Module: ReactOnRails::Helper

Includes:
Pro::Helper, Utils::Required, ScoutApm::Tracer
Included in:
ReactOnRailsHelper
Defined in:
lib/react_on_rails/helper.rb

Constant Summary collapse

COMPONENT_HTML_KEY = 
"componentHtml"

Constants included from Pro::Helper

Pro::Helper::IMMEDIATE_HYDRATION_PRO_WARNING

Instance Method Summary collapse

Methods included from Pro::Helper

#disabled_pro_features_message, #generate_component_script, #generate_store_script, #pro_warning_badge_if_needed

Methods included from Utils::Required

#required

Instance Method Details

#build_react_component_result_for_server_rendered_hash(server_rendered_html: required("server_rendered_html"), component_specification_tag: required("component_specification_tag"), console_script: required("console_script"), render_options: required("render_options")) ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 573

def build_react_component_result_for_server_rendered_hash(
  server_rendered_html: required("server_rendered_html"),
  component_specification_tag: required("component_specification_tag"),
  console_script: required("console_script"),
  render_options: required("render_options")
)
  content_tag_options = render_options.html_options
  content_tag_options[:id] = render_options.dom_id

  unless server_rendered_html[COMPONENT_HTML_KEY]
    raise ReactOnRails::Error, "server_rendered_html hash expected to contain \"#{COMPONENT_HTML_KEY}\" key."
  end

  rendered_output = content_tag(:div,
                                server_rendered_html[COMPONENT_HTML_KEY].html_safe,
                                content_tag_options)

  result_console_script = render_options.replay_console ? console_script : ""
  result = compose_react_component_html_with_spec_and_console(
    component_specification_tag, rendered_output, result_console_script
  )

  # Other HTML strings need to be marked as html_safe too:
  server_rendered_hash_except_component = server_rendered_html.except(COMPONENT_HTML_KEY)
  server_rendered_hash_except_component.each do |key, html_string|
    server_rendered_hash_except_component[key] = html_string.html_safe
  end

  result_with_rails_context = prepend_render_rails_context(result)
  { COMPONENT_HTML_KEY => result_with_rails_context }.merge(
    server_rendered_hash_except_component
  )
end

#build_react_component_result_for_server_rendered_string(server_rendered_html: required("server_rendered_html"), component_specification_tag: required("component_specification_tag"), console_script: required("console_script"), render_options: required("render_options")) ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 520

def build_react_component_result_for_server_rendered_string(
  server_rendered_html: required("server_rendered_html"),
  component_specification_tag: required("component_specification_tag"),
  console_script: required("console_script"),
  render_options: required("render_options")
)
  content_tag_options = render_options.html_options
  if content_tag_options.key?(:tag)
    content_tag_options_html_tag = content_tag_options[:tag]
    content_tag_options.delete(:tag)
  else
    content_tag_options_html_tag = "div"
  end
  content_tag_options[:id] = render_options.dom_id

  rendered_output = content_tag(content_tag_options_html_tag.to_sym,
                                server_rendered_html.html_safe,
                                content_tag_options)

  result_console_script = render_options.replay_console ? console_script : ""
  result = compose_react_component_html_with_spec_and_console(
    component_specification_tag, rendered_output, result_console_script
  )

  prepend_render_rails_context(result)
end

#build_react_component_result_for_server_streamed_content(rendered_html_stream:, component_specification_tag:, render_options:) ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 547

def build_react_component_result_for_server_streamed_content(
  rendered_html_stream:,
  component_specification_tag:,
  render_options:
)
  is_first_chunk = true
  rendered_html_stream.transform do |chunk_json_result|
    if is_first_chunk
      is_first_chunk = false
      build_react_component_result_for_server_rendered_string(
        server_rendered_html: chunk_json_result["html"],
        component_specification_tag: component_specification_tag,
        console_script: chunk_json_result["consoleReplayScript"],
        render_options: render_options
      )
    else
      result_console_script = render_options.replay_console ? chunk_json_result["consoleReplayScript"] : ""
      # No need to prepend component_specification_tag or add rails context again
      # as they're already included in the first chunk
      compose_react_component_html_with_spec_and_console(
        "", chunk_json_result["html"], result_console_script
      )
    end
  end
end

