EditorjsRenderer is a Ruby gem that brings Editor.js support to Rails applications.
It allows rendering JSON data generated by Editor.js into safe HTML and plain text.

• Support for structured content (Editor.js blocks)
• Built-in validation using JSON Schema
• Secure HTML output via escaping
• Configurable block rendering system
• Support for nested blocks (blocks within blocks)
• Blocks: Spoiler, Table, Checklist, Attaches, Code, Delimiter, etc.
• No JavaScript dependencies required on the server side

Add this line to your Gemfile:

gem "editorjs_renderer"

And then execute:

bundle install

data = {
  "time" => "123456789",
  "blocks" => [
    { "type" => "paragraph", "data" => { "text" => "Hello <b>world</b>" } },
    { "type" => "checklist", "data" => { "items" => [
        { "text" => "Buy milk", "checked" => true },
        { "text" => "Read book", "checked" => false }
      ]}
    }
  ]
}

document = EditorjsRenderer::Document.new(data)
document.render(format: :html)
# => "<p>Hello &lt;b&gt;world&lt;/b&gt;</p><ul class=\"checklist-block\"><li><input type=\"checkbox\" checked disabled> Buy milk</li><li><input type=\"checkbox\" disabled> Read book</li></ul>"

document.render(format: :plain)
# => "Hello <b>world</b>\n[x] Buy milk\n[ ] Read book"

The gem includes a default schema for the paragraph block, located at:

lib/editorjs_renderer/schemas/

You can configure enabled block types and schema path:

EditorjsRenderer.configure do |config|
  config.enabled_blocks = %w[paragraph]
  config.schemas_path = Rails.root.join("config/editor_schemas").to_s
end

Schemas should follow the JSON Schema format and be stored in YAML files. Each block must have a schema named like paragraph.yml, header.yml, etc.

Example:

type: object
required:
  - text
properties:
  text:
  type: string
  description: "The main content of the header block"

In this schema:

• text is a required field of type string, which represents the header text.

To run tests and linters:

bundle exec rake

To support a new block:

1. Create a class in EditorjsRenderer::Blocks namespace (e.g., Header)
2. Inherit from EditorjsRenderer::Blocks::Base
3. Implement render and plain
4. Add a corresponding schema

module EditorjsRenderer
  module Blocks
    class Header < Base
      def render
        "<h1>#{ERB::Util.html_escape(data["text"])}</h1>"
      end

      def plain
        data["text"].to_s
      end
    end
  end
end

This gem uses Zeitwerk to handle autoloading. Ensure you have Zeitwerk set up in your environment:

require "zeitwerk"

loader = Zeitwerk::Loader.for_gem
loader.setup

Bug reports and pull requests are welcome on GitHub at https://github.com/lordsynergy/editorjs_renderer.

This gem is licensed under the MIT License.