Configuring CORS headers

Please be sure of your agent type and version and pick the right documentation accordingly.

Node.js

This is the documentation of the forest-express-sequelize and forest-express-mongoose Node.js agents that will soon reach end-of-support.

forest-express-sequelize v9 and forest-express-mongoose v9 are replaced by @forestadmin/agent v1.

Please check your agent type and version and read on or switch to the right documentation.

Ruby on Rails

This is still the latest Ruby on Rails documentation of the forest_liana agent, you’re at the right place, please read on.

Python

This is the documentation of the django-forestadmin Django agent that will soon reach end-of-support.

If you’re using a Django agent, notice that django-forestadmin v1 is replaced by forestadmin-agent-django v1.

If you’re using a Flask agent, go to the forestadmin-agent-flask v1 documentation.

Please check your agent type and version and read on or switch to the right documentation.

PHP

This is the documentation of the forestadmin/laravel-forestadmin Laravel agent that will soon reach end-of-support.

If you’re using a Laravel agent, notice that forestadmin/laravel-forestadmin v1 is replaced by forestadmin/laravel-forestadmin v3.

If you’re using a Symfony agent, go to the forestadmin/symfony-forestadmin v1 documentation.

Please check your agent type and version and read on or switch to the right documentation.

Configuring CORS headers

Depending on how you've setup your app, you may encounter a CORS error. It will look like this in your browser console:

In this case, you need to configure the right CORS headers to allow the domain app.forestadmin.com to trigger an API call on your Application URL, which is a different domain name (e.g. localhost:3000 on development).

Rails

We use the Rack CORS Gem for this purpose.

gemfile

# Gemfile
source 'https://rubygems.org'

# ...

gem 'forest_liana'
gem 'rack-cors'

config/application.rb

module YourApp
  class Application < Rails::Application
    # ...

    # For Rails 5, use the class Rack::Cors. For Rails 4, you MUST use the string 'Rack::Cors'.
    null_regex = Regexp.new(/\Anull\z/)
    config.middleware.insert_before 0, Rack::Cors do
      allow do
        hostnames = [null_regex, 'localhost:4200', 'app.forestadmin.com', 'localhost:3001']
        hostnames += ENV['CORS_ORIGINS'].split(',') if ENV['CORS_ORIGINS']
        origins hostnames
        resource '*',
          headers: :any,
          methods: :any,
          expose: ['Content-Disposition'],
          credentials: true
      end
    end
  end
end