I have a handler that uploads a KML file and returns JSON with the KML file as an attribute:

context.Response.Write("{\"name\":\"" + FileName + 
"\",\"type\":\"" + FileType + 
"\",\"size\":\"" + FileSize + 
"\",\"region_id\":\"" + regionID + 
"\",\"kml\":\"" + HttpUtility.HtmlEncode(xmlData) + "\"}");

As you can see, I'm trying to encode the KML with HttpUtility.HtmlEncode but I get an error in my response:

uncaught exception: Invalid JSON

How can I property encode the XML/KML file in C# so I can later decode it in JavaScript?

Edit #1: per Cheeso's ment I'm using ASP.NET, .NET Version 4 on IIS 7.5 Windows 7. My handler is a ashx file. The response works fine if I leave out the KML data (HttpUtility.HtmlEncode(xmlData)) from the response.

Edit #2 I also tried using System.Web.Script.Serialization.JavaScriptSerializer per the moderator's ment. I used it like such:

System.Web.Script.Serialization.JavaScriptSerializer serializer;
context.Response.Write("{\"name\":\"" + FileName + 
"\",\"type\":\"" + FileType + 
"\",\"size\":\"" + FileSize + 
"\",\"region_id\":\"" + regionID + 
"\",\"kml\":\"" + serializer.Serialize(xmlData) + "\"}");

I still get the same "Invalid JSON" error.

I have a handler that uploads a KML file and returns JSON with the KML file as an attribute:

context.Response.Write("{\"name\":\"" + FileName + 
"\",\"type\":\"" + FileType + 
"\",\"size\":\"" + FileSize + 
"\",\"region_id\":\"" + regionID + 
"\",\"kml\":\"" + HttpUtility.HtmlEncode(xmlData) + "\"}");

As you can see, I'm trying to encode the KML with HttpUtility.HtmlEncode but I get an error in my response:

uncaught exception: Invalid JSON

How can I property encode the XML/KML file in C# so I can later decode it in JavaScript?

Edit #1: per Cheeso's ment I'm using ASP.NET, .NET Version 4 on IIS 7.5 Windows 7. My handler is a ashx file. The response works fine if I leave out the KML data (HttpUtility.HtmlEncode(xmlData)) from the response.

Edit #2 I also tried using System.Web.Script.Serialization.JavaScriptSerializer per the moderator's ment. I used it like such:

System.Web.Script.Serialization.JavaScriptSerializer serializer;
context.Response.Write("{\"name\":\"" + FileName + 
"\",\"type\":\"" + FileType + 
"\",\"size\":\"" + FileSize + 
"\",\"region_id\":\"" + regionID + 
"\",\"kml\":\"" + serializer.Serialize(xmlData) + "\"}");

I still get the same "Invalid JSON" error.

• c#
• javascript
• asp
• xml
• json

• 1 Why not use a proper JSON encoding library? A list is here: json – Pekka Commented May 26, 2011 at 17:50
• 8 Why wouldn't you use JavaScriptSerializer or JSON.NET for this? – Marc Gravell Commented May 26, 2011 at 17:50
• 3 @Pekka oh C# doesn't at all - nor can it handle XML, regex, or even DateTime. Good job that the .NET BCL has, though :) – Marc Gravell Commented May 26, 2011 at 17:51
• 3 @capdragon right; now that I'm back off mobile, I have added an example. Frankly, your tone above was both offensive and inappropriate. If you don't choose to use an object-level serializer that it up to you, but it is (as shown) a very valid answer to this problem. Especially considering that you haven't guarded the calling client by ensuring your own data is correctly encoded (which may or may not be a problem, depending on the candidate values of FileName, FileType etc). – Marc Gravell Commented May 26, 2011 at 19:57
• 3 It's @Marc by the way; I don't mind either-way, but I won't get a notification alert from @Mark. It is unfortunate that you took offence - none was intended. – Marc Gravell Commented May 26, 2011 at 22:45

2 Answers 2

You want to build JSON, right... and apparently it is ridiculous of me to suggest a JSON serializer.... yet:

string FileName = "foo.txt", FileType = "csv";
int FileSize = 1134, regionID = 12;
string xml = "<foo><bar/></foo>";

string json= new JavaScriptSerializer().Serialize(new {
    name = FileName,
    type = FileType,
    size = FileSize,
    region_id = regionID,
    kml = xml
});

In the majority of cases, using a pre-canned serializer is both more convenient and more robust against edge-cases of data.

An HTML Encoder encodes < as < and so forth. That doesn't help you get XML into JSON format. What you want is a JavaScript Encode. Use HttpUtility.JavaScriptStringEncode

http://msdn.microsoft./en-us/library/dd991914.aspx