Module: Pgbus::Streams::Renderer

Defined in:
lib/pgbus/streams/renderer.rb

Overview

Turns a renderable into a complete ‘<turbo-stream>` action tag, ready to hand to Stream#broadcast. This centralises the off-request render + tag-building that every consumer would otherwise stitch together by hand (the #1 footgun in server-driven UI: rendering a component outside a request without a usable view context).

pgbus deliberately has no hard dependency on turbo-rails, ActionView, or Phlex, so this builder is self-contained and matches Turbo’s wire format directly. The browser’s Turbo runtime consumes the tag; the exact string is the contract, not any particular Ruby library.

Renderable resolution (first match wins):

- String              → used verbatim (already-rendered markup)
- responds to :call   → Phlex::HTML#call (the issue's example shape)
- responds to :render_in → ViewComponent / phlex-rails
  (`render_in(view_context)`; a nil context is passed because
  off-request there is no controller — components that need URL
  helpers should be rendered by the app and the string passed in)
- else                → to_s

Tag format mirrors Turbo::Streams::TagBuilder:

- content actions wrap the markup in a <template>
- content-less actions (remove) emit no <template>

Constant Summary collapse

CONTENTLESS_ACTIONS =

Turbo stream actions that carry no content (no <template> wrapper).

%w[remove].freeze

Class Method Summary collapse

Class Method Details

.escape(value) ⇒ Object 



62
63
64
 
# File 'lib/pgbus/streams/renderer.rb', line 62

def escape(value)
  CGI.escape_html(value.to_s)
end

.render(renderable) ⇒ Object

Resolves a renderable to an HTML string. See module docs for the resolution order. Returns “” for nil (a content action with no renderable still emits an empty <template>).



53
54
55
56
57
58
59
60
 
# File 'lib/pgbus/streams/renderer.rb', line 53

def render(renderable)
  return "" if renderable.nil?
  return renderable if renderable.is_a?(String)
  return renderable.call.to_s if renderable.respond_to?(:call)
  return renderable.render_in(nil).to_s if renderable.respond_to?(:render_in)

  renderable.to_s
end

.turbo_stream_tag(action:, target:, renderable: nil) ⇒ Object

Builds a ‘<turbo-stream action target><template>…</template></turbo-stream>` string. `renderable` may be nil for content-less actions.

Raises:

  • (ArgumentError) 


38
39
40
41
42
43
44
45
46
47
48
 
# File 'lib/pgbus/streams/renderer.rb', line 38

def turbo_stream_tag(action:, target:, renderable: nil)
  raise ArgumentError, "target is required" if target.nil? || target.to_s.empty?

  action = action.to_s
  attrs = %(action="#{escape(action)}" target="#{escape(target)}")

  return "<turbo-stream #{attrs}></turbo-stream>" if CONTENTLESS_ACTIONS.include?(action)

  content = render(renderable)
  "<turbo-stream #{attrs}><template>#{content}</template></turbo-stream>"
end