#compose_react_component_html_with_spec_and_console(component_specification_tag, rendered_output, console_script) ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 607

def compose_react_component_html_with_spec_and_console(component_specification_tag, rendered_output,
                                                       console_script)
  # IMPORTANT: Ensure that we mark string as html_safe to avoid escaping.
  added_html = "#{component_specification_tag}\n#{console_script}".strip
  added_html = added_html.present? ? "\n#{added_html}" : ""

  "#{rendered_output}#{added_html}".html_safe
end

#create_render_options(react_component_name, options) ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 487

def create_render_options(react_component_name, options)
  # If no store dependencies are passed, default to all registered stores up till now
  unless options.key?(:store_dependencies)
    store_dependencies = registered_stores_including_deferred.map { |store| store[:store_name] }
    options = options.merge(store_dependencies: store_dependencies.presence)
  end
  ReactOnRails::ReactComponent::RenderOptions.new(react_component_name: react_component_name,
                                                  options: options)
end

#generated_components_pack_path(component_name) ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 516

def generated_components_pack_path(component_name)
  "#{ReactOnRails::PackerUtils.packer_source_entry_path}/generated/#{component_name}.js"
end

#in_mailer? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/react_on_rails/helper.rb', line 782

def in_mailer?
  return false unless defined?(controller)
  return false unless defined?(ActionMailer::Base)

  controller.is_a?(ActionMailer::Base)
end

#initialize_redux_stores(render_options) ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 752

def initialize_redux_stores(render_options)
  result = +<<-JS
  ReactOnRails.clearHydratedStores();
  JS

  store_dependencies = render_options.store_dependencies
  return result unless store_dependencies.present?

  declarations = +"var reduxProps, store, storeGenerator;\n"
  store_objects = registered_stores_including_deferred.select do |store|
    store_dependencies.include?(store[:store_name])
  end

  result << store_objects.each_with_object(declarations) do |redux_store_data, memo|
    store_name = redux_store_data[:store_name]
    props = props_string(redux_store_data[:props])
    memo << <<-JS.strip_heredoc
    reduxProps = #{props};
    storeGenerator = ReactOnRails.getStoreGenerator('#{store_name}');
    store = storeGenerator(reduxProps, railsContext);
    ReactOnRails.setStore('#{store_name}', store);
    JS
  end
  result
end

#internal_react_component(react_component_name, options = {}) ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 636

def internal_react_component(react_component_name, options = {})
  # Create the JavaScript and HTML to allow either client or server rendering of the
  # react_component.
  #
  # Create the JavaScript setup of the global to initialize the client rendering
  # (re-hydrate the data). This enables react rendered on the client to see that the
  # server has already rendered the HTML.

  render_options = create_render_options(react_component_name, options)

  # Setup the page_loaded_js, which is the same regardless of prerendering or not!
  # The reason is that React is smart about not doing extra work if the server rendering did its job.
  component_specification_tag = generate_component_script(render_options)

  load_pack_for_generated_component(react_component_name, render_options)
  # Create the HTML rendering part
  result = server_rendered_react_component(render_options)

  {
    render_options: render_options,
    tag: component_specification_tag,
    result: result
  }
end

#internal_rsc_payload_react_component(react_component_name, options = {}) ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 507

def internal_rsc_payload_react_component(react_component_name, options = {})
  options = options.merge(render_mode: :rsc_payload_streaming)
  render_options = create_render_options(react_component_name, options)
  json_stream = server_rendered_react_component(render_options)
  json_stream.transform do |chunk|
    "#{chunk.to_json}\n".html_safe
  end
end

#internal_stream_react_component(component_name, options = {}) ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 497

def internal_stream_react_component(component_name, options = {})
  options = options.merge(render_mode: :html_streaming)
  result = internal_react_component(component_name, options)
  build_react_component_result_for_server_streamed_content(
    rendered_html_stream: result[:result],
    component_specification_tag: result[:tag],
    render_options: result[:render_options]
  )
end

