ember-data: server side code for removing an associated object - ruby-on-rails

Question

I 'm working with revision 12 of ember-data RESTAdapter and using the rails-api gem.
I have these models:
App.TransportDocumentRow = DS.Model.extend,
productName: DS.attr 'string'
transportDocument: DS.belongsTo('App.TransportDocument')
App.TransportDocument = DS.Model.extend
number: DS.attr 'string'
transportDocumentRows: DS.hasMany('App.TransportDocumentRow')
configured in this way:
DS.RESTAdapter.map 'App.TransportDocument', {
transportDocumentRows: { embedded: 'always' }
}
(i'm using embedded: always becauseif i don't my document rows are committed with document_id = 0, as asked here
Consider i have already created a transport document (id: 1) with 2 rows. If i delete a row (with id: 1), the result would be a PUT request to /transport_documents/1.
The JSON sent with this put would be something like this:
{"transport_document"=>
{"number"=>"1", "transport_document_rows"=>
[
{"id"=>2, "product_name"=>"aaaa", "transport_document_id"=>1}
]
}, "id"=>"1"
}
while rails would expect something like this:
{"transport_document"=>
{"number"=>"1", "transport_document_rows"=>
[
{"id"=>1, "_delete"=>1}
{"id"=>2, "product_name"=>"aaaa", "transport_document_id"=>1}
]
}, "id"=>"1"
}
Is there a way specified in active_model_serializers to do this?
Or should i make some manual transformations my controller?
Or should i change the payload so that ember produces the correct request?