Implementing Mozilla's toSource() method in Internet Explorer.

Question

Has anyone implemented Mozilla's Object.toSource() method for Internet Explorer and other non-Gecko browsers? I'm looking for a lightweight way to serialize simple objects into strings.

Answer 1

If matching the exact serialization format of Firefox is not your aim, you could use one of the JavaScript JSON serialization/deserialization libraries listed at http://json.org. Using a standard scheme like JSON may be better than mimicking the proprietary Gecko format.

Answer 2

You could do something like this:

Object.prototype.getSource = function() {
    var output = [], temp;
    for (var i in this) {
        if (this.hasOwnProperty(i)) {
            temp = i + ":";
            switch (typeof this[i]) {
                case "object" :
                    temp += this[i].getSource();
                    break;
                case "string" :
                    temp += "\"" + this[i] + "\"";    // add in some code to escape quotes
                    break;
                default :
                    temp += this[i];
            }
            output.push(temp);
        }
    }
    return "{" + output.join() + "}";
}

Answer 3

See also JavaScript data formatting/pretty printer. I think the routine exports in valid JS format, so it can be eval to get it back.

[EDIT] Actually, not! It is OK for quick dump but not for real serialization. I improved it, result below:

function SerializeObject(obj, indentValue)
{
  var hexDigits = "0123456789ABCDEF";
  function ToHex(d)
  {
    return hexDigits[d >> 8] + hexDigits[d & 0x0F];
  }
  function Escape(string)
  {
    return string.replace(/[\x00-\x1F'\\]/g,
        function (x)
        {
          if (x == "'" || x == "\\") return "\\" + x;
          return "\\x" + ToHex(String.charCodeAt(x, 0));
        })
  }

  var indent;
  if (indentValue == null)
  {
    indentValue = "";
    indent = ""; // or " "
  }
  else
  {
    indent = "\n";
  }
  return GetObject(obj, indent).replace(/,$/, "");

  function GetObject(obj, indent)
  {
    if (typeof obj == 'string')
    {
      return "'" + Escape(obj) + "',";
    }
    if (obj instanceof Array)
    {
      result = indent + "[";
      for (var i = 0; i < obj.length; i++)
      {
        result += indent + indentValue +
            GetObject(obj[i], indent + indentValue);
      }
      result += indent + "],";
      return result;
    }
    var result = "";
    if (typeof obj == 'object')
    {
      result += indent + "{";
      for (var property in obj)
      {
        result += indent + indentValue + "'" +
            Escape(property) + "' : " +
            GetObject(obj[property], indent + indentValue);
      }
      result += indent + "},";
    }
    else
    {
      result += obj + ",";
    }
    return result.replace(/,(\n?\s*)([\]}])/g, "$1$2");
  }
}

indentValue can be null, "", " ", "\t" or whatever. If null, no indentation, output a rather compact result (could use less spaces...).

I could use an array to stack the results then join them, but unless you have giant objects, string concatenation should be good enough...
Also doesn't handle cyclic references...