Can i make changes to the parameters defined in relationships - hyperledger-fabric

Question

1.i want to know whether i can make changes to the parmeter defined in the relationship.
what i want to do is to make a function with name of bookflight and then make changes to the number of seats if the flight is booked .
these are my cto files
namespace org.acme.airline.aircraft
/** Aircraft is an ACME Asset*/
asset Aircraft identified by aircraftId {
o String aircraftId
o Ownership ownershipType default="LEASED"
// Number of seats per class
o Integer firstClassSeats range = [4,]
o Integer businessClassSeats range = [6, 20]
o Integer economyClassSeats range = [30, ]
o String nickName optional
}
enum Ownership {
o LEASED
o OWNED
}
and for flight the code is
namespace org.acme.airline.flight
import org.acme.airline.aircraft.Aircraft
asset Flight identified by flightId {
// Solution to the exercise - try out the Regular expression at http://regex101.com
// Share your optimized regular expression with others :)
o String flightId regex=/[A-Z][A-Z][0-9][0-9][0-9]-[0-9][0-9]-[0-3][0-9]-[0-9][0-9]/
o String flightNumber
o Route route
o String[] aliasFlightNumber optional
--> Aircraft aircraft optional
}
concept Route {
o String origin regex=/[A-Z][A-Z][A-Z]/
o String destination regex=/[A-Z][A-Z][A-Z]/
o DateTime schedule
}
// Logistics department of ACME creates the flights
transaction CreateFlight {
o String flightNumber
o String origin
o String destination
o DateTime schedule
}
event FlightCreated {
o String flightId
}
// Assigns an aircraft to the flight
// The logistics / validation on availability of aircraft
// Kept outside of the Blockchain
transaction AssignAircraft {
o String flightId
o String aircraftId
}
// Event indicating that aircraft was assigned
event AircraftAssigned {
o String flightId
o String aircraftId
}
now what i want to make changes to reltionship in the flight
to make changes to it what should i do . i have made a javascript file.to
access make changes in it.
function booktickets(registry){
//array to recored the hold the instances of aircraft resourse
const bnDef = bnUtil.connection.getBusinessNetwork();
const factory = bnDef.getFactory();
let flightResource = factory.newResource(aircraftNamespace,aircraftType,'AE201-05-05-2020');
flightResource.setPropertyValue('flightNumber','AE101');
flightResource.route = factory.newConcept(aircraftNamespace,'Route');
flightResource.route.setPropertyValue('origin', 'DEL');
flightResource.route.setPropertyValue('destination' , 'APH');
flightResource.route.setPropertyValue('schedule' , new Date('2018-10-15T21:44Z'));
flightResource.aircraft = factory.newRelationship('org.acme.airline.aircraft', 'Aircraft', 'CRAFT01');
//.setPropertyValue()
flightResource.aircraft.setPropertyValue('ownershipType','LEASED');
flightResource.aircraft.setPropertyValue('firstClassSeats',10);
flightResource.aircraft.setPropertyValue('businessClassSeats',10);
flightResource.aircraft.setPropertyValue('economyClassSeats',100);
return registry.update(flightResource).then(()=>{
console.log('Successfully created the flight!!!');
bnUtil.disconnect();
}).catch((error)=>{
console.log(error);
bnUtil.disconnect();
});
}

Answer 1

your question appears to be: can you create a relationship from Flight (asset) to Aircraft (asset) in a transaction function (that operates in the chaincode runtime), and can you update the fields of the related Aircraft (in its separate registry). The answer is 'yes', you can, for both. You don't provide the model for the bookflight function, so can only make assumptions about its model definition. as a minimum (based on your code) it will need:
transaction bookflight { }
A code example of what you are trying to do with relationships - is shown here -> https://github.com/hyperledger/composer-sample-networks/blob/master/packages/perishable-network/lib/logic.js#L130
This section:
const bnDef = bnUtil.connection.getBusinessNetwork();
const factory = bnDef.getFactory();
is composer-client code - and will not work inside a transaction function (that is runtime code, you need to remove client code - the example below shows 'how' to do it.) Replace line 2 with :
const factory = getFactory();
See more on transaction functions, examples etc at https://hyperledger.github.io/composer/latest/reference/js_scripts
note: you can just assign values like:
flightResource.route.origin = 'DEL' ; // no need for.setPropertyValue('origin', 'DEL'); etc etc
I don't see your code to update the Aircraft registry (with flightResource.aircraft FYI) - but you would need that to update the fields in that related asset (presently, you're only updating the Flight registry above )
new Date() is non deterministic code - if you're hoping to achieve consensus from multiple peers/orgs.
You'll notice the link I sent earlier, shows the use of async/await rather than JS promises (.then etc etc) - easier to code, easier to read. cheers.