#json_safe_and_pretty(hash_or_string) ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 350

def json_safe_and_pretty(hash_or_string)
  return "{}" if hash_or_string.nil?

  unless hash_or_string.is_a?(String) || hash_or_string.is_a?(Hash)
    raise ReactOnRails::Error, "#{__method__} only accepts String or Hash as argument " \
                               "(#{hash_or_string.class} given)."
  end

  json_value = hash_or_string.is_a?(String) ? hash_or_string : hash_or_string.to_json

  ReactOnRails::JsonOutput.escape(json_value)
end

#load_pack_for_generated_component(react_component_name, render_options) ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 429

def load_pack_for_generated_component(react_component_name, render_options)
  return unless render_options.auto_load_bundle

  ReactOnRails::PackerUtils.raise_nested_entries_disabled unless ReactOnRails::PackerUtils.nested_entries?
  if Rails.env.development?
    is_component_pack_present = File.exist?(generated_components_pack_path(react_component_name))
    raise_missing_autoloaded_bundle(react_component_name) unless is_component_pack_present
  end

  options = { defer: ReactOnRails.configuration.generated_component_packs_loading_strategy == :defer }
  # Old versions of Shakapacker don't support async script tags.
  # ReactOnRails.configure already validates if async loading is supported by the installed Shakapacker version.
  # Therefore, we only need to pass the async option if the loading strategy is explicitly set to :async
  options[:async] = true if ReactOnRails.configuration.generated_component_packs_loading_strategy == :async
  append_javascript_pack_tag("generated/#{react_component_name}", **options)
  append_stylesheet_pack_tag("generated/#{react_component_name}")
end

#prepend_render_rails_context(render_value) ⇒ Object

prepend the rails_context if not yet applied



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# File 'lib/react_on_rails/helper.rb', line 630

def prepend_render_rails_context(render_value)
  rails_context_content = rails_context_if_not_already_rendered
  rails_context_content = rails_context_content.present? ? "#{rails_context_content}\n" : ""
  "#{rails_context_content}#{render_value}".html_safe
end

#props_string(props) ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 667

def props_string(props)
  props.is_a?(String) ? props : props.to_json
end

#rails_context(server_side: true) ⇒ Object

This is the definitive list of the default values used for the rails_context, which is the second parameter passed to both component and store Render-Functions. This method can be called from views and from the controller, as ‘helpers.rails_context`

rubocop:disable Metrics/AbcSize, Metrics/CyclomaticComplexity



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# File 'lib/react_on_rails/helper.rb', line 368

def rails_context(server_side: true)
  # ALERT: Keep in sync with node_package/src/types/index.ts for the properties of RailsContext
  @rails_context ||= begin
    result = {
      componentRegistryTimeout: ReactOnRails.configuration.component_registry_timeout,
      railsEnv: Rails.env,
      inMailer: in_mailer?,
      # Locale settings
      i18nLocale: I18n.locale,
      i18nDefaultLocale: I18n.default_locale,
      rorVersion: ReactOnRails::VERSION,
      # TODO: v13 just use the version if existing
      rorPro: ReactOnRails::Utils.react_on_rails_pro?
    }

    if ReactOnRails::Utils.react_on_rails_pro?
      result[:rorProVersion] = ReactOnRails::Utils.react_on_rails_pro_version

      if ReactOnRails::Utils.rsc_support_enabled?
        rsc_payload_url = ReactOnRailsPro.configuration.rsc_payload_generation_url_path
        result[:rscPayloadGenerationUrlPath] = rsc_payload_url
      end
    end

    if defined?(request) && request.present?
      # Check for encoding of the request's original_url and try to force-encoding the
      # URLs as UTF-8. This situation can occur in browsers that do not encode the
      # entire URL as UTF-8 already, mostly on the Windows platform (IE11 and lower).
      original_url_normalized = request.original_url
      if original_url_normalized.encoding == Encoding::BINARY
        original_url_normalized = original_url_normalized.force_encoding(Encoding::ISO_8859_1)
                                                         .encode(Encoding::UTF_8)
      end

