Can I set an unlimited length for maxJsonLength in

Question

I am using the autocomplete feature of jQuery. When I try to retrieve the list of more then 17000 records (each won't have more than 10 char length), it's exceeding the length and throws the error:

Exception information:
Exception type: InvalidOperationException
Exception message: Error during serialization or deserialization using the JSON JavaScriptSerializer. The length of the string exceeds the value set on the maxJsonLength property.

Can I set an unlimited length for maxJsonLength in web.config? If not, what is the maximum length I can set?

Answer 1

You can set it in the config as others have said, or you can set in on an individual instance of the serializer like:

var js = new JavaScriptSerializer() { MaxJsonLength = int.MaxValue };

Answer 2

It appears that there is no "unlimited" value. The default is 2097152 characters, which is equivalent to 4 MB of Unicode string data.

As as already been observed, 17,000 records are hard to use well in the browser. If you are presenting an aggregate view it may be much more efficient to do the aggregation on the server and transfer only a summary in the browser. For example, consider a file system brower, we only see the top of the tree, then emit further requestes as we drill down. The number of records returned in each request is comparatively small. A tree view presentation can work well for large result sets.

Answer 3

Just ran into this. I'm getting over 6,000 records. Just decided I'd just do some paging. As in, I accept a page number in my MVC JsonResult endpoint, which is defaulted to 0 so it's not necessary, like so:

public JsonResult MyObjects(int pageNumber = 0)

Then instead of saying:

return Json(_repository.MyObjects.ToList(), JsonRequestBehavior.AllowGet);

I say:

return Json(_repository.MyObjects.OrderBy(obj => obj.ID).Skip(1000 * pageNumber).Take(1000).ToList(), JsonRequestBehavior.AllowGet);

It's very simple. Then, in JavaScript, instead of this:

function myAJAXCallback(items) {
    // Do stuff here
}

I instead say:

var pageNumber = 0;
function myAJAXCallback(items) {
    if(items.length == 1000)
        // Call same endpoint but add this to the end: '?pageNumber=' + ++pageNumber
    }
    // Do stuff here
}

And append your records to whatever you were doing with them in the first place. Or just wait until all the calls finish and cobble the results together.