source: Dev/trunk/src/client/dojo/json.js @ 501

define(["./has"], function(has){
        "use strict";
        var hasJSON = typeof JSON != "undefined";
        has.add("json-parse", hasJSON); // all the parsers work fine
                // Firefox 3.5/Gecko 1.9 fails to use replacer in stringify properly https://bugzilla.mozilla.org/show_bug.cgi?id=509184
        has.add("json-stringify", hasJSON && JSON.stringify({a:0}, function(k,v){return v||1;}) == '{"a":1}');

        /*=====
        return {
                // summary:
                //              Functions to parse and serialize JSON

                parse: function(str, strict){
                        // summary:
                        //              Parses a [JSON](http://json.org) string to return a JavaScript object.
                        // description:
                        //              This function follows [native JSON API](https://developer.mozilla.org/en/JSON)
                        //              Throws for invalid JSON strings. This delegates to eval() if native JSON
                        //              support is not available. By default this will evaluate any valid JS expression.
                        //              With the strict parameter set to true, the parser will ensure that only
                        //              valid JSON strings are parsed (otherwise throwing an error). Without the strict
                        //              parameter, the content passed to this method must come
                        //              from a trusted source.
                        // str:
                        //              a string literal of a JSON item, for instance:
                        //              `'{ "foo": [ "bar", 1, { "baz": "thud" } ] }'`
                        // strict:
                        //              When set to true, this will ensure that only valid, secure JSON is ever parsed.
                        //              Make sure this is set to true for untrusted content. Note that on browsers/engines
                        //              without native JSON support, setting this to true will run slower.
                },
                stringify: function(value, replacer, spacer){
                        // summary:
                        //              Returns a [JSON](http://json.org) serialization of an object.
                        // description:
                        //              Returns a [JSON](http://json.org) serialization of an object.
                        //              This function follows [native JSON API](https://developer.mozilla.org/en/JSON)
                        //              Note that this doesn't check for infinite recursion, so don't do that!
                        // value:
                        //              A value to be serialized.
                        // replacer:
                        //              A replacer function that is called for each value and can return a replacement
                        // spacer:
                        //              A spacer string to be used for pretty printing of JSON
                        // example:
                        //              simple serialization of a trivial object
                        //      |       define(["dojo/json"], function(JSON){
                        //      |               var jsonStr = JSON.stringify({ howdy: "stranger!", isStrange: true });
                        //      |               doh.is('{"howdy":"stranger!","isStrange":true}', jsonStr);
                }
        };
        =====*/

        if(has("json-stringify")){
                return JSON;
        }else{
                var escapeString = function(/*String*/str){
                        // summary:
                        //              Adds escape sequences for non-visual characters, double quote and
                        //              backslash and surrounds with double quotes to form a valid string
                        //              literal.
                        return ('"' + str.replace(/(["\\])/g, '\\$1') + '"').
                                replace(/[\f]/g, "\\f").replace(/[\b]/g, "\\b").replace(/[\n]/g, "\\n").
                                replace(/[\t]/g, "\\t").replace(/[\r]/g, "\\r"); // string
                };
                return {
                        parse: has("json-parse") ? JSON.parse : function(str, strict){
                                if(strict && !/^([\s\[\{]*(?:"(?:\\.|[^"])*"|-?\d[\d\.]*(?:[Ee][+-]?\d+)?|null|true|false|)[\s\]\}]*(?:,|:|$))+$/.test(str)){
                                        throw new SyntaxError("Invalid characters in JSON");
                                }
                                return eval('(' + str + ')');
                        },
                        stringify: function(value, replacer, spacer){
                                var undef;
                                if(typeof replacer == "string"){
                                        spacer = replacer;
                                        replacer = null;
                                }
                                function stringify(it, indent, key){
                                        if(replacer){
                                                it = replacer(key, it);
                                        }
                                        var val, objtype = typeof it;
                                        if(objtype == "number"){
                                                return isFinite(it) ? it + "" : "null";
                                        }
                                        if(objtype == "boolean"){
                                                return it + "";
                                        }
                                        if(it === null){
                                                return "null";
                                        }
                                        if(typeof it == "string"){
                                                return escapeString(it);
                                        }
                                        if(objtype == "function" || objtype == "undefined"){
                                                return undef; // undefined
                                        }
                                        // short-circuit for objects that support "json" serialization
                                        // if they return "self" then just pass-through...
                                        if(typeof it.toJSON == "function"){
                                                return stringify(it.toJSON(key), indent, key);
                                        }
                                        if(it instanceof Date){
                                                return '"{FullYear}-{Month+}-{Date}T{Hours}:{Minutes}:{Seconds}Z"'.replace(/\{(\w+)(\+)?\}/g, function(t, prop, plus){
                                                        var num = it["getUTC" + prop]() + (plus ? 1 : 0);
                                                        return num < 10 ? "0" + num : num;
                                                });
                                        }
                                        if(it.valueOf() !== it){
                                                // primitive wrapper, try again unwrapped:
                                                return stringify(it.valueOf(), indent, key);
                                        }
                                        var nextIndent= spacer ? (indent + spacer) : "";
                                        /* we used to test for DOM nodes and throw, but FF serializes them as {}, so cross-browser consistency is probably not efficiently attainable */ 
                                
                                        var sep = spacer ? " " : "";
                                        var newLine = spacer ? "\n" : "";
                                
                                        // array
                                        if(it instanceof Array){
                                                var itl = it.length, res = [];
                                                for(key = 0; key < itl; key++){
                                                        var obj = it[key];
                                                        val = stringify(obj, nextIndent, key);
                                                        if(typeof val != "string"){
                                                                val = "null";
                                                        }
                                                        res.push(newLine + nextIndent + val);
                                                }
                                                return "[" + res.join(",") + newLine + indent + "]";
                                        }
                                        // generic object code path
                                        var output = [];
                                        for(key in it){
                                                var keyStr;
                                                if(it.hasOwnProperty(key)){
                                                        if(typeof key == "number"){
                                                                keyStr = '"' + key + '"';
                                                        }else if(typeof key == "string"){
                                                                keyStr = escapeString(key);
                                                        }else{
                                                                // skip non-string or number keys
                                                                continue;
                                                        }
                                                        val = stringify(it[key], nextIndent, key);
                                                        if(typeof val != "string"){
                                                                // skip non-serializable values
                                                                continue;
                                                        }
                                                        // At this point, the most non-IE browsers don't get in this branch 
                                                        // (they have native JSON), so push is definitely the way to
                                                        output.push(newLine + nextIndent + keyStr + ":" + sep + val);
                                                }
                                        }
                                        return "{" + output.join(",") + newLine + indent + "}"; // String
                                }
                                return stringify(value, "", "");
                        }
                };
        }
});