      # Using Addressable instead of standard URI to better deal with
      # non-ASCII characters (see https://github.com/shakacode/react_on_rails/pull/405)
      uri = Addressable::URI.parse(original_url_normalized)
      # uri = Addressable::URI.parse("http://foo.com:3000/posts?id=30&limit=5#time=1305298413")

      result.merge!(
        # URL settings
        href: uri.to_s,
        location: "#{uri.path}#{"?#{uri.query}" if uri.query.present?}",
        scheme: uri.scheme, # http
        host: uri.host, # foo.com
        port: uri.port,
        pathname: uri.path, # /posts
        search: uri.query, # id=30&limit=5
        httpAcceptLanguage: request.env["HTTP_ACCEPT_LANGUAGE"]
      )
    end
    if ReactOnRails.configuration.rendering_extension
      custom_context = ReactOnRails.configuration.rendering_extension.custom_context(self)
      result.merge!(custom_context) if custom_context
    end
    result
  end

  @rails_context.merge(serverSide: server_side)
end

#rails_context_if_not_already_rendered ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 616

def rails_context_if_not_already_rendered
  return "" if @rendered_rails_context

  data = rails_context(server_side: false)

  @rendered_rails_context = true

  content_tag(:script,
              json_safe_and_pretty(data).html_safe,
              type: "application/json",
              id: "js-react-on-rails-context")
end

#raise_missing_autoloaded_bundle(react_component_name) ⇒ Object

Raises:



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# File 'lib/react_on_rails/helper.rb', line 796

def raise_missing_autoloaded_bundle(react_component_name)
  msg = <<~MSG
    **ERROR** ReactOnRails: Component "#{react_component_name}" is configured as "auto_load_bundle: true"
    but the generated component entrypoint, which should have been at #{generated_components_pack_path(react_component_name)},
    is missing. You might want to check that this component is in a directory named "#{ReactOnRails.configuration.components_subdirectory}"
    & that "bundle exec rake react_on_rails:generate_packs" has been run.
  MSG

  raise ReactOnRails::Error, msg
end

#raise_prerender_error(json_result, react_component_name, props, js_code) ⇒ Object

Raises:



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# File 'lib/react_on_rails/helper.rb', line 671

def raise_prerender_error(json_result, react_component_name, props, js_code)
  raise ReactOnRails::PrerenderError.new(
    component_name: react_component_name,
    props: sanitized_props_string(props),
    err: nil,
    js_code: js_code,
    console_messages: json_result["consoleReplayScript"]
  )
end

#react_component(component_name, options = {}) ⇒ Object

react_component_name: can be a React function or class component or a “Render-Function”. “Render-Functions” differ from a React function in that they take two parameters, the

props and the railsContext, like this:

let MyReactComponentApp = (props, railsContext) => <MyReactComponent {...props}/>;

Alternately, you can define the Render-Function with an additional property
`.renderFunction = true`:

let MyReactComponentApp = (props) => <MyReactComponent {...props}/>;
MyReactComponent.renderFunction = true;

Exposing the react_component_name is necessary to both a plain ReactComponent as well as
  a generator:
See README.md for how to "register" your React components.
See spec/dummy/client/app/packs/server-bundle.js and
  spec/dummy/client/app/packs/client-bundle.js for examples of this.

options:

props: Ruby Hash or JSON string which contains the properties to pass to the react object. Do
   not pass any props if you are separately initializing the store by the `redux_store` helper.
prerender: <true/false> set to false when debugging!
id: You can optionally set the id, or else a unique one is automatically generated.
html_options: You can set other html attributes that will go on this component
trace: <true/false> set to true to print additional debugging information in the browser
       default is true for development, off otherwise
replay_console: <true/false> Default is true. False will disable echoing server rendering
                logs to browser. While this can make troubleshooting server rendering difficult,
                so long as you have the default configuration of logging_on_server set to
                true, you'll still see the errors on the server.
raise_on_prerender_error: <true/false> Default to false. True will raise exception on server
   if the JS code throws

Any other options are passed to the content tag, including the id. random_dom_id can be set to override the default from the config/initializers. That’s only used if you have multiple instance of the same component on the Rails view.



