检索POST JSON响应

Question

I'm writing my first Ajax request, on a Groovy/Grails platform.

    var newDataB = $.ajax({
    method:'post',
    url: url,
    async: false,
    data: {source:"${source}"},
    success: function (response) { 
        jsonData = response;
        var res = JSON.parse(jsonData);
                alert(res);//
    }
});

Here is the response of my controller "url"

    def result = [ value: 'ok' ]
    render result as JSON

But it does not work and i get an error message in my browser

SyntaxError: JSON.parse: unexpected character at line 1 column 2 of the JSON data 
var res = JSON.parse(jsonData);

I don't understand , the response seems to be a nice formatted JSON ?

EDIT i did a print as Paul suggests :

If i execute

    var newDataB = $.ajax({
    method:'post',
    url: url,
    async: false,
    dataType: 'json',
    data: {source:"${source}"},
    success: function (response) { 
        console.log(response)
        console.log(response.value)
        jsonData = response;
    }
});

The first print is :

Object { value="ok"}

The second print is

ok

If i want to get the result, how is the proper way ?

Do i have to assign the value inside the statement "success: function (response) { "

doing something like

var result

var newDataB = $.ajax({
    method:'post',
    url: url,
    async: false,
    dataType: 'json',
    data: {source:"${source}"},
    success: function (response) { 
    result = response.value
    }
});

console.log("result : "+result);

This code works for me !!

Or perhaps there is a way to get the result, doing something like

var newDataB = $.ajax({
    method:'post',
    url: url,
    async: false,
    dataType: 'json',
    data: {source:"${source}"},
    success: function (response) { 

    }
});

var result = newDataB.response.somethingblablabla

or

var result = OneFunction(newDataB.response)

??????

Answer 1

You shouldn't need to parse it, if your server is providing json.

You can use dataType though to force jQuery to use a particular type:

var newDataB = $.ajax({
    method:'post',
    url: url,
    async: false,
    dataType: 'json',
    data: {source:"${source}"},
    success: function (response) { 
        console.log(response);

    }
});