webmcp
view libraries/mondelefant/mondelefant_atom_connector.lua @ 176:8d7665e0d490
Load JSON library in WebMCP and automatically convert JSON documents in mondelefant-atom-connector
| author | jbe |
|---|---|
| date | Fri Aug 01 22:17:08 2014 +0200 (2014-08-01) |
| parents | 6b435d3c0b14 |
| children | c16292cbcc1e |
line source
1 #!/usr/bin/env lua
3 local _G = _G
4 local _VERSION = _VERSION
5 local assert = assert
6 local error = error
7 local getmetatable = getmetatable
8 local ipairs = ipairs
9 local next = next
10 local pairs = pairs
11 local print = print
12 local rawequal = rawequal
13 local rawget = rawget
14 local rawlen = rawlen
15 local rawset = rawset
16 local select = select
17 local setmetatable = setmetatable
18 local tonumber = tonumber
19 local tostring = tostring
20 local type = type
22 local math = math
23 local string = string
24 local table = table
26 local mondelefant = require("mondelefant")
27 local atom = require("atom")
29 local _M = {}
30 if _ENV then
31 _ENV = _M
32 else
33 _G[...] = _M
34 setfenv(1, _M)
35 end
38 input_converters = setmetatable({}, { __mode = "k" })
40 input_converters["boolean"] = function(conn, value)
41 if value then return "TRUE" else return "FALSE" end
42 end
44 input_converters["number"] = function(conn, value)
45 local str = tostring(value)
46 if string.find(str, "^[0-9%.e%-]+$") then
47 return str
48 else
49 return "'NaN'"
50 end
51 end
53 input_converters[atom.fraction] = function(conn, value)
54 if value.invalid then
55 return "'NaN'"
56 else
57 local n, d = tostring(value.numerator), tostring(value.denominator)
58 if string.find(n, "^%-?[0-9]+$") and string.find(d, "^%-?[0-9]+$") then
59 return "(" .. n .. "::numeric / " .. d .. "::numeric)"
60 else
61 return "'NaN'"
62 end
63 end
64 end
66 input_converters[atom.date] = function(conn, value)
67 return conn:quote_string(tostring(value)) .. "::date"
68 end
70 input_converters[atom.timestamp] = function(conn, value)
71 return conn:quote_string(tostring(value)) -- don't define type
72 end
74 input_converters[atom.time] = function(conn, value)
75 return conn:quote_string(tostring(value)) .. "::time"
76 end
79 output_converters = setmetatable({}, { __mode = "k" })
81 output_converters.int8 = function(str) return atom.integer:load(str) end
82 output_converters.int4 = function(str) return atom.integer:load(str) end
83 output_converters.int2 = function(str) return atom.integer:load(str) end
85 output_converters.numeric = function(str) return atom.number:load(str) end
86 output_converters.float4 = function(str) return atom.number:load(str) end
87 output_converters.float8 = function(str) return atom.number:load(str) end
89 output_converters.bool = function(str) return atom.boolean:load(str) end
91 output_converters.date = function(str) return atom.date:load(str) end
93 local timestamp_loader_func = function(str)
94 local year, month, day, hour, minute, second = string.match(
95 str,
96 "^([0-9][0-9][0-9][0-9])%-([0-9][0-9])%-([0-9][0-9]) ([0-9]?[0-9]):([0-9][0-9]):([0-9][0-9])"
97 )
98 if year then
99 return atom.timestamp{
100 year = tonumber(year),
101 month = tonumber(month),
102 day = tonumber(day),
103 hour = tonumber(hour),
104 minute = tonumber(minute),
105 second = tonumber(second)
106 }
107 else
108 return atom.timestamp.invalid
109 end
110 end
111 output_converters.timestamp = timestamp_loader_func
112 output_converters.timestamptz = timestamp_loader_func
114 local time_loader_func = function(str)
115 local hour, minute, second = string.match(
116 str,
117 "^([0-9]?[0-9]):([0-9][0-9]):([0-9][0-9])"
118 )
119 if hour then
120 return atom.time{
121 hour = tonumber(hour),
122 minute = tonumber(minute),
123 second = tonumber(second)
124 }
125 else
126 return atom.time.invalid
127 end
128 end
129 output_converters.time = time_loader_func
130 output_converters.timetz = time_loader_func
132 output_converters.json = json.import
133 output_converters.jsonb = json.import
135 mondelefant.postgresql_connection_prototype.type_mappings = {
136 int8 = atom.integer,
137 int4 = atom.integer,
138 int2 = atom.integer,
139 bool = atom.boolean,
140 date = atom.date,
141 timestamp = atom.timestamp,
142 time = atom.time,
143 text = atom.string,
144 varchar = atom.string,
145 json = json,
146 jsonb = json,
147 }
150 function mondelefant.postgresql_connection_prototype.input_converter(conn, value, info)
151 if value == nil then
152 return "NULL"
153 else
154 local converter =
155 input_converters[getmetatable(value)] or
156 input_converters[type(value)]
157 if converter then
158 return converter(conn, value)
159 else
160 return conn:quote_string(tostring(value))
161 end
162 end
163 end
165 function mondelefant.postgresql_connection_prototype.output_converter(conn, value, info)
166 if value == nil then
167 return nil
168 else
169 local converter = output_converters[info.type]
170 if converter then
171 return converter(value)
172 else
173 return value
174 end
175 end
176 end
178 return _M
181 --[[
183 db = assert(mondelefant.connect{engine='postgresql', dbname='test'})
184 result = db:query{'SELECT ? + 1', atom.date{ year=1999, month=12, day=31}}
185 print(result[1][1].year)
187 --]]