LINE Message Builder

Build LINE messages using DSL (Domain Specific Language) in Ruby.

Features

• Build LINE messages using DSL
• Validation of properties
• RSpec matchers for testing
• LINE Bot SDK v2 support (Experimental)

Installation

Install the gem and add to the application's Gemfile by executing:

bundle add line-message-builder

If bundler is not being used to manage dependencies, install the gem by executing:

gem install line-message-builder

Usage

[!NOTE] Working in progress.

LLM.txt

The llm.txt is available in document assets.

You can get it from http://aotoki.me/line-message-builder/llm.txt.

Builder

builder = Line::Message::Builder.with do
  text "Hello, world!"
end

pp builder.build
# => [{ type: "text", text: "Hello, world!" }]

puts builder.to_json
# => "[{\"type\":\"text\",\"text\":\"Hello, world!\"}]"

To use with line-bot-sdk-ruby v2, you can set mode to sdkv2:

builder = Line::Message::Builder.with(mode: :sdkv2) do
  text "Hello, world!"
end

Context

The context can make Builder to access additional methods and variables.

context = OpenStruct.new(
  name: "John Doe",
)

builder = Line::Message::Builder.with(context) do
  text "Hello, #{name}!"
end

pp builder.build
# => [{ type: "text", text: "Hello, John Doe!" }]

puts builder.to_json
# => "[{\"type\":\"text\",\"text\":\"Hello, John Doe!\"}]"

For Rails, you can use view_context to make Builder to access Rails helpers.

# app/controllers/line_controller.rb
builder = Line::Message::Builder.with(view_context) do
  text "Anything you want?" do
    quick_reply do
      message "Yes", label: "Yes", image_url: image_url("yes.png")
      message "No", label: "No", image_url: image_url("no.png")
    end
  end
end

If not in controller, you can create a ActionView::Base instance and pass it to Builder.

# app/presenters/line_presenter.rb
context = ActionView::Base.new(
  ActionController::Base.view_paths,
  {},
  ActionController::Base.new,
)

builder = Line::Message::Builder.with(context) do
  text "Anything you want?" do
    quick_reply do
      message "Yes", label: "Yes", image_url: image_url("yes.png")
      message "No", label: "No", image_url: image_url("no.png")
    end
  end
end

Partial

[!WARNING] This is experimental and may change in the future.

You can create a partial object to reuse the same structure in the Carousel, Bubble, or Box.

# Reuse the bubble structure in the Carousel
class CardPartial < Line::Message::Builder::Flex::Partial
  def call
    body do
      text "Hello World!"
    end
  end
end

builder = Line::Message::Builder.with do
  carousel do
    3.times do |i|
      bubble do
        partial! CardPartial
      end
    end
  end
end

The partial can have assigns feature to provide variables to the partial.

class CardPartial < Line::Message::Builder::Flex::Partial
  def call
    body do
      text "Card #{idx}!"
    end
  end
end

builder = Line::Message::Builder.with do
  carousel do
    3.times do |i|
      bubble do
        partial! CardPartial, idx: i
      end
    end
  end
end

[!NOTE] The assigns will override the context variables.

RSpec Matcher

Matcher	Description
have_line_text_message	Match a text message
have_line_flex_message	Match a flex message
have_line_flex_bubble	Match a flex message with bubble
have_line_flex_text	Match a flex message with text
have_line_flex_image	Match a flex message with image
have_line_flex_button	Match a flex message with button
have_line_flex_box	Match a flex message with box
have_line_flex_separator	Match a flex message with separator
have_line_flex_icon	Match a flex message with icon

Add line/message/rspec to your spec_helper.rb or rails_helper.rb:

require "line/message/rspec"

Include Line::Message::RSpec::Matchers in your RSpec configuration:

RSpec.configure do |config|
  config.include Line::Message::RSpec::Matchers
end

Then the matchers are available in your specs:

let(:builder) do
  Line::Message::Builder.with do
    text "Hello, world!"
    text "Nice to meet you!"
  end
end

subject { builder.build }

it { is_expected.to have_line_text_message("Hello, world!") }
it { is_expected.to have_line_text_message(/Nice to meet you!/) }

The matchers can work with webmock a_request:

it "reply with message" do
  expect(a_request(:post, "https://api.line.me/v2/bot/message/reply")
    .with(
      body: hash_including({
        messages: have_line_text_message(/Hello, world!/),
      })
    )
  ).to have_been_made.once
end

Capabilities

• ✅ Supported
• 🚧 Partially Supported
• ❌ Not Supported

Message Types

Type	Supported
Text	🚧
Text v2	❌
Sticker	❌
Sticker	❌
Image	❌
Video	❌
Audio	❌
Location	❌
Imagemap	❌
Template	❌
Flex	🚧

Common Properties

Property	Supported
Quick Reply	✅
Sender	❌

Actions

Action Type	Supported
Postback	🚧
Message	✅
Uri	✅
Datetime	❌
Camera	❌
CameraRoll	❌
Location	❌
Richmenu Switch	❌
Clipboard	❌

Flex Components

Component	Supported
Bubble	🚧
Carousel	✅
Box	✅
Button	✅
Image	✅
Video	❌
Icon	🚧
Text	🚧
Span	🚧
Separator	✅
Filler	❌ Deprecated

Text, Span and Icon are marked partial only because their size option accepts the none–xxl keywords and pixel values, while LINE also defines xxs and 3xl–5xl. Every other property of these components is supported.

Bubble is missing direction and a bubble-level action. Postback is missing inputOption and fillInText.

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/elct9620/line-message-builder.

License

The gem is available as open source under the terms of the MIT License.