Within my HTTP REQUEST, a valid JSON string is present with a double quote in the middle of the name "jo\"hn" escaped. This was captured by Fiddler Web Debugger.
{"name":"firstName","value":"jo\"hn"},
It's important to note that the request submission process utilizes the standard jQuery $.ajax(..) call as shown in this article without any issues.
Encountering Server-side Issues
Upon reaching my C# ASMX web service method, I notice that the C# string value received has the middle double quote unescaped (no backslash). This leads to deserialization errors as mentioned below.
This discrepancy occurs before the value reaches my web method. It appears that ASP.NET processes the string internally, removing escapes and reconstructing it without them, ultimately altering the original value instead of passing it verbatim to the web method parameter.
The C# String is:
{"name":"firstName","value":"jo"hn"},
The ASMX Web method structure is something like:
using System.Web.Script.Serialization;
using System.Web.Script.Services;
[WebMethod]
[ScriptMethod(ResponseFormat = System.Web.Script.Services.ResponseFormat.Json)]
public string saveData(string values)
{
JavaScriptSerializer json = new JavaScriptSerializer();
request = json.Deserialize<List<NameValuePair>>(values.ToString());
// ^^^ KABOOM!
An understandable exception message is:
{"Invalid object passed in, ':' or '}' expected. (423): [{\"name\":\"plc$lt$zoneHeaderTopNav$searchBoxTopNav$txtWord\",\"value\":\"\"},{\"name\":\"salutation\",\"value\":\"Mr\"},{\"name\":\"firstName\",\"value\":\"joh\"n\"},{\"name\":\"lastName\",\"value\":\"smith\"},{\"name\":\"initial\",\"value\":\"d\"}]}
How can I resolve this issue without moving away from classic ASMX web services?
Possible solutions include implementing a front handler to clean up incoming requests or performing string cleanup at the beginning of the web service method. Another option could be trying a different JSON library.
However, I am curious if there is an easier solution such as tweaking configuration settings, using an Attribute, or overloading methods to address the problem.
I have searched extensively online but most resources focus on handling JSON data returned from the server to the client rather than addressing issues at this point in the process.
Addendum Note: detailed client-side call information requested by Darin Dimitrov
UPDATE: Darin's Answer inline for easy reference
function SaveDraft() {
$.checklist.checkvalid();
var formObj = $(':input:not([type=hidden])').serializeArray();
var request = JSON.stringify(formObj);
request = request.replace(/'/g, "");
$.ajax({
url: "/Service.asmx/saveData",
type: "POST",
// *** Original erroneous line: uses string concat - commented out
// data: "{'values':'" + request + "'}",
// *** CORRECTED LINE: provides an object instead of a string and calls JSON stringify.
data: JSON.stringify({ values: request }),
dataType: "json",
contentType: "application/json; charset=utf-8",
success: SaveDraftSuccess,
error: SaveDraftFail
});
}
Note: This revised approach accurately produces the valid JSON fragment displayed at the beginning of the question.