JSON render problem

Rails
1

Hi all,

In my controller, I have an action to render JSON string containing
current user’s account information, except for his ID and hashed
password. This is the snippet:

Fetch the account information of the current user

def fetch_data

record = User.find session[:user_id]

render :json =>
{
:success => true,
:data => (record.to_json(:except => [:id, :password]))
}
end

It does not work. The :data attribute contains a JSON string instead of
an object.
Sample output:

{“success”:true,“data”:"{“name”:“The
Administrator”,“username”:“admin”,“role”:“admin”}"}

How can I fix this?

Thanks.

2

-=

On Sun, Jan 24, 2010 at 9:24 PM, Andree S. [email protected]
wrote:

First, the above statement returns an instance of User,

{“success”:true,“data”:“{"name":"The
Administrator","username":"admin","role":"admin"}”}

How can I fix this?

The above seems correct based on your render statement. What’s the
problem?

-Conrad

3

On Sun, Jan 24, 2010 at 10:10 PM, Andree S. [email protected]
wrote:

Conrad T. wrote:

The above seems correct based on your render statement. What’s the
problem?

-Conrad

The data attribute should be an object, not a string.
Let’s compare the difference with the following snippet:

From the JSON specification, http://www.json.org/, an object in JSON
consists of name/value pairs. The object here is “data” and you should
be
able to easily access
this information on the client side.

Next, you can limit which fields get returned from a SQL query using
‘find(:all, :select => “arg1, arg2, …”, … )’.

Finally, the easiest way to convert an AR instance to JSON is to use
to_json
method on the instance (i.e. object.to_json). Otherwise, you can write a
simply method, to_hash or to_h, which returns the hash of the AR. Then
you’ll have something like this:

def to_hash
{ :name => self.name, :username => self.username, :role => self.role }
end

render :json => { :success => true, :data => record.to_hash }

Good luck,

-Conrad

4

Conrad T. wrote:

The above seems correct based on your render statement. What’s the
problem?

-Conrad

The data attribute should be an object, not a string.
Let’s compare the difference with the following snippet:

render :json =>
{
:success => true,
:data => record # Without to_json method
}

The output will be: (the data attribute is an object)
{“success”:true,“data”:{“name”:“The
Administrator”,“username”:“admin”,“role”:“admin”,“id”:1,“password”:“d033e22ae348aeb5660fc2140aec35850c4da997”}}

Instead of: (the data attribute is a string)
{“success”:true,“data”:"{“name”:“The
Administrator”,“username”:“admin”,“role”:“admin”}"}

The problem is, I want to hide several attributes from the output, and
the only method that I know is to use :except parameter from to_json
method.

So, my objective is to get the output similiar to output #1, but without
the ID and password attribute.