Alchemy::JsonApi

A JSON-API based API for AlchemyCMS

Installation

In your Alchemy Rails project

Add this line to your application's Gemfile:

gem 'alchemy-json_api'

And then execute:

$ bundle

Or install it yourself as:

$ gem install alchemy-json_api

In your JS/Frontend app

Run this in your application:

npm install @alchemy_cms/json_api --save

or with the package manager of your choice

Usage

In your Rails app

Mount the engine in your Alchemy Rails app like this:

# config/routes.rb
mount Alchemy::JsonApi::Engine => "/jsonapi/"

NOTE Pick any path you like. This will be the prefix of your API URLs

In your frontend app

This repo provides an NPM package with deserializers to help you convert the response into JS objects.

import { deserializePages } from "@alchemy_cms/json_api"

const response = await fetch("/jsonapi/pages.json")
const data = await response.json()
const pages = deserializePages(data)

console.log(pages[0].name) // => Homepage

HTTP Caching

Alchemy::JsonApi allows for caching API responses. It respects the caching configuration of your Rails app and of your Alchemy configuration and settings in the pages page layout configuration. Restricted pages are never cached.

By default it sets the max-age Cache-Control header to 10 minutes (600 seconds). You can change this by configuring the Alchemy::JsonApi.page_cache_max_age setting. It is recommended to set this via an environment variable like this:

# config/initializers/alchemy_json_api.rb
Alchemy::JsonApi.page_cache_max_age = ENV.fetch("ALCHEMY_JSON_API_CACHE_DURATION", 600).to_i

Edge Caching

Alchemy sets the must-revalidate directive if caching is enabled. If your CDN supports it, you can change that to use the much more efficient stale-while-revalidate directive by changing the Alchemy::JsonApi.page_caching_options setting to any integer value.

# config/initializers/alchemy_json_api.rb
Alchemy::JsonApi.page_caching_options = {
  stale_while_revalidate: ENV.fetch("ALCHEMY_JSON_API_CACHE_STALE_WHILE_REVALIDATE", 60).to_i
}

Tip

You can set any caching option that ActionController::ConditionalGet#expires_in supports, like stale_if_error, public or immutable.

Key transforms

If you ever want to change how Alchemy serializes attributes you can set

# config/initializers/alchemy_json_api.rb
Alchemy::JsonApi.key_transform = :camel_lower

It defaults to :underscore.

Contributing

Contribution directions go here.

License

The gem is available as open source under the terms of the BSD-3-Clause license.