api-pls

api-pls enables you to effortlessly create JSON API-compliant APIs.

Note: this project is a work in progress. It currently functions in a limited manner.

Motivation

It requires a lot of knowledge and time to put together a robust backend. api-pls is intended to speed up that process considerably.

Instead of writing boilerplate database and API code within your project, simply define models, and let this tool do the rest.

api-pls will:

✓ Configure a database for you
✓ Set up a web server that adheres to JSON API for interactions with those resources
✓ Create and run migrations for you when you change your resource models

This project is a work in progress. Resource migrations beyond the initial set up are currently unsupported.

Table of Contents

• Installation
• Getting Started
• CLI API
• Programmatic API
• JSON API Feature Support
• Technologies Used
• FAQ
• Acknowledgements
• Resource Model Definition ⇗
• Contributing Code ⇗
• Examples ⇗

Installation

Install api-pls into your project using npm.

npm install api-pls --save

This package comes with a programmatic interface as well as a command line tool.

Getting Started

api-pls is a system that reads configuration files that you write, called Resource Models, and uses those to run migrations on your database. It also has the ability to start an API based on your Resource Models.

The intent of api-pls is for you to replace database and API code in your web application with these declarative descriptions of resources.

For complete documentation on Resource Models, refer to the:

Resource Model documentation.

After your Resource Models are created, you are ready to start using api-pls.

Note: you technically don't need Resource Models to use any of the commands in api-pls, but nothing interesting happens unless you have at least one Resource Model.

CLI API

The name of the CLI program is pls. The rest of this guide assumes that pls is on your path. If you've installed it locally into a project, then you will need to call it from within an npm script.

Commands

Command	Description
reset-database	Removes all tables from the database
sync	Synchronize the DB with your Resource Models
start	Starts up the API webserver.

CLI Flags

All of the options may also be specified in .plsrc, if you would prefer. You may also specify the DATABASE_URL in a .env file in the directory that you call this command from.

Flags	Default	Description
-h, --help	N/A	View all the commands from the command line
-v, --version	N/A	Display the version of api-pls
-d, --database		Specify the database URL
-p, --port	5000	Configure the port of the webserver
-r, --resources	./resources	Set the directory of your resources
-s, --ssl	true	Whether or not to connect to the DB with SSL
-a, --api-version	1	The API version. It appears in the API URLs
-f, --force	N/A	Proceed with the action without confirmation
--silent	N/A	Disable logging
--verbose	N/A	Enable verbose logging

Example CLI Usage

The following example turns off SSL, sets the port to be 6000, and sets the resource directory.

pls start -p 6000 -s false -r ./my-resources

Programmatic API

The module exports a constructor, ApiPls.

ApiPls( options )

Returns an instance of ApiPls. Valid options are:

Option	Default	Description
resourcesDirectory	./resources	A string that is the location of your resource models.
databaseUrl		The URL of the database to connect to.
connectWithSsl	true	Whether or not to use SSL to connect to the database.
port	5000	The port to start the webserver on.
apiVersion	1	The version of the API. Appears in API URLs.
silent	false	Disables all logging from the web server when true.
verbose	false	Set to true to make the server to log more information.

apiPls.sync()

Synchronizes your data with the Resource Models in resourcesDirectory. Any data in dropped columns will be discarded.

To transform data in your database, such as moving it between columns or updating all of the data in a single column, see Migrations (coming soon!).

apiPls.start()

Starts the web server. Typically you'll want to run sync before doing this to make sure that the database is up-to-date.

apiPls.dangerouslyResetDatabase()

Removes all tables, and therefore, all of the data, from the database. This can be useful for testing. Be careful out there.

apiPls.apiRouter()

Returns an Express router that can be mounted to any Express server to host an api-pls API.

apiPls.db

An instance of the Database object from pg-promise.

Static Methods

These are methods that are attached to the ApiPls constructor. If you're writing libraries, plugins, or extensions to api-pls, then you might find these useful. Otherwise, you may never use them.

ApiPls.loadResourceModels( resourcesDirectory )

Loads all of the resource models from resourcesDirectory, which is a string that is the directory to load from.

ApiPls.normalizeModel( resourceModel )

Accepts a resourceModel, such as one returned from ApiPls.loadResourceModels(), and formats it into a normalized tree. If you're writing custom code to work with resource models, then this can make that easier for you.

ApiPls.validateResourceModel( resourceModel )

Accepts a resourceModel, and determines if it is valid or not. If you're writing custom logic around resource models, then this can be useful to catch errors in user-input resource models early on.

Example Programmatic Usage

import ApiPls from 'api-pls';
 
const apiPls = new ApiPls({
  DATABASE_URL: process.ENV.DATABASE_URL,
})
 
// Sync the database, then start the server.
apiPls.sync()
  .then(() => apiPls.start());

JSON API Feature Support

This project only partially supports JSON API. Features currently supported are:

• CRUD'ing resources
• Attributes
• Meta
• Consistent errors
• Sparse fieldsets
• Sorting
• Pagination
• Filtering
• Compound documents
• Links
• Relations
  • One-to-one
  • Many-to-one
  • Many-to-many
  • Relationship endpoints (/v1/:resource/relationships/:related)
  • Related endpoints (/v1/:resource/:id/:related)

Technologies Used

Currently, the only supported database is PostgreSQL. The webserver is written in Node.js using Express.

FAQ

Who is the target audience for api-pls?

It is my hope that engineers of all skill levels could find value in api-pls.

Engineers who may not feel confident in building a backend can use api-pls to get up-and-running quickly. They might even use api-pls as the entire backend for an application.

More confident engineers might find that api-pls is sufficient for some of the resources in an application they are building, so they may leverage it for those resources. And because api-pls tables can coexist with manually managed tables, there's no issue in only using api-pls for part of an application.

Acknowledgements

Tyler Kellen for his work on Endpoints (which inspired me to write this) and for our many conversations about REST.

Eric Valadas for helping plan the API and implementation of this library.