Module: LiveCable::Component::Rendering

Extended by:
ActiveSupport::Concern
Included in:
LiveCable::Component
Defined in:
lib/live_cable/component/rendering.rb

Instance Method Summary collapse

Instance Method Details

#render ⇒ Object 



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# File 'lib/live_cable/component/rendering.rb', line 18

def render
  @rendered = true
  ApplicationController.renderer.render(self, layout: false)
end

#render_in(view_context) ⇒ Object 



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# File 'lib/live_cable/component/rendering.rb', line 40

def render_in(view_context)
  view, render_context = view_context.with_render_context(self) do
    result = view_context.render(template: to_partial_path, locals:)

    unless result.is_a?(LiveCable::Rendering::Partial)
      warn(
        "[LiveCable Warning] #{to_partial_path} was rendered without using a .live.erb template, " \
        'this will be less performant.'
      )

      next result
    end

    # Track which template we're rendering
    current_template_path = to_partial_path

    # Initialize static_sent hash and track previous template
    @static_sent ||= {}
    @previous_template_path ||= nil

    # Detect template change - if template changed, force dynamic render
    template_changed = previous_template_path && previous_template_path != current_template_path

    # Determine if we should send diffs or full render
    changes = if static_sent[current_template_path]
                # Static already sent for this template
                template_changed ? :dynamic : live_connection&.changeset_for(self)
              else
                :all
              end

    @previous_template_path = current_template_path

    result.for_component(self, view_context).render_changes(changes)
  end

  unless (partial = view.is_a?(Array))
    view = [view]
  end

  # If we are rendering the initial page, we only need to add the attributes to most parent element
  # as it will re-render again anyway when the socket is available. On this render when the live connection
  # is available, the components can be stored properly, so when each of their sockets connects, it won't need
  # to render them again. This prevents multiple re-renders of children when the parent renders, then renders
  # again, and then the child socket connects and renders that again as well.
  if (render_context.root? || live_connection) && !view[0].nil?
    view[0] = insert_root_attributes(view[0], view_context)
  end

  if previous_render_context
    # Children from skipped parts are preserved — their part simply didn't
    # re-evaluate this cycle, so they haven't actually gone away.
    preserved = render_context.preserved_children_from(previous_render_context)
    destroyed = previous_render_context.children - render_context.children - preserved
    destroyed.each(&:destroy)
  end

  # We didn't get a LiveCable Partial, so just return it with one part
  unless partial
    if live_connection && render_context.root?
      return LiveCable::Rendering::RenderResult.new(live_id, view, to_partial_path)
    else
      return view[0]
    end
  end

  if live_connection
    @static_sent[previous_template_path] = true

    @previous_render_context = render_context
    result = LiveCable::Rendering::RenderResult.new(live_id, view, to_partial_path)

    if render_context.root?
      result.child_results = render_context.render_results

      return result
    else
      # Always use LiveCable placeholder for non-root children
      # This allows JavaScript to store the component before subscription connects
      render_context << result

      return "<LiveCable child-live-id=\"#{live_id}\"></LiveCable>".html_safe
    end
  end

  view_context.safe_join(view)
end

#rendered_children ⇒ Array<LiveCable::Component>

Returns:



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# File 'lib/live_cable/component/rendering.rb', line 129

def rendered_children
  previous_render_context&.children || []
end

#to_partial_path ⇒ Object 



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# File 'lib/live_cable/component/rendering.rb', line 23

def to_partial_path
  base = self.class.name.underscore

  if self.class.is_compound
    state = variant
    raise LiveCable::Error, "#{self.class.name}#variant must return a non-nil value" if state.nil?

    "#{base}/#{state}"
  else
    base
  end
end

#variant ⇒ Object 



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# File 'lib/live_cable/component/rendering.rb', line 36

def variant
  'component'
end