ASP JSON Utility

http://hanhead.tistory.com/entry/ASP-JSON-Utility

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'**************************************************************************************************************
'* GAB_LIBRARY Copyright (C) 2003 - This file is part of GAB_LIBRARY 
'* For license refer to the license.txt 
'**************************************************************************************************************

'**************************************************************************************************************

'' @CLASSTITLE: JSON
'' @CREATOR: Michal Gabrukiewicz (gabru at grafix.at), Michael Rebec
'' @CONTRIBUTORS: - Cliff Pruitt (opensource at crayoncowboy.com)
'' - Sylvain Lafontaine
'' @CREATEDON: 2007-04-26 12:46
'' @CDESCRIPTION: Comes up with functionality for JSON (http://json.org) to use within ASP.
'' Correct escaping of characters, generating JSON Grammer out of ASP datatypes and structures
'' @REQUIRES: -
'' @OPTIONEXPLICIT: yes
'' @VERSION: 1.4.1

'**************************************************************************************************************
class JSON

'private members
private output, innerCall

'public members
public toResponse ''[bool] should generated results be directly written to the response? default = false

'**********************************************************************************************************
'* constructor 
'**********************************************************************************************************
public sub class_initialize()
newGeneration()
toResponse = false
end sub

'******************************************************************************************
'' @SDESCRIPTION: STATIC! takes a given string and makes it JSON valid
'' @DESCRIPTION: all characters which needs to be escaped are beeing replaced by their
'' unicode representation according to the 
'' RFC4627#2.5 - http://www.ietf.org/rfc/rfc4627.txt?number=4627
'' @PARAM: val [string]: value which should be escaped
'' @RETURN: [string] JSON valid string
'******************************************************************************************
public function escape(val)
dim cDoubleQuote, cRevSolidus, cSolidus
cDoubleQuote = &h22
cRevSolidus = &h5C
cSolidus = &h2F

dim i, currentDigit
for i = 1 to (len(val))
currentDigit = mid(val, i, 1)
if asc(currentDigit) > &h00 and asc(currentDigit) < &h1F then
currentDigit = escapequence(currentDigit)
elseif asc(currentDigit) >= &hC280 and asc(currentDigit) <= &hC2BF then
currentDigit = "\u00" + right(padLeft(hex(asc(currentDigit) - &hC200), 2, 0), 2)
elseif asc(currentDigit) >= &hC380 and asc(currentDigit) <= &hC3BF then
currentDigit = "\u00" + right(padLeft(hex(asc(currentDigit) - &hC2C0), 2, 0), 2)
else
select case asc(currentDigit)
case cDoubleQuote: currentDigit = escapequence(currentDigit)
case cRevSolidus: currentDigit = escapequence(currentDigit)
case cSolidus: currentDigit = escapequence(currentDigit)
end select
end if
escape = escape & currentDigit
next
end function

'******************************************************************************************************************
'' @SDESCRIPTION: generates a representation of a name value pair in JSON grammer
'' @DESCRIPTION: the generation is done fully recursive so the value can be a complex datatype as well. e.g.
'' toJSON("n", array(array(), 2, true), false) or toJSON("n", array(RS, dict, false), false), etc.
'' @PARAM: name [string]: name of the value (accessible with javascript afterwards). leave empty to get just the value
'' @PARAM: val [variant], [int], [float], [array], [object], [dictionary], [recordset]: value which needs
'' to be generated. Conversation of the data types (ASP datatype -> Javascript datatype):
'' NOTHING, NULL -> null, ARRAY -> array, BOOL -> bool, OBJECT -> name of the type, 
'' MULTIDIMENSIONAL ARRAY -> generates a 1 dimensional array (flat) with all values of the multidim array
'' DICTIONARY -> valuepairs. each key is accessible as property afterwards
'' RECORDSET -> array where each row of the recordset represents a field in the array. 
'' fields have properties named after the column names of the recordset (LOWERCASED!)
'' e.g. generate(RS) can be used afterwards r[0].ID
'' INT, FLOAT -> number
'' OBJECT with reflect() method -> returned as object which can be used within JavaScript
'' @PARAM: nested [bool]: is the value pair already nested within another? if yes then the {} are left out.
'' @RETURN: [string] returns a JSON representation of the given name value pair
'' (if toResponse is on then the return is written directly to the response and nothing is returned)
'******************************************************************************************************************
public function toJSON(name, val, nested)
if not nested and not isEmpty(name) then write("{")
if not isEmpty(name) then write("""" & escape(name) & """: ")
generateValue(val)
if not nested and not isEmpty(name) then write("}")
toJSON = output

