libs/httpd/luasrc/httpd/module.lua

   1 --[[
   2 LuCI - Lua Configuration Interface
   3
   4 Copyright 2008 Steven Barth <steven@midlink.org>
   5
   6 Licensed under the Apache License, Version 2.0 (the "License");
   7 you may not use this file except in compliance with the License.
   8 You may obtain a copy of the License at
   9
  10         http://www.apache.org/licenses/LICENSE-2.0
  11
  12 $Id$
  13 ]]--
  14 module("luci.httpd.module", package.seeall)
  15 require("luci.util")
  16 require("luci.http.protocol")
  17 require("ltn12")
  18
  19
  20
  21 -- Server handler implementation
  22 Handler = luci.util.class()
  23
  24 -- Constructor
  25 function Handler.__init__(self)
  26         self.filters = {}
  27 end
  28
  29
  30 -- Adds a filter to the filter chain
  31 function Handler.addfilter(self, filter)
  32         table.insert(self.filters, filter)
  33 end
  34
  35
  36 -- Creates a failure reply
  37 function Handler.failure(self, code, message)
  38         local response = Response(code, { ["Content-Type"] = "text/plain" })
  39         local sourceout = ltn12.source.string(message)
  40
  41         return response, sourceout
  42 end
  43
  44
  45 -- Processes a request
  46 function Handler.process(self, request, sourcein, sinkout, sinkerr)
  47         -- Process incoming filters
  48         for i, f in ipairs(self.filters) do
  49                 local i = f:get("input")
  50
  51                 if i then
  52                         sourcein = ltn12.source.chain(sourcein, i)
  53                 end
  54
  55                 if f.request then
  56                         f:request(request)
  57                 end
  58         end
  59
  60         -- Run the handler
  61         local stat, response, sourceout = luci.util.copcall(
  62                 self.handle, self, request, sourcein, sinkerr
  63         )
  64
  65         -- Check for any errors
  66         if not stat then
  67                 response, sourceout = self:failure(500, response)
  68         end
  69
  70         -- Check data
  71         if not luci.util.instanceof(response, Response) then
  72                 response, sourceout = self:failure(500, "Core error: Invalid module response!")
  73         end
  74
  75         -- Process outgoing filters
  76         for i, f in ipairs(self.filters) do
  77                 local o = f:get("output")
  78
  79                 if o then
  80                         sourceout = ltn12.source.chain(sourceout, o)
  81                 end
  82
  83                 if f.response then
  84                         f:response(response)
  85                 end
  86         end
  87
  88         luci.http.protocol.push_response(request, response, sourceout, sinkout, sinkerr)
  89 end
  90
  91
  92
  93 -- Server Filter implementation
  94 Filter = luci.util.class()
  95
  96 function Filter.get(self, name)
  97         return self[name] and function(...) return self[name](self, ...) end
  98 end
  99
 100 -- Filters the incoming body stream
 101 -- abstract function Filter.input(chunk)
 102
 103 -- Filters the outgoing body stream
 104 -- abstract function Filter.output(chunk)
 105
 106 -- Filters the request object
 107 -- abstract function Filter.request(request)
 108
 109 -- Filters the response object
 110 -- abstract function Filter.response(response)
 111
 112
 113
 114 -- Handler Response
 115 Response = luci.util.class()
 116
 117 function Response.__init__(self, status, headers)
 118         self.status = tonumber(status) or 200
 119         self.headers = (type(headers) == "table") and headers or {}
 120 end
 121
 122 function Response.addheader(self, key, value)
 123         self.headers[key] = value
 124 end
 125
 126 function Response.setstatus(self, status)
 127         self.status = status
 128 end