Ticket #660 (enhancement)

The topic is here http://www.pradosoft.com/forum/index.php/topic,4491.0.html

I've talked to Wei about this.

A (long) summary: JSON uses UTF-8 internally, so JSON encoding is made using UTF-8 source (and JSON decoding is made using UTF-8 target). This prevents setting of any ActiveWidget's properties to non-UTF-8 strings. Instead, i propose using Globalization.charset to encode/decode PRADO-side strings to UTF-8 just before JSON encoding, and after JSON decoding (using the assumption "Globalization.charset denotes application's encoding")

There are two possible ways; one is to make these encoding conversion just before TJSON::encode() is called in callback handling functions, and do it after TJSON::decode() when parsing JSON-encoded input data from javascript. This fixes the problem only for AJAX callbacks. I think the more "right" method is, to put this charset conversion directly in TJSON::encode() and TJSON::decode(), changing these functions definitions from "strings provided to/from these functions are ALWAYS in UTF-8" to "strings provided to/from these functions are in Globalization.Charset if specified, UTF-8 otherwise".

Using the second way, not only AJAX callbacks can be handled, but a JSON Service can be created with a different charset than UTF-8 using Globalization.charset