5 Several common useful Lua functions
11 Copyright 2008 Steven Barth <steven@midlink.org>
13 Licensed under the Apache License, Version 2.0 (the "License");
14 you may not use this file except in compliance with the License.
15 You may obtain a copy of the License at
17 http://www.apache.org/licenses/LICENSE-2.0
19 Unless required by applicable law or agreed to in writing, software
20 distributed under the License is distributed on an "AS IS" BASIS,
21 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
22 See the License for the specific language governing permissions and
23 limitations under the License.
27 module("luci.util", package.seeall)
30 -- Lua simplified Python-style OO class support emulation
34 local create = function(class, ...)
36 setmetatable(inst, {__index = class})
39 local stat, err = pcall(inst.__init__, inst, ...)
48 local classmeta = {__call = create}
51 classmeta.__index = base
54 setmetatable(class, classmeta)
59 -- Clones an object (deep on-demand)
60 function clone(object, deep)
63 for k, v in pairs(object) do
64 if deep and type(v) == "table" then
70 setmetatable(copy, getmetatable(object))
76 -- Combines two or more numerically indexed tables into one
79 for i, a in ipairs(arg) do
80 for j, v in ipairs(a) do
81 table.insert(result, v)
88 -- Checks whether a table has an object "value" in it
89 function contains(table, value)
90 for k,v in pairs(table) do
99 -- Dumps a table to stdout (useful for testing and debugging)
100 function dumptable(t, i)
102 for k,v in pairs(t) do
103 print(string.rep("\t", i) .. k, v)
104 if type(v) == "table" then
111 -- Escapes all occurences of c in s
112 function escape(s, c)
114 return s:gsub(c, "\\" .. c)
118 -- Populate obj in the scope of f as key
119 function extfenv(f, key, obj)
120 local scope = getfenv(f)
125 -- Checks whether an object is an instanceof class
126 function instanceof(object, class)
127 local meta = getmetatable(object)
128 while meta and meta.__index do
129 if meta.__index == class then
132 meta = getmetatable(meta.__index)
138 -- Creates valid XML PCDATA from a string
139 function pcdata(value)
140 value = value:gsub("&", "&")
141 value = value:gsub('"', """)
142 value = value:gsub("'", "'")
143 value = value:gsub("<", "<")
144 return value:gsub(">", ">")
148 -- Resets the scope of f doing a shallow copy of its scope into a new table
150 setfenv(f, clone(getfenv(f)))
154 -- Splits a string into an array
155 function split(str, pat, max, regex)
175 local s, e = str:find(pat, c, not regex)
176 table.insert(t, str:sub(c, s and s - 1))
178 c = e and e + 1 or #str + 1
179 until not s or max < 0
184 -- Removes whitespace from beginning and end of a string
186 local s = str:gsub("^%s*(.-)%s*$", "%1")
190 -- Updates given table with new values
191 function update(t, updates)
192 for k, v in pairs(updates) do
198 -- Updates the scope of f with "extscope"
199 function updfenv(f, extscope)
200 update(getfenv(f), extscope)
204 -- Validates a variable
205 function validate(value, cast_number, cast_int)
206 if cast_number or cast_int then
207 value = tonumber(value)
210 if cast_int and value and not(value % 1 == 0) then