Class: Socket2me::Middleware::AddScriptTag

Inherits:
Object
  • Object
show all
Defined in:
lib/socket2me/middleware/add_script_tag.rb

Instance Method Summary collapse

Constructor Details

#initialize(app) ⇒ AddScriptTag

Returns a new instance of AddScriptTag.



9
10
11
12
 
# File 'lib/socket2me/middleware/add_script_tag.rb', line 9

def initialize(app)
  @app = app
  @ws_url = "ws://#{Socket2me.config.ws_host}:#{Socket2me.config.ws_port}"
end

Instance Method Details

#call(env) ⇒ String, ...

  1. look for a text/html response type from parent app.

  2. replace the closing ‘</body>` with the WebSocket client code.

Parameters:

  • env (Hash) —

    about Rack environment and the request

Returns:

  • (String, Hash, Array[String]) 


19
20
21
22
23
24
25
26
27
28
29
30
31
 
# File 'lib/socket2me/middleware/add_script_tag.rb', line 19

def call(env)
  response = @app.call(env)
  status, headers, body = *response

  return response unless headers['Content-Type'] == 'text/html'

  full_body = body.join

  # replace the last body with script
  full_body.gsub!(%r{(</body>)}i,"#{script_tag}\\1")

  return status, headers, [full_body]
end

#js_erb ⇒ String

Adjust the javascript client code as needed.

Returns:

  • (String) —

    inner javascript contents.



41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
 
# File 'lib/socket2me/middleware/add_script_tag.rb', line 41

def js_erb
  "(function () {\n    var socket = new WebSocket(\"<%= @ws_url %>\");\n\n    function log(message) {\n  console.log.apply(console, arguments);\n    }\n\n    try {\n  socket.onopen = function () {\n      log(\"Socket Status: \" + socket.readyState + \" (open)\");\n  };\n\n  socket.onclose = function () {\n      log(\"Socket Status: \" + socket.readyState + \" (closed)\");\n  };\n\n  socket.onmessage = function (msg) {\n      try {\n          // execute in an anonymous function\n          new Function(msg.data)();\n      } catch (msgEx){\n          console.error(\"Could not execute `%s` due to %o\", msg.data, msgEx);\n      }\n  }\n    } catch (exception) {\n  console.error(\"Error: \" + exception);\n    }\n})();\n  JS\nend\n"

#script_tag ⇒ String

Returns the outer Javascript tag with WS client script.

Returns:

  • (String) —

    the outer Javascript tag with WS client script



34
35
36
37
 
# File 'lib/socket2me/middleware/add_script_tag.rb', line 34

def script_tag
  js = ERB.new(js_erb).result(binding)
  "<script>#{js}</script>"
end