Question

I am trying to send a model as json. The model has binary data in one of it’s columns. For another model I have used

format.json {self.encode64(@resource_type.data).to_json}

with success, but in that case I only wanted the data column, and not the title etc. What can I do when I want contents from several columns, where only one column’s content should be encoded with encode64?

In the following code, I don’t know where to put the self.encode64 method.

format.json { render :json => @resource.to_json(:only => [:id, :title, :data])}

How can I do this?

Answer 1

You have a few options here.

You could add a data_base64 method to your model that returned the data in base-64 format and then use the :methods option to to_json in your controller:

@resource.to_json(:only => [ :id, :title ], :methods => :data_base64)

That would give you a data_base64 key in the JSON instead of data but that might not be a problem.

You could also use as_json to get a hash and fix the encoding in the controller:

json = @resource.as_json(:only => [ :id, :title, :data ])
json['resource']['data'] = self.encode64(json['resource']['data'])
render :json => json