LegacyMap
The LegacyMap
type can be used to represent a collection of key-value.
use starknet::ContractAddress;
#[starknet::interface]
trait IMappingExample<TContractState> {
fn register_user(ref self: TContractState, student_add: ContractAddress, studentName: felt252);
fn record_student_score(
ref self: TContractState, student_add: ContractAddress, subject: felt252, score: u16
);
fn view_student_name(self: @TContractState, student_add: ContractAddress) -> felt252;
fn view_student_score(
self: @TContractState, student_add: ContractAddress, subject: felt252
) -> u16;
}
#[starknet::contract]
mod MappingContract {
use starknet::ContractAddress;
#[storage]
struct Storage {
students_name: LegacyMap::<ContractAddress, felt252>,
students_result_record: LegacyMap::<(ContractAddress, felt252), u16>,
}
#[abi(embed_v0)]
impl External of super::IMappingExample<ContractState> {
fn register_user(
ref self: ContractState, student_add: ContractAddress, studentName: felt252
) {
self.students_name.write(student_add, studentName);
}
fn record_student_score(
ref self: ContractState, student_add: ContractAddress, subject: felt252, score: u16
) {
self.students_result_record.write((student_add, subject), score);
}
fn view_student_name(self: @ContractState, student_add: ContractAddress) -> felt252 {
self.students_name.read(student_add)
}
fn view_student_score(
self: @ContractState, student_add: ContractAddress, subject: felt252
) -> u16 {
// for a 2D mapping its important to take note of the amount of brackets being used.
self.students_result_record.read((student_add, subject))
}
}
}