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# File 'lib/react_on_rails/helper.rb', line 58

def react_component(component_name, options = {})
  internal_result = internal_react_component(component_name, options)
  server_rendered_html = internal_result[:result]["html"]
  console_script = internal_result[:result]["consoleReplayScript"]
  render_options = internal_result[:render_options]

  case server_rendered_html
  when String
    html = build_react_component_result_for_server_rendered_string(
      server_rendered_html: server_rendered_html,
      component_specification_tag: internal_result[:tag],
      console_script: console_script,
      render_options: render_options
    )
    html.html_safe
  when Hash
    msg = <<~MSG
      Use react_component_hash (not react_component) to return a Hash to your ruby view code. See
      https://github.com/shakacode/react_on_rails/blob/master/spec/dummy/client/app/startup/ReactHelmetServerApp.jsx
      for an example of the necessary javascript configuration.
    MSG
    raise ReactOnRails::Error, msg
  else
    class_name = server_rendered_html.class.name
    msg = <<~MSG
      ReactOnRails: server_rendered_html is expected to be a String or Hash for #{component_name}.
      Type is #{class_name}
      Value:
      #{server_rendered_html}

      If you're trying to use a Render-Function to return a Hash to your ruby view code, then use
      react_component_hash instead of react_component and see
      https://github.com/shakacode/react_on_rails/blob/master/spec/dummy/client/app/startup/ReactHelmetServerApp.jsx
      for an example of the JavaScript code.
    MSG
    raise ReactOnRails::Error, msg
  end
end

#react_component_hash(component_name, options = {}) ⇒ Object

react_component_hash is used to return multiple HTML strings for server rendering, such as for adding meta-tags to a page. It is exactly like react_component except for the following:

  1. prerender: true is automatically added, as this method doesn’t make sense for client only rendering.

  2. Your JavaScript Render-Function for server rendering must return an Object rather than a React component.

  3. Your view code must expect an object and not a string.

Here is an example of the view code:

<% react_helmet_app = react_component_hash("ReactHelmetApp", prerender: true,
                                           props: { helloWorldData: { name: "Mr. Server Side Rendering"}},
                                           id: "react-helmet-0", trace: true) %>
<% content_for :title do %>
  <%= react_helmet_app['title'] %>
<% end %>
<%= react_helmet_app["componentHtml"] %>



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# File 'lib/react_on_rails/helper.rb', line 212

def react_component_hash(component_name, options = {})
  options[:prerender] = true

  internal_result = internal_react_component(component_name, options)
  server_rendered_html = internal_result[:result]["html"]
  console_script = internal_result[:result]["consoleReplayScript"]
  render_options = internal_result[:render_options]

  if server_rendered_html.is_a?(String) && internal_result[:result]["hasErrors"]
    server_rendered_html = { COMPONENT_HTML_KEY => internal_result[:result]["html"] }
  end

  if server_rendered_html.is_a?(Hash)
    build_react_component_result_for_server_rendered_hash(
      server_rendered_html: server_rendered_html,
      component_specification_tag: internal_result[:tag],
      console_script: console_script,
      render_options: render_options
    )

  else
    msg = <<~MSG
      Render-Function used by react_component_hash for #{component_name} is expected to return
      an Object. See https://github.com/shakacode/react_on_rails/blob/master/spec/dummy/client/app/startup/ReactHelmetServerApp.jsx
      for an example of the JavaScript code.
      Note, your Render-Function must either take 2 params or have the property
      `.renderFunction = true` added to it to distinguish it from a React Function Component.
    MSG
    raise ReactOnRails::Error, msg
  end
end

#redux_store(store_name, props: {}, defer: false, immediate_hydration: nil) ⇒ Object

Separate initialization of store from react_component allows multiple react_component calls to use the same Redux store.

NOTE: This technique not recommended as it prevents dynamic code splitting for performance. Instead, you should use the standard react_component view helper.

store_name: name of the store, corresponding to your call to ReactOnRails.registerStores in your

JavaScript code.

props: Ruby Hash or JSON string which contains the properties to pass to the redux store. Options

defer: false -- pass as true if you wish to render this below your component.
immediate_hydration: false -- React on Rails Pro (licensed) feature. Pass as true if you wish to
                    hydrate this store immediately instead of waiting for the page to load.



