Miva-JSON conversion, revisited

In 2011, I wrote some functions for converting between Miva Script objects and JSON text. In the years since then, JSON has become more common for many types of data transfer and storage; it's not just for AJAX any more. It's replacing XML as a popular format for exchanging data over the Internet, and for storing it in a way that's compatible with many platforms and programs.

The Miva VM and compiler now support a built-in function, miva_json_decode(), for converting JSON to a Miva Script object. But there is no built-in function for going the other way, from Miva to JSON. So the function I wrote for that is still useful. Ray Yates and Timothy Bolton have made some bug fixes and improvements. A copy of the latest version is listed below.

My original article is still on-line at http://TheMagicM.com/jsonize.mvc. It includes a demo script so you can try the conversions yourself. It also has a link to download the source code for both the functions and the demo script.

<MvCOMMENT> ========== ========== ========== ========== ========== ========== JSON.mv conversion function Syntax and Usage: Json_Stringify(data_object) Returns a Json string data_object = structured miva data object Usage: <MvEVAL EXPR="{ Json_Stringify(l.all_settings:basket) }"> ========== ========== ========== ========== ========== ========== </MvCOMMENT> <MvFUNCTION NAME="Json_Stringify" PARAMETERS="data VAR" STANDARDOUTPUTLEVEL=""> <MvCOMMENT> Added an escaping arrays for stringifying, Timothy Bolton, 4/12/2012 renamed JSON() to Json_Stringify() 3/21/2010 (Original work by KAM, 3/2011) Create JSON text from Miva Data: variable, array, structure, etc. </MvCOMMENT> <MvASSIGN NAME = "l.search_array" INDEX = "1" VALUE = "{ asciichar(92) $ 'b' }"> <MvASSIGN NAME = "l.search_array" INDEX = "2" VALUE = "{ asciichar(92) $ 't' }"> <MvASSIGN NAME = "l.search_array" INDEX = "3" VALUE = "{ asciichar(92) $ 'n' }"> <MvASSIGN NAME = "l.search_array" INDEX = "4" VALUE = "{ asciichar(92) $ 'f' }"> <MvASSIGN NAME = "l.search_array" INDEX = "5" VALUE = "{ asciichar(92) $ 'r' }"> <MvASSIGN NAME = "l.search_array" INDEX = "6" VALUE = "{ asciichar(34) }"> <MvASSIGN NAME = "l.search_array" INDEX = "7" VALUE = "{ asciichar(92) $ asciichar(92) }"> <MvASSIGN NAME = "l.replace_array" INDEX = "1" VALUE = "{ asciichar(92) $ asciichar(92) $ 'b' }"> <MvASSIGN NAME = "l.replace_array" INDEX = "2" VALUE = "{ asciichar(92) $ asciichar(92) $ 't' }"> <MvASSIGN NAME = "l.replace_array" INDEX = "3" VALUE = "{ asciichar(92) $ asciichar(92) $ 'n' }"> <MvASSIGN NAME = "l.replace_array" INDEX = "4" VALUE = "{ asciichar(92) $ asciichar(92) $ 'f' }"> <MvASSIGN NAME = "l.replace_array" INDEX = "5" VALUE = "{ asciichar(92) $ asciichar(92) $ 'r' }"> <MvASSIGN NAME = "l.replace_array" INDEX = "6" VALUE = "{ asciichar(92) $ asciichar(34) }"> <MvASSIGN NAME = "l.replace_array" INDEX = "7" VALUE = "{ asciichar(92) $ asciichar(92) $ asciichar(92) $ asciichar(92) }"> <MvASSIGN NAME="l.serial" VALUE="{ miva_array_serialize(l.data) }"> <MvASSIGN NAME="l.first" VALUE="{ substring(l.serial, 1, 1) }"> <MvIF EXPR="{ l.first EQ '=' }"> <MvIF EXPR="{ (len(l.data)) AND (l.data EQ (l.data + 0)) }"> <MvCOMMENT> --- valid number </MvCOMMENT> <MvCOMMENT> 7/15/2014 Special case for number with leading zeros </MvCOMMENT> <MvIF EXPR="{ len(l.data) GT 1 }"> <MvIF EXPR="{ substring(l.data,1,1) EQ '0' }"> <MvASSIGN NAME="l.data" VALUE="{ '\"' $ l.data $ '\"' }"> </MvIF> </MvIF> <MvFUNCRETURN VALUE="{ l.data }"> <MvELSE> <MvFUNCRETURN VALUE="{ '\"' $ glosub_array(l.data, l.search_array, l.replace_array) $ '\"' }"> </MvIF> </MvIF> <MvASSIGN NAME="l.type" VALUE="{ l.first }"> <MvCOMMENT> --- will be "[" or ":" to indicate array or structure --- Loop thru all elements of the array or structure. Collect a list of the top-level children's "member IDs." --- A member ID is either a number enclosed in brackets (array), or a colon followed by the member name (structure). </MvCOMMENT> <MvWHILE EXPR="{ gettoken(l.serial, ',', l.n + 1) }"> <MvASSIGN NAME="l.n" VALUE="{ l.n + 1 }"> <MvASSIGN NAME="l.member" VALUE="{ gettoken(l.serial, ',', l.n) }"> <MvASSIGN NAME="l.address" VALUE="{ gettoken(l.member, '=', 1) }"> <MvIF EXPR="{ l.type EQ '[' }"> <MvASSIGN NAME="l.mid" VALUE="{ substring(l.address, 1, (']' IN l.address)) }"> <MvELSE> <MvASSIGN NAME="l.mid" VALUE="{ ':' $ gettoken( gettoken(l.address, ':', 2), '[', 1) }"> </MvIF> <MvASSIGN NAME="l.mids" VALUE="{ AppendUnique(l.mids, l.mid) }"> </MvWHILE> <MvCOMMENT> --- Call ourself recursively on each of the children. </MvCOMMENT> <MvWHILE EXPR="{ gettoken(l.mids, ',', l.m + 1) }"> <MvASSIGN NAME="l.m" VALUE="{ l.m + 1 }"> <MvASSIGN NAME="l.mid" VALUE="{ gettoken(l.mids, ',', l.m) }"> <MvASSIGN NAME="l.childname" VALUE="{ 'l.data' $ l.mid }"> <MvREFERENCE NAME="l.child" VARIABLE="{ l.childname }"> <MvIF EXPR="{ l.m GT 1 }"> <MvASSIGN NAME="l.json" VALUE="{ l.json $ ', ' }"> </MvIF> <MvIF EXPR="{ l.type EQ ':' }"> <MvASSIGN NAME="l.json" VALUE="{ l.json $ '\"' $ tolower(substring(l.mid, 2, 9999)) $ '\": ' }"> </MvIF> <MvASSIGN NAME="l.json" VALUE="{ l.json $ Json_Stringify(l.child) }"> </MvWHILE> <MvIF EXPR="{ NOT len(l.json) }"> <MvASSIGN NAME="l.json" VALUE="{ '\"\"' }"> <MvELSEIF EXPR="{ l.type EQ '[' }"> <MvASSIGN NAME="l.json" VALUE="{ ' [' $ l.json $ ']' }"> <MvELSE> <MvASSIGN NAME="l.json" VALUE="{ ' {' $ l.json $ '}' }"> </MvIF> <MvFUNCRETURN VALUE="{ l.json }"> </MvFUNCTION>