[Dancer-users] to_json not JSON-ifying the entire variable

Mon Oct 11 06:49:52 CEST 2010

On Sun, Oct 10, 2010 at 11:18 PM, P Kishor <punk.kish at gmail.com> wrote:
> On Thu, Oct 7, 2010 at 5:03 PM, P Kishor <punk.kish at gmail.com> wrote:
>> I have a data object in JavaScript that I am JSONifying, sending to
>> the server (using jQuery ajax) and storing in a SQLite table. In
>> SQLite, the values look like so (I have prettified it by adding
>> returns and tabs)
>>
>> [
>>    {
>>        "a":{"aa":0,"ab":448960000,"ac":"140075520.00"},
>>        "b":1,
>>        "c":"foo"
>>    }
>> ]
>>
>> I retrieve it via ajax again, and use Dancer's to_json method to send
>> the result back. In Firebug, it shows up as
>>
>> [
>>    {
>>        "a":"{\"aa\":0,\"ab\":448960000,\"ac\":\"140075520.00\"}",
>>        "b":1,
>>        "c":"foo"
>>    }
>> ]
>>
>> In other words, to_json seems to stringify all 2nd-level and deeper
>> values. As a result, while the entire value is returned as a JSON
>> object, its internal parts are recognized as strings. That doesn't
>> seem right, no? Its like drinking a cup of coffee, but three sips in
>> finding it to be hot chocolate.
>>
>> I can get around it by reparsing the strings as JSON, but it really
>> shouldn't be so. The data are stored in the SQLite table as a string,
>> so to_json should JSON-ify it all the way through, and send it back as
>> a fully-formed JSON object.
>>
>
>
> The above is really proving to be a bit of a headache for me. Because
> to_json is escaping the quotes in the variable, I am not able to
> reconstruct the JSON object back in my browser. I am using the json
> converter from http://www.json.org/json2.js to convert, but I am
> getting a "syntax error" when I try to use `JSON.parse(data)` where
> data has been retrieved by the browser.
>
> Any suggestions.
>
> --
> Puneet Kishor
> _______________________________________________
> Dancer-users mailing list
> Dancer-users at perldancer.org
> http://www.backup-manager.org/cgi-bin/listinfo/dancer-users
>

I have written this simple dancer app which works fine:

#!/usr/bin/env perl
use Dancer;

get '/' => sub {
    return q[
    <html>
    <head>
    <script>
    function foo() {
        var x = new XMLHttpRequest();
        x.open("GET", "/foo", false);
        x.send();
        alert(x.responseText);
    }
    </script>
    </head>
    <body>
    <input type="button" value="Go" onclick="foo()" />
    </body>
    </html>
    ];
};

get '/foo' => sub {
    return q[
    {
        "a": {"aa":0,"ab":448960000,"ac":"140075520.00"},
        "b": 1,
        "c": "foo"
    }
    ];
};

dance;

The problem I think you are having is that you are calling to_json on
a json string.  You are serializing something that is already
serialized.  Just return what is in your sqlite database without
calling to_json on it.

-Naveed