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# File 'lib/react_on_rails/helper.rb', line 257

def redux_store(store_name, props: {}, defer: false, immediate_hydration: nil)
  immediate_hydration = ReactOnRails.configuration.immediate_hydration if immediate_hydration.nil?

  redux_store_data = { store_name: store_name,
                       props: props,
                       immediate_hydration: immediate_hydration }
  if defer
    registered_stores_defer_render << redux_store_data
    "YOU SHOULD NOT SEE THIS ON YOUR VIEW -- Uses as a code block, like <% redux_store %> " \
      "and not <%= redux store %>"
  else
    registered_stores << redux_store_data
    result = render_redux_store_data(redux_store_data)
    prepend_render_rails_context(result).html_safe
  end
end

#redux_store_hydration_data ⇒ Object

Place this view helper (no parameters) at the end of your shared layout. This tell ReactOnRails where to client render the redux store hydration data. Since we’re going to be setting up the stores in the controllers, we need to know where on the view to put the client side rendering of this hydration data, which is a hidden div with a matching class that contains a data props.



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# File 'lib/react_on_rails/helper.rb', line 279

def redux_store_hydration_data
  return if registered_stores_defer_render.blank?

  registered_stores_defer_render.reduce(+"") do |accum, redux_store_data|
    accum << render_redux_store_data(redux_store_data)
  end.html_safe
end

#registered_stores ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 475

def registered_stores
  @registered_stores ||= []
end

#registered_stores_defer_render ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 479

def registered_stores_defer_render
  @registered_stores_defer_render ||= []
end

#registered_stores_including_deferred ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 483

def registered_stores_including_deferred
  registered_stores + registered_stores_defer_render
end

#render_redux_store_data(redux_store_data) ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 661

def render_redux_store_data(redux_store_data)
  store_hydration_data = generate_store_script(redux_store_data)

  prepend_render_rails_context(store_hydration_data)
end

#replay_console_option(val) ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 778

def replay_console_option(val)
  val.nil? ? ReactOnRails.configuration.replay_console : val
end

#rsc_payload_react_component(component_name, options = {}) ⇒ String

Note:

This helper requires React Server Components support to be enabled in your configuration: ReactOnRailsPro.configure do |config|

config.enable_rsc_support = true

end

Note:

You don’t have to deal directly with this helper function - it’s used internally by the

Renders the React Server Component (RSC) payload for a given component. This helper generates a special format designed by React for serializing server components and transmitting them to the client.

Example NDJSON stream:

{"html":"<RSC Payload>","consoleReplayScript":"","hasErrors":false,"isShellReady":true}
{"html":"<RSC Payload>","consoleReplayScript":"console.log('Loading...')","hasErrors":false,"isShellReady":true}

The RSC payload within the html field contains:

  • The component’s rendered output from the server

  • References to client components that need hydration

  • Data props passed to client components

‘rsc_payload_route` helper function. The returned data from this function is used internally by components registered using the `registerServerComponent` function. Don’t use it unless you need more control over the RSC payload generation. To know more about RSC payload, see the following link:

Examples:

Basic usage with a server component

<%= rsc_payload_react_component("ReactServerComponentPage") %>

With props and tracing enabled

<%= rsc_payload_react_component("RSCPostsPage",
      props: { artificialDelay: 1000 },
      trace: true) %>

Parameters:

  • component_name (String) —

    The name of the React component to render. This component should be a server component or a mixed component tree containing both server and client components.

  • options (Hash) (defaults to: {}) —

    Options for rendering the component

Options Hash (options):

  • :props (Hash) —

    Props to pass to the component (default: {})

  • :trace (Boolean) —

    Enable tracing for debugging (default: false)

  • :id (String) —

    Custom DOM ID for the component container (optional)

Returns:

  • (String) —

    Returns a Newline Delimited JSON (NDJSON) stream where each line contains a JSON object with:

    • html: The RSC payload containing the rendered server components and client component references

    • consoleReplayScript: JavaScript to replay server-side console logs in the client

    • hasErrors: Boolean indicating if any errors occurred during rendering

    • isShellReady: Boolean indicating if the initial shell is ready for hydration

Raises:

