Class: WrapItRuby::Middleware::ScriptInjectionMiddleware

Inherits:
Object
  • Object
show all
Defined in:
lib/wrap_it_ruby/middleware/script_injection_middleware.rb

Overview

Injects interception.js inline into HTML responses from the proxy.

  • Strips Accept-Encoding from proxy requests so upstream sends uncompressed HTML (avoids decompress/recompress just to inject).

  • Buffers HTML responses and injects the script as the first child of <head>.

  • Extracts the proxy host from PATH_INFO and injects it as window.__proxyHost so the script works even when the browser URL doesn’t contain /_proxy/ (e.g. after root-relative navigation).

  • Injects window.__hostingSite so the interception script knows which host is the proxy server itself.

  • Reads the script file once and caches it.

Constant Summary collapse

PROXY_PREFIX = 
"/_proxy/"
SCRIPT_FILE = 
File.expand_path("../../../app/assets/javascripts/wrap_it_ruby/interception.js", __dir__).freeze

Instance Method Summary collapse

Constructor Details

#initialize(app) ⇒ ScriptInjectionMiddleware

Returns a new instance of ScriptInjectionMiddleware.



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# File 'lib/wrap_it_ruby/middleware/script_injection_middleware.rb', line 22

def initialize(app)
  @app = app
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/wrap_it_ruby/middleware/script_injection_middleware.rb', line 26

def call(env)
  path = env["PATH_INFO"].to_s

  if path.start_with?(PROXY_PREFIX)
    host = path.delete_prefix(PROXY_PREFIX).split("/", 2).first
    hosting_site = env["HTTP_HOST"]

    env.delete("HTTP_ACCEPT_ENCODING")
    status, headers, body = @app.call(env)

    if html_response?(headers)
      body = inject_script(body, headers, host, hosting_site)
    end

    [status, headers, body]
  else
    @app.call(env)
  end
end