endpoints
Specify endpoints as an array with two sinatra-style URL paths in plural and singular form (e.g., ['/users', '/users/:id']).
actions
Create only the specified list of actions for the resource. Options include create, list, read, update, and delete. Defaults to all.
excludeAttributes
Explicitly remove the specified list of attributes from read and list operations

Milestones & Context

Check out the Milestone docs for information on lifecycle hooks that can be used with finale resources, and how to run custom code at various points during a request.

Protecting Finale REST Endpoints

To protect an endpoint, you must use milestones.

In order to protect and endpoint (for example, to require that only a logged in user or user with the appropriate security token can access a resource) you need to use the appropriate milestone hooks.

Below is an example of how to do this with standard Express middleware, which is commonly used to protect resources. Note that the callback functions required by Finale milestones look similar to express middleware, but the third argument (context) is different.

Suppose you have this resource:

var userResource = rest.resource({
    model: User
});

To protect all endpoints, we'll use userResource.all.auth, a hook used to authorize the endpoint before any operation (create, list, etc). Suppose also we have an express middlware function called authorize(req, res, done). This authorize function might for example be a passport strategy such as passport('local').

To authorize the endpoint, you would do this:

userResource.all.auth(function (req, res, context) {
  return new Promise(function(resolve, reject) {
    authorize(req, res, function (arg) {
      if (arg) {
        // Middleware function returned an error; this means the operation
        // should not be authorized.
        res.status(401).send({message: "Unauthorized"});
        resolve(context.stop);
      } else {
        resolve(context.continue);
      }
  });
})

In this code, note that userResource.all.auth is simply reusing the express middleware to do whatever authorization checking your code requires. We are passing a custom done function to the middleware, which resolves a promise as either context.stop or context.continue, indicating to finale whether or not to proceed. Note that in the case where the transaction isn't authorized, finale won't proceed, so it is your responsibility to send a response back to the client.

Protecting sub-resources

When models have assocations between them, to achieve the nested endpoints a la /user/1/UserGroups, finale creates sub-resources. Remember to set authorizations on those sub-resources as well. To get the sub-resources for a particular resource, you can use the string array subResourceNames attribute on the resource. Each name is also the name of an attribute on the resource.

userResource.all.auth(function (req, res, context) {
...
});

for(sub_resource_name in userResource.subResourceNames) {
    userResource[sub_resource_name].all.auth(function (req, res, context) {
      ...
    });
}

Further Information on Protecting Endpoints

The milestone documentation provides many other hooks for finer-grained operations, i.e. permitting all users to list but only some users to delete can be implemented by using the same approach described above, with different milestones.

Tests, Docker, OS X

The test suite requires use of Dtrace, which can be problematic on MacOS/OS X, which limits use of Dtrace. The base Dockerfile can be used to run tests.

docker build -t finale_test ./
docker run finale_test

Note: good errors happen, so stacktraces in the output are not necessarily indicative of a problem.

License

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.

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