  • (ReactOnRailsPro::Error) —

    if RSC support is not enabled in configuration

See Also:



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# File 'lib/react_on_rails/helper.rb', line 186

def rsc_payload_react_component(component_name, options = {})
  # rsc_payload_react_component doesn't have the prerender option
  # Because setting prerender to false will not do anything
  options[:prerender] = true
  run_stream_inside_fiber do
    internal_rsc_payload_react_component(component_name, options)
  end
end

#run_stream_inside_fiber ⇒ Object

rubocop:enable Metrics/AbcSize, Metrics/CyclomaticComplexity



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# File 'lib/react_on_rails/helper.rb', line 449

def run_stream_inside_fiber
  unless ReactOnRails::Utils.react_on_rails_pro?
    raise ReactOnRails::Error,
          "You must use React on Rails Pro to use the stream_react_component method."
  end

  if @rorp_rendering_fibers.nil?
    raise ReactOnRails::Error,
          "You must call stream_view_containing_react_components to render the view containing the react component"
  end

  rendering_fiber = Fiber.new do
    stream = yield
    stream.each_chunk do |chunk|
      Fiber.yield chunk
    end
  end

  @rorp_rendering_fibers << rendering_fiber

  # return the first chunk of the fiber
  # It contains the initial html of the component
  # all updates will be appended to the stream sent to browser
  rendering_fiber.resume
end

#sanitized_props_string(props) ⇒ Object 



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# File 'lib/react_on_rails/helper.rb', line 287

def sanitized_props_string(props)
  ReactOnRails::JsonOutput.escape(props.is_a?(String) ? props : props.to_json)
end

#server_render_js(js_expression, options = {}) ⇒ Object

Helper method to take javascript expression and returns the output from evaluating it. If you have more than one line that needs to be executed, wrap it in an IIFE. JS exceptions are caught and console messages are handled properly. Options include:{ prerender:, trace:, raise_on_prerender_error:, throw_js_errors: }



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# File 'lib/react_on_rails/helper.rb', line 295

def server_render_js(js_expression, options = {})
  render_options = ReactOnRails::ReactComponent::RenderOptions
                   .new(react_component_name: "generic-js", options: options)

  js_code = <<-JS.strip_heredoc
  (function() {
    var htmlResult = '';
    var consoleReplayScript = '';
    var hasErrors = false;
    var renderingError = null;
    var renderingErrorObject = {};

    try {
      htmlResult =
        (function() {
          return #{js_expression};
        })();
    } catch(e) {
      renderingError = e;
      if (#{render_options.throw_js_errors}) {
        throw e;
      }
      htmlResult = ReactOnRails.handleError({e: e, name: null,
        jsCode: '#{escape_javascript(js_expression)}', serverSide: true});
      hasErrors = true;
      renderingErrorObject = {
        message: renderingError.message,
        stack: renderingError.stack,
      }
    }

    consoleReplayScript = ReactOnRails.buildConsoleReplay();

    return JSON.stringify({
        html: htmlResult,
        consoleReplayScript: consoleReplayScript,
        hasErrors: hasErrors,
        renderingError: renderingErrorObject
    });

  })()
  JS

  result = ReactOnRails::ServerRenderingPool
           .server_render_js_with_console_logging(js_code, render_options)

  html = result["html"]
  console_log_script = result["consoleLogScript"]
  raw("#{html}#{console_log_script if render_options.replay_console}")
rescue ExecJS::ProgramError => err
  raise ReactOnRails::PrerenderError.new(component_name: "N/A (server_render_js called)",
                                         err: err,
                                         js_code: js_code)
end

#server_rendered_react_component(render_options) ⇒ Object

Returns object with values that are NOT html_safe!