if innerCall = 0 then newGeneration()
end function

'******************************************************************************************************************
'* generate 
'******************************************************************************************************************
private function generateValue(val)
if isNull(val) then
write("null")
elseif isArray(val) then
generateArray(val)
elseif isObject(val) then
if val is nothing then
write("null")
elseif typename(val) = "Dictionary" then
generateDictionary(val)
elseif typename(val) = "Recordset" then
generateRecordset(val)
else
generateObject(val)
end if
else
'bool
dim varTyp
varTyp = varType(val)
if varTyp = 11 then
if val then write("true") else write("false")
'int, long, byte
elseif varTyp = 2 or varTyp = 3 or varTyp = 17 or varTyp = 19 then
write(cLng(val))
'single, double, currency
elseif varTyp = 4 or varTyp = 5 or varTyp = 6 or varTyp = 14 then
write(replace(cDbl(val), ",", "."))
else
write("""" & escape(val & "") & """")
end if
end if
generateValue = output
end function

'******************************************************************************************************************
'* generateArray 
'******************************************************************************************************************
private sub generateArray(val)
dim item, i
write("[")
i = 0
'the for each allows us to support also multi dimensional arrays
for each item in val
if i > 0 then write(",")
generateValue(item)
i = i + 1
next
write("]")
end sub

'******************************************************************************************************************
'* generateDictionary 
'******************************************************************************************************************
private sub generateDictionary(val)
dim keys, i
innerCall = innerCall + 1
write("{")
keys = val.keys
for i = 0 to uBound(keys)
if i > 0 then write(",")
toJSON keys(i), val(keys(i)), true
next
write("}")
innerCall = innerCall - 1
end sub

'******************************************************************************************************************
'* generateRecordset 
'******************************************************************************************************************
private sub generateRecordset(val)
dim i
write("[")
while not val.eof
innerCall = innerCall + 1
write("{")
for i = 0 to val.fields.count - 1
if i > 0 then write(",")
toJSON lCase(val.fields(i).name), val.fields(i).value, true
next
write("}")
val.movenext()
if not val.eof then write(",")
innerCall = innerCall - 1
wend
write("]")
end sub

'******************************************************************************************************************
'* generateObject 
'******************************************************************************************************************
private sub generateObject(val)
dim props
on error resume next
set props = val.reflect()
if err = 0 then
on error goto 0
innerCall = innerCall + 1
toJSON empty, props, true
innerCall = innerCall - 1
else
on error goto 0
write("""" & escape(typename(val)) & """")
end if
end sub

'******************************************************************************************************************
'* newGeneration 
'******************************************************************************************************************
private sub newGeneration()
output = empty
innerCall = 0
end sub

'******************************************************************************************
'* JsonEscapeSquence 
'******************************************************************************************
private function escapequence(digit)
escapequence = "\u00" + right(padLeft(hex(asc(digit)), 2, 0), 2)
end function

'******************************************************************************************
'* padLeft 
'******************************************************************************************
private function padLeft(value, totalLength, paddingChar)
padLeft = right(clone(paddingChar, totalLength) & value, totalLength)
end function

'******************************************************************************************
'* clone 
'******************************************************************************************
public function clone(byVal str, n)
dim i
for i = 1 to n : clone = clone & str : next
end function

'******************************************************************************************
'* write 
'******************************************************************************************
private sub write(val)
if toResponse then
response.write(val)
else
output = output & val
end if
end sub

end class
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