Module: Turbo::StreamsHelper

Defined in:
app/helpers/turbo/streams_helper.rb

Instance Method Summary collapse

Instance Method Details

#turbo_stream ⇒ Object

Returns a new Turbo::Streams::TagBuilder object that accepts stream actions and renders them as the template tags needed to send across the wire. This object is automatically yielded to turbo_stream.erb templates.

When responding to HTTP requests, controllers can declare turbo_stream format response templates in that same style as html and json response formats. For example, consider a MessagesController that responds to both text/html and text/vnd.turbo-stream.html requests along with a .turbo_stream.erb action template:

def create
  @message = Message.create!(params.require(:message).permit(:content))
  respond_to do |format|
    format.turbo_stream
    format.html { redirect_to messages_url }
  end
end

<%# app/views/messages/create.turbo_stream.erb %>
<%= turbo_stream.append "messages", @message %>

<%= turbo_stream.replace "new_message" do %>
  <%= render partial: "new_message", locals: { room: @room } %>
<% end %>

When a app/views/messages/create.turbo_stream.erb template exists, the ‘MessagesController#create` will respond to text/vnd.turbo-stream.html requests by rendering the messages/create.turbo_stream.erb view template and transmitting the response



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# File 'app/helpers/turbo/streams_helper.rb', line 27

def turbo_stream
  Turbo::Streams::TagBuilder.new(self)
end

#turbo_stream_from(*streamables, **attributes) ⇒ Object

Used in the view to create a subscription to a stream identified by the streamables running over the Turbo::StreamsChannel. The stream name being generated is safe to embed in the HTML sent to a user without fear of tampering, as it is signed using Turbo.signed_stream_verifier. Example:

# app/views/entries/index.html.erb
<%= turbo_stream_from Current.account, :entries %>
<div id="entries">New entries will be appended to this target</div>

The example above will process all turbo streams sent to a stream name like account:5:entries (when Current.account.id = 5). Updates to this stream can be sent like entry.broadcast_append_to entry.account, :entries, target: "entries".

Custom channel class name can be passed using :channel option (either as a String or a class name):

<%= turbo_stream_from "room", channel: RoomChannel %>

It is also possible to pass additional parameters to the channel by passing them through data attributes:

<%= turbo_stream_from "room", channel: RoomChannel, data: {room_name: "room #1"} %>

Raises an ArgumentError if all streamables are blank

<%= turbo_stream_from("") %> # => ArgumentError: streamables can't be blank
<%= turbo_stream_from("", nil) %> # => ArgumentError: streamables can't be blank

Raises:

  • (ArgumentError) 


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# File 'app/helpers/turbo/streams_helper.rb', line 56

def turbo_stream_from(*streamables, **attributes)
  raise ArgumentError, "streamables can't be blank" unless streamables.any?(&:present?)
  attributes[:channel] = attributes[:channel]&.to_s || "Turbo::StreamsChannel"
  attributes[:"signed-stream-name"] = Turbo::StreamsChannel.signed_stream_name(streamables)

  tag.turbo_cable_stream_source(**attributes)
end