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# File 'lib/react_on_rails/helper.rb', line 691

def server_rendered_react_component(render_options)
  return { "html" => "", "consoleReplayScript" => "" } unless render_options.prerender

  react_component_name = render_options.react_component_name
  props = render_options.props

  # On server `location` option is added (`location = request.fullpath`)
  # React Router needs this to match the current route

  # Make sure that we use up-to-date bundle file used for server rendering, which is defined
  # by config file value for config.server_bundle_js_file
  ReactOnRails::ServerRenderingPool.reset_pool_if_server_bundle_was_modified

  # Since this code is not inserted on a web page, we don't need to escape props
  #
  # However, as JSON (returned from `props_string(props)`) isn't JavaScript,
  # but we want treat it as such, we need to compensate for the difference.
  #
  # \u2028 and \u2029 are valid characters in strings in JSON, but are treated
  # as newline separators in JavaScript. As no newlines are allowed in
  # strings in JavaScript, this causes an exception.
  #
  # We fix this by replacing these unicode characters with their escaped versions.
  # This should be safe, as the only place they can appear is in strings anyway.
  #
  # Read more here: http://timelessrepo.com/json-isnt-a-javascript-subset

  js_code = ReactOnRails::ServerRenderingJsCode.server_rendering_component_js_code(
    props_string: props_string(props).gsub("\u2028", '\u2028').gsub("\u2029", '\u2029'),
    rails_context: rails_context(server_side: true).to_json,
    redux_stores: initialize_redux_stores(render_options),
    react_component_name: react_component_name,
    render_options: render_options
  )

  begin
    result = ReactOnRails::ServerRenderingPool.server_render_js_with_console_logging(js_code, render_options)
  rescue StandardError => err
    # This error came from the renderer
    raise ReactOnRails::PrerenderError.new(component_name: react_component_name,
                                           # Sanitize as this might be browser logged
                                           props: sanitized_props_string(props),
                                           err: err,
                                           js_code: js_code)
  end

  if render_options.streaming?
    result.transform do |chunk_json_result|
      if should_raise_streaming_prerender_error?(chunk_json_result, render_options)
        raise_prerender_error(chunk_json_result, react_component_name, props, js_code)
      end
      # It doesn't make any transformation, it listens and raises error if a chunk has errors
      chunk_json_result
    end
  elsif result["hasErrors"] && render_options.raise_on_prerender_error
    raise_prerender_error(result, react_component_name, props, js_code)
  end

  result
end

#should_raise_streaming_prerender_error?(chunk_json_result, render_options) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/react_on_rails/helper.rb', line 681

def should_raise_streaming_prerender_error?(chunk_json_result, render_options)
  chunk_json_result["hasErrors"] &&
    (if chunk_json_result["isShellReady"]
       render_options.raise_non_shell_server_rendering_errors
     else
       render_options.raise_on_prerender_error
     end)
end

#stream_react_component(component_name, options = {}) ⇒ Object

Streams a server-side rendered React component using React’s ‘renderToPipeableStream`. Supports React 18 features like Suspense, concurrent rendering, and selective hydration. Enables progressive rendering and improved performance for large components.

Note: This function can only be used with React on Rails Pro. The view that uses this function must be rendered using the ‘stream_view_containing_react_components` method from the React on Rails Pro gem.

Example of an async React component that can benefit from streaming:

const AsyncComponent = async () => 

const data = await fetchData();
return <div>{data</div>;

};

function App() {

return (
  <Suspense fallback={<div>Loading...</div>}>
    <AsyncComponent />
  </Suspense>
);

}

Any other options are passed to the content tag, including the id.

Parameters:

  • component_name (String) —

    Name of your registered component

  • options (Hash) (defaults to: {}) —

    Options for rendering

Options Hash (options):

  • :props (Hash) —

    Props to pass to the react component

  • :dom_id (String) —

    DOM ID of the component container

  • :html_options (Hash) —

    Options passed to content_tag

  • :trace (Boolean) —

    Set to true to add extra debugging information to the HTML

  • :raise_on_prerender_error (Boolean) —

    Set to true to raise exceptions during server-side rendering



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# File 'lib/react_on_rails/helper.rb', line 128

def stream_react_component(component_name, options = {})
  # stream_react_component doesn't have the prerender option
  # Because setting prerender to false is equivalent to calling react_component with prerender: false
  options[:prerender] = true
  options = options.merge(immediate_hydration: true) unless options.key?(:immediate_hydration)
  run_stream_inside_fiber do
    internal_stream_react_component(component_name, options)
  end
end