libs/web: add luci.http.write_json()

diff --git a/libs/web/luasrc/http.lua b/libs/web/luasrc/http.lua
index d34e253a53a8c9a550304270633b59e3770e81e0..85854054840f5078ed71199f21e930e94f5be893 100644 (file)
--- a/libs/web/luasrc/http.lua
+++ b/libs/web/luasrc/http.lua
@@ -12,9 +12,9 @@ Copyright 2008 Steven Barth <steven@midlink.org>
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
-You may obtain a copy of the License at 
+You may obtain a copy of the License at
 
-       http://www.apache.org/licenses/LICENSE-2.0 
+       http://www.apache.org/licenses/LICENSE-2.0
 
 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
@@ -29,8 +29,10 @@ local protocol = require "luci.http.protocol"
 local util  = require "luci.util"
 local string = require "string"
 local coroutine = require "coroutine"
+local table = require "table"
 
-local pairs, tostring, error = pairs, tostring, error
+local ipairs, pairs, next, type, tostring, error =
+       ipairs, pairs, next, type, tostring, error
 
 --- LuCI Web Framework high-level HTTP functions.
 module "luci.http"
@@ -45,14 +47,14 @@ function Request.__init__(self, env, sourcein, sinkerr)
 
        -- File handler
        self.filehandler = function() end
-       
+
        -- HTTP-Message table
        self.message = {
                env = env,
                headers = {},
                params = protocol.urldecode_params(env.QUERY_STRING or ""),
        }
-       
+
        self.parsed_input = false
 end
 
@@ -60,7 +62,7 @@ function Request.formvalue(self, name, noparse)
        if not noparse and not self.parsed_input then
                self:_parse_input()
        end
-       
+
        if name then
                return self.message.params[name]
        else
@@ -71,18 +73,18 @@ end
 function Request.formvaluetable(self, prefix)
        local vals = {}
        prefix = prefix and prefix .. "." or "."
-       
+
        if not self.parsed_input then
                self:_parse_input()
        end
-       
+
        local void = self.message.params[nil]
        for k, v in pairs(self.message.params) do
                if k:find(prefix, 1, true) == 1 then
                        vals[k:sub(#prefix + 1)] = tostring(v)
                end
        end
-       
+
        return vals
 end
 
@@ -90,7 +92,7 @@ function Request.content(self)
        if not self.parsed_input then
                self:_parse_input()
        end
-       
+
        return self.message.content, self.message.content_length
 end
 
@@ -128,7 +130,7 @@ function close()
                context.eoh = true
                coroutine.yield(3)
        end
-       
+
        if not context.closed then
                context.closed = true
                coroutine.yield(5)
@@ -164,7 +166,7 @@ function getcookie(name)
        return context.request:getcookie(name)
 end
 
---- Get the value of a certain HTTP environment variable 
+--- Get the value of a certain HTTP environment variable
 -- or the environment table itself.
 -- @param name         Environment variable
 -- @return                     HTTP environment value or environment table
@@ -248,8 +250,8 @@ function write(content, src_err)
                                header("Cache-Control", "no-cache")
                                header("Expires", "0")
                        end
-                       
-                       
+
+
                        context.eoh = true
                        coroutine.yield(3)
                end
@@ -276,14 +278,18 @@ end
 --- Create a querystring out of a table of key - value pairs.
 -- @param table                Query string source table
 -- @return                     Encoded HTTP query string
-function build_querystring(table)
-       local s="?"
-       
-       for k, v in pairs(table) do
-               s = s .. urlencode(k) .. "=" .. urlencode(v) .. "&"
+function build_querystring(q)
+       local s = { "?" }
+
+       for k, v in pairs(q) do
+               if #s > 1 then s[#s+1] = "&" end
+
+               s[#s+1] = urldecode(k)
+               s[#s+1] = "="
+               s[#s+1] = urldecode(v)
        end
-       
-       return s
+
+       return table.concat(s, "")
 end
 
 --- Return the URL-decoded equivalent of a string.
@@ -298,3 +304,37 @@ urldecode = protocol.urldecode
 -- @return                     URL-encoded string
 -- @see urldecode
 urlencode = protocol.urlencode
+
+--- Send the given data as JSON encoded string.
+-- @param data         Data to send
+function write_json(x)
+       if x == nil then
+               write("null")
+       elseif type(x) == "table" then
+               local k, v
+               if type(next(x)) == "number" then
+                       write("[ ")
+                       for k, v in ipairs(x) do
+                               write_json(v)
+                               if next(x, k) then
+                                       write(", ")
+                               end
+                       end
+                       write(" ]")
+               else
+                       write("{ ")
+                       for k, v in pairs(x) do
+                       write("%q: " % k)
+                               write_json(v)
+                               if next(x, k) then
+                                       write(", ")
+                               end
+                       end
+                       write(" }")
+               end
+       elseif type(x) == "number" or type(x) == "boolean" then
+               write(tostring(x))
+       elseif type(x) == "string" then
+               write("%q" % tostring(x))
+       end
+end