source: branches/samba-3.5.x/swat2/scripting/client/encoder.js

/*
        client side js functions for encoding/decoding objects into linear strings

        Copyright Andrew Tridgell 2005
        released under the GNU GPL Version 3 or later
*/
/*
        usage:

          enc = encodeObject(obj);
          obj = decodeObject(enc);

       The encoded format of the object is a string that is safe to
       use in URLs

       Note that only data elements are encoded, not functions
*/

function count_members(o) {
        var i, count = 0;
        for (i in o) { 
                count++;  
        }
        return count;
}

function encodeObject(o) {
        var i, r = count_members(o) + ":";
        for (i in o) {
                var t = typeof(o[i]);
                if (t == 'object') {
                        r = r + "" + i + ":" + t + ":" + encodeObject(o[i]);
                } else if (t == 'string') {
                        var s = encodeURIComponent(o[i]).replace(/%/g,'#');
                        r = r + "" + i + ":" + t + ":" + s + ":";
                } else if (t == 'boolean' || t == 'number') {
                        r = r + "" + i + ":" + t + ":" + o[i] + ":";
                } else if (t == 'undefined' || t == 'null') {
                        r = r + "" + i + ":" + t + ":";
                } else if (t != 'function') {
                        alert("Unable to encode type " + t);
                }
        }
        return r;
}

function decodeObjectArray(a) {
        var o = new Object();
        var i, count = a[a.i]; a.i++;
        for (i=0;i<count;i++) {
                var name  = a[a.i]; a.i++;
                var type  = a[a.i]; a.i++;
                var value;
                if (type == 'object') {
                        o[name] = decodeObjectArray(a);
                } else if (type == "string") {
                        value = decodeURIComponent(a[a.i].replace(/#/g,'%')); a.i++;
                        o[name] = value;
                } else if (type == "boolean") {
                        value = a[a.i]; a.i++;
                        if (value == 'true') {
                                o[name] = true;
                        } else {
                                o[name] = false;
                        }
                } else if (type == "undefined") {
                        o[name] = undefined;
                } else if (type == "null") {
                        o[name] = null;
                } else if (type == "number") {
                        value = a[a.i]; a.i++;
                        o[name] = value * 1;
                } else {
                        alert("Unable to delinearise type " + type);
                }
        }
        return o;
}

function decodeObject(str) {
        var a = str.split(':');
        a.i = 0;
        return decodeObjectArray(a);
}