Cable Component API

The cable component enables us to update the DOM based on events and data pushed via ActionCable without a browser reload.

Please read the ActionCable Guide if you need help setting up ActionCable for your project, and make sure you have set up ActionCable correctly. The following code snippet is crucial to make the cable component work correctly:

app/javascript/channels/matestack_ui_core_channel.js

import MatestackUiCore form 'matestack-ui-core';

consumer.subscriptions.create("MatestackUiCoreChannel", {
  //...
  received(data) {
    MatestackUiCore.eventHub.$emit(data.event, data)
  }
});

A cable component renders a Vue.js driven cable component initially containing content specified by a block.

Imagine something like this:

class Page < Matestack::Ui::Page

  def response
    cable id: 'foo' [...] do
      # this block will be rendered as initial content and may be
      # modified on the client side later upon receiving defined events
      DummyModel.all.each do |instance|
        ListComponent.(item: instance)
      end
    end
  end
end

class ListComponent < Matestack::Ui::Component

  required :item

  def response
    # make sure to define an unique ID on the root element of your component
    # the declared ID may be used later on to update or delete this component on the client side
    div id: "item-#{context.item.id}", class: "row" do
      #...
    end
  end

end

Please note: When rendering a list of items, we recommend to use a custom component for each item. This makes it easy to render unique items on the server side and push them via ActionCable to the client. Technically, it is also possible to use another component or a simple html string. Any given html will be used to update the item.

Parameters

id - required

Expects an unique string that identifies the cable component

append_on

Expects a string that matches the event which will be emitted via ActionCable on the serverside. Event payload data in form of HTML will be appended to the current cable component DOM.

In your app, page or component:

cable id: 'foo', append_on: "model_created" do
  DummyModel.all.each do |instance|
    ListComponent.(item: instance)
  end
end

In your controller:

ActionCable.server.broadcast("matestack_ui_core", {
  event: "model_created",
  data: ListComponent.(item: @new_model_instance)
})

data can also be an array of components.

prepend_on

Expects a string that matches the event which will be emitted via ActionCable on the serverside. Event payload data in form of HTML will be prepended to the current cable component DOM.

In your app, page or component:

cable id: 'foo', prepend_on: "model_created" do
  DummyModel.all.each do |instance|
    ListComponent.(item: instance)
  end
end

In your controller:

ActionCable.server.broadcast("matestack_ui_core", {
  event: "model_created",
  data: ListComponent.(item: @new_model_instance)
})

data can also be an array of components.

replace_on

Expects a string that matches the event which will be emitted via ActionCable on the serverside. Event payload data in form of HTML will replace the whole current cable component DOM.

In your app, page or component:

cable id: 'foo', replace_on: "model_created" do
  DummyModel.all.each do |instance|
    ListComponent.(item: instance)
  end
end

In your controller:

ActionCable.server.broadcast("matestack_ui_core", {
  event: "model_created",
  data: ListComponent.(item: @new_model_instance)
})

data can also be an array of components.

update_on

Expects a string that matches the event which will be emitted via ActionCable on the serverside. Event payload data in form of HTML will update a specific element iditified by its root ID within the current cable component DOM.

In your app, page or component:

cable id: 'foo', append_on: "model_created" do
  DummyModel.all.each do |instance|
    ListComponent.(item: instance)
  end
end

In your controller:

ActionCable.server.broadcast("matestack_ui_core", {
  event: "model_created",
  data: matestack_component(:list_component, item: @new_model_instance)
})

data can also be an array of components.

delete_on

Expects a string that matches the event which will be emitted via ActionCable on the serverside. Event payload data in form of a string containing the ID will remove a specific element identified by its root ID within the current cable component DOM.

In your app, page or component:

cable id: 'foo', delete_on: "model_deleted" do
  DummyModel.all.each do |instance|
    ListComponent.(item: instance)
  end
end

In your controller:

ActionCable.server.broadcast("matestack_ui_core", {
  event: "model_deleted",
  data: "item-#{params[:id]}"
})

data can also be an Array of ID-strings.