Question

I am creating a web application that allows a user to load data in JSON format. I am currently using the following function to read JSON files that I have saved on my local disk:

function retrieveJSON(url, callback)
{
  // this is needed because FireFox tries to parse files as XML
  $.ajaxSetup({ mimeType: "text/plain" });

  // send out an AJAX request and return the result
  $.getJSON(url, function(response) {
    console.log("Data acquired successfully");
    callback(response);
  }).error(function(jqXHR, textStatus, errorThrown) {
    console.log("Error...\n" + textStatus + "\n" + errorThrown);
  });
}

This works perfectly for well-formed JSON data. However, for malformed data, the console log displays the following:

Error...
parsererror
SyntaxError: JSON.parse: unexpected character

This is almost entirely unhelpful because it does not tell me what the unexpected character is or what line number it can be found on. I could use a JSON validator to correct the file on my local disk, but this is not an option when the page is loading files from remote URLs on the web.

How can I obtain the location of any error? I would like to obtain the token if possible, but I need to obtain the line number at minimum. There is a project requirement to display an excerpt of the JSON code to the user and highlight the line where any error occurred.

I am currently using jQuery, but jQuery is not a project requirement, so if another API or JSON parser provides this functionality, I could use that instead.

Answer 1

Yeah, life with deadlines is never easy :).

This might help you out, after couple of hours googling around, I’ve found jsonlint on Git Hub. It looks promising, it includes a shell script that could be used on server side, and there is a browser JavaScript version of it that seems to be exactly what you were looking for.

Hope that this will help You.