JSON trouble serializing using .net Json

Question

Help a newb out please ... ;-x

I use jQuery to call .net WebAPI to make a Get call. The backend is SQL Server.

In the WebAPI, I use entity framework to call a stored procedure.

 var cat = ent.GetCategories();

 return Json.Encode(cat);

This fetches the data but back at the browser, the data looks like this and it doesn't plug into my dropdown. I'm guessing it has to do with the escape backslashes. How do I fix this?

"[\"Housing\",\"Jobs\",\"For Sale\",\"Community\",\"Services\"]"

score 0 · Answer 1 · edited May 23 '17 at 10:33

In jQuery.ajax() this too simplified. Try like below

jQuery.ajax({ 
    type: "GET"  //or POST,
    dataType: "json", 
    url: "your url",
    success: function(data) {   
        //data returns ["Housing","Jobs","For Sale","Community","Services"]
    }
});

For a simple and nice explanation,

By setting dataType: "json" you are telling jQuery to parse the received data as JSON, so data is delivered to the success() function as a Javascript array.

score 0 · Answer 2 · answered Nov 27 '13 at 15:44

0

The problem is that you are double-serializing the result. Web API does serialization for you so you do not need to call Json.Encode(). Instead just make your API controller method return cat.

answered Nov 27 '13 at 15:44

Brian Rogers

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originally, I did not encode and I returned cat. But on the browser side, I got error message: "ExceptionMessage":"The 'ObjectContent`1' type failed to serialize the response body for content type 'application/json;" ... so I tried to encode it like above. Then I didn't get the error msg but the returned now looked like above and I can't use the returned data in the callback like I normally would. Not sure if this matters, but I have my webAPI function as such: public dynamic Get(string filter) ... does the dynamic return type matter? – nanonerd Nov 28 '13 at 06:10
well, I tried something different and it works. But the call is super slow (4+ sec). In the webApi, I declare a List list. Using Entity Framework, I call the store proc and I run the returned object through a foreach loop. For each item found, I add it to the "list". Then I return "list" (without any direct json encoding). This works but it is super slow. Is this a bad method to get data using JQuery using the .net webAPI to access a store proc to get data from a SQL Server? – nanonerd Nov 28 '13 at 16:39
If you're returning a `List` from your API method then that is what you should declare as the return type of the method (`IEnumerable` should also work). I would not make the return type `dynamic` when the type is known. Serializing a short list of strings should not be slow in and of itself. I do this all the time in my Web API code with no problems at all. Are you sure the performance problem isn't in your stored procedure or something else you're doing? – Brian Rogers Nov 29 '13 at 01:53

Ilija Dimov · Answer 3 · 2013-11-28T21:54:20.017

If the data is returned like "[\"Housing\",\"Jobs\",\"For Sale\",\"Community\",\"Services\"]" what you can do before populating your dropdown is the following:

var escaped = "[\"Housing\",\"Jobs\",\"For Sale\",\"Community\",\"Services\"]";
var result = $("<div />").html(escaped).text();

After that the result will have the following value "["Housing","Jobs","For Sale","Community","Services"]".

Then you can call jQuery parse function to get a javascript array that you can populate to your dropdown:

var jsArr = $.parseJSON(result);

JSON trouble serializing using .net Json

3 Answers3