plugins/mod_http_errors.lua

   1 module:set_global();
   2
   3 local server = require "net.http.server";
   4 local codes = require "net.http.codes";
   5 local xml_escape = require "util.stanza".xml_escape;
   6 local render = require "util.interpolation".new("%b{}", xml_escape);
   7
   8 local show_private = module:get_option_boolean("http_errors_detailed", false);
   9 local always_serve = module:get_option_boolean("http_errors_always_show", true);
  10 local default_message = { module:get_option_string("http_errors_default_message", "That's all I know.") };
  11 local default_messages = {
  12         [400] = { "What kind of request do you call that??" };
  13         [403] = { "You're not allowed to do that." };
  14         [404] = { "Whatever you were looking for is not here. %";
  15                 "Where did you put it?", "It's behind you.", "Keep looking." };
  16         [500] = { "% Check your error log for more info.";
  17                 "Gremlins.", "It broke.", "Don't look at me." };
  18 };
  19
  20 local messages = setmetatable(module:get_option("http_errors_messages", {}), { __index = default_messages });
  21
  22 local html = [[
  23 <!DOCTYPE html>
  24 <html>
  25 <head>
  26 <meta charset="utf-8">
  27 <title>{title}</title>
  28 <style>
  29 body{
  30         margin-top:14%;
  31         text-align:center;
  32         background-color:#F8F8F8;
  33         font-family:sans-serif;
  34 }
  35 h1{
  36         font-size:xx-large;
  37 }
  38 p{
  39         font-size:x-large;
  40 }
  41 p+p {
  42         font-size:large;
  43         font-family:courier;
  44 }
  45 </style>
  46 </head>
  47 <body>
  48 <h1>{title}</h1>
  49 <p>{message}</p>
  50 <p>{extra?}</p>
  51 </body>
  52 </html>
  53 ]];
  54
  55 local function get_page(code, extra)
  56         local message = messages[code];
  57         if always_serve or message then
  58                 message = message or default_message;
  59                 return render(html, {
  60                         title = rawget(codes, code) or ("Code "..tostring(code));
  61                         message = message[1]:gsub("%%", function ()
  62                                 return message[math.random(2, math.max(#message,2))];
  63                         end);
  64                         extra = extra;
  65                 });
  66         end
  67 end
  68
  69 module:hook_object_event(server, "http-error", function (event)
  70         if event.response then
  71                 event.response.headers.content_type = "text/html; charset=utf-8";
  72         end
  73         return get_page(event.code, (show_private and event.private_message) or event.message);
  74 end);