Class: TRMNLPreview::Context

Inherits:
Object
  • Object
show all
Defined in:
lib/trmnl_preview/context.rb

Defined Under Namespace

Classes: ERBBinding

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(root) ⇒ Context

Returns a new instance of Context.



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# File 'lib/trmnl_preview/context.rb', line 15

def initialize(root)
  config_path = File.join(root, 'config.toml')
  @user_views_dir = File.join(root, 'views')
  @temp_dir = File.join(root, 'tmp')
  @data_json_path = File.join(@temp_dir, 'data.json')

  @liquid_environment = Liquid::Environment.build do |env|
    env.register_filter(LiquidFilters)
  end

  unless File.exist?(config_path)
    raise "No config.toml found in #{root}"
  end

  unless Dir.exist?(@user_views_dir)
    raise "No views found at #{@user_views_dir}"
  end

  config = TomlRB.load_file(config_path)
  @strategy = config['strategy']
  @url = config['url']
  @polling_headers = config['polling_headers'] || {}
  @live_render = config['live_render'] != false

  unless ['polling', 'webhook'].include?(@strategy)
    raise "Invalid strategy: #{strategy} (must be 'polling' or 'webhook')"
  end

  FileUtils.mkdir_p(@temp_dir)

  start_filewatcher_thread if @live_render
end

Instance Attribute Details

#live_render ⇒ Object (readonly)

Returns the value of attribute live_render.



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# File 'lib/trmnl_preview/context.rb', line 13

def live_render
  @live_render
end

#strategy ⇒ Object (readonly)

Returns the value of attribute strategy.



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# File 'lib/trmnl_preview/context.rb', line 13

def strategy
  @strategy
end

#temp_dir ⇒ Object (readonly)

Returns the value of attribute temp_dir.



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# File 'lib/trmnl_preview/context.rb', line 13

def temp_dir
  @temp_dir
end

Instance Method Details

#on_view_change(&block) ⇒ Object 



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# File 'lib/trmnl_preview/context.rb', line 65

def on_view_change(&block)
  @view_change_callback = block
end

#poll_data ⇒ Object 



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# File 'lib/trmnl_preview/context.rb', line 75

def poll_data
  if @url.nil?
    raise "URL is required for polling strategy"
  end

  print "Fetching #{@url}... "

  if @url.match?(/^https?:\/\//)
    payload = URI.open(@url, @polling_headers).read
  else
    payload = File.read(@url)
  end

  File.write(@data_json_path, payload)
  puts "got #{payload.size} bytes"

  user_data
end

#render_full_page(view) ⇒ Object 



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# File 'lib/trmnl_preview/context.rb', line 114

def render_full_page(view)
  page_erb_template = File.read(File.join(__dir__, '..', '..', 'web', 'views', 'render_view.erb'))
  
  ERB.new(page_erb_template).result(ERBBinding.new(view).get_binding do
    render_template(view)
  end)
end

#render_template(view) ⇒ Object 



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# File 'lib/trmnl_preview/context.rb', line 102

def render_template(view)
    path = view_path(view)
    unless File.exist?(path)
      return "Missing plugin template: views/#{view}.liquid"
    end

    user_template = Liquid::Template.parse(File.read(path), environment: @liquid_environment)
    user_template.render(user_data)
rescue StandardError => e
  e.message
end

#set_data(payload) ⇒ Object 



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# File 'lib/trmnl_preview/context.rb', line 94

def set_data(payload)
  File.write(@data_json_path, payload)
end

#start_filewatcher_thread ⇒ Object 



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# File 'lib/trmnl_preview/context.rb', line 48

def start_filewatcher_thread
  Thread.new do
    loop do
      begin
        Filewatcher.new(@user_views_dir).watch do |changes|
          views = changes.map { |path, _change| File.basename(path, '.liquid') }
          views.each do |view|
            @view_change_callback.call(view) if @view_change_callback
          end
        end
      rescue => e
        puts "Error during live render: #{e}"
      end
    end
  end
end

#user_data ⇒ Object 



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# File 'lib/trmnl_preview/context.rb', line 69

def user_data
  data = JSON.parse(File.read(@data_json_path))
  data = { data: data } if data.is_a?(Array) # per TRMNL docs, bare array is wrapped in 'data' key
  data
end

#view_path(view) ⇒ Object 



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# File 'lib/trmnl_preview/context.rb', line 98

def view_path(view)
  File.join(@user_views_dir, "#{view}.liquid")
end