###INTRODUCTION

JSONVALUE is a friendly C++ class for parsing JSON string to C++ object, and creating a C++ representation of JSON string. Several advatages of this C++ JSON class are:

• strict and loose mode
• variant data type
• simple API
• depends on STL only.

Both ANSI and UNICODE strings are supported for parsing and stringification.

###USAGE

JSON C++ value, object and array can be created and added and retrieved using simple assignment operator (=) and object assignment operator ([]).

JSON string parsing support strict parsing as well as loose parsing via additional flags passed to Parse() function.

In loose parsing, user can opt to:

• allow unquote name
• allow white space control character
• allow single quote

In loose stringification, user can opt to:

• create unquote name
• create name with single quote
• pretty print output with TAB character or SPACE character
• output date as locale date

In strict mode:

• date is created in ISO date format: YYYY-MM-DD HH:MM:SS
• all names and strings are double quoted

###EXAMPLES

Sample code to parse a JSON string:

Strict mode:

Parse(json_string);

Strict mode, with error messages: err is meaningful if Parse() returns false.

JSONERROR err;
Parse(json_string, 0, &err);

Loose mode: by default JSON_FLAG_LOOSE allow unquote name, white space control characters and single quote name. User can further restrict the level of looseness by passing different JSON_FLAG_xx values into Parse() function.

Parse(json_string, JSON_FLAG_LOOSE);

Loose mode, with error messages: err is meaningful if Parse() returns false.

JSONERROR err;
Parse(json_string, JSON_FLAG_LOOSE, &err);

Sample code to create JSON string:

JSONVALUE j;
j[_T("double")].Push(0.32);
j[_T("test")][_T("boolean")] = true;
string a;
j.ToString(a);

The default strict mode will generate the following JSON string:

{"double":[0.32],"test":{"boolean":true}}

User can further customize the output string by passing JSONFORMAT structure into ToString() function, which he can control the indent space (if JSON_FLAG_PRETTYPRINTSPACE is specified), floating point format and date format.

###NOTE This code was originally developed for Ecava IGX WEB SCADA, if you know what's SCADA then you may be interested to download a copy to see this peace of code performs in real life application.