Hyperledger How to update values from an asset

Question

I want to find the rider_id and update parcel_id in the following. 

model

asset Route identified by route_id {
  o String route_id
  o String rider_id
  o String parcel_id
}
transaction assignParcelToRider {
  o String rider_id
  o String parcel_id
}

logic.js

var assetRegistry;
var id = assignValue.rider_id;
return getAssetRegistry('org.rytle.Route').then(function(ar) {
    assetRegistry = ar;
    return assetRegistry.get(id);
}).then(function(asset) {
    asset.parcel_id = assignValue.parcel_id;
    return assetRegistry.update(asset);
});

Here I want to find the rider_id and update parcel_id there. But here its not finding t

model

asset Route identified by route_id {
  o String route_id
  o String rider_id
  o String parcel_id
}
transaction assignParcelToRider {
  o String rider_id
  o String parcel_id
}

logic.js

var assetRegistry;
var id = assignValue.rider_id;
return getAssetRegistry('org.rytle.Route').then(function(ar) {
    assetRegistry = ar;
    return assetRegistry.get(id);
}).then(function(asset) {
    asset.parcel_id = assignValue.parcel_id;
    return assetRegistry.update(asset);
});

Answer 1

This should work:

return getAssetRegistry('org.rytle.Route').then(function(ar) {
      return ar.get(route_id)   // or whatever you've assigned it to or txnobject.route.getIdentifier());   // ie you must get the asset by identifier
      }).then(function(asset) {
           asset.parcel_id = id;   
           return ar.update(asset);
       });