Class: Rack::SpaRewrite

Inherits:
Object
  • Object
show all
Defined in:
lib/rack/spa_rewrite.rb

Overview

Intercept HTTP requests and serve index.html. This middleware caches the index_html file (or the bytes can be passed in). If the file contents change, new content is NOT served.

Constant Summary collapse

ALLOWED_VERBS = 
["GET", "HEAD", "OPTIONS"].freeze
ALLOW_HEADER = 
ALLOWED_VERBS.join(", ")

Instance Method Summary collapse

Constructor Details

#initialize(app, index_bytes:, html_only:) ⇒ SpaRewrite

Returns a new instance of SpaRewrite.

Parameters:

  • app —

    The Rack app.

  • index_bytes (String) —

    The index.html contents to serve.

  • html_only (true, false) —

    True to only intercept html requests, false to intercept all requests. Usually you want to setup SpaRewrite first using html:false, then html:true as the final Rack app/middleware.



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# File 'lib/rack/spa_rewrite.rb', line 18

def initialize(app, index_bytes:, html_only:)
  @app = app
  @index_bytes = index_bytes
  @html_only = html_only
  @head = Rack::Head.new(->(env) { get env })
  @started_at = Time.now.httpdate
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/rack/spa_rewrite.rb', line 26

def call(env)
  # HEAD requests drop the response body, including 4xx error messages.
  @head.call env
end

#get(env) ⇒ Object 



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# File 'lib/rack/spa_rewrite.rb', line 31

def get(env)
  request = Rack::Request.new env
  return @app.call(env) if @html_only && !request.path_info.end_with?(".html")
  return [405, {"Allow" => ALLOW_HEADER}, ["Method Not Allowed"]] unless
    ALLOWED_VERBS.include?(request.request_method)

  path_info = Rack::Utils.unescape_path(request.path_info)
  return [400, {}, ["Bad Request"]] unless Rack::Utils.valid_path?(path_info)

  return [200, {"Allow" => ALLOW_HEADER, Rack::CONTENT_LENGTH => "0"}, []] if
    request.options?

  return [304, {}, []] if request.get_header("HTTP_IF_MODIFIED_SINCE") == @started_at

  headers = {
    "content-length" => @index_bytes.bytesize.to_s,
    "content-type" => "text/html",
    "last-modified" => @started_at,
  }
  return [200, headers, [@index_bytes]]
end