feat: replaced students mapping with a vector

src/student_registry.cairo

@@ -9,11 +9,18 @@ pub trait IStudentRegistry<T> {
     ) -> bool;
 
     // read-only function to get student
-    fn get_student(self: @T, account: ContractAddress) -> (felt252, ContractAddress, u8, u16, bool);
+    fn get_student(self: @T, student_id: u64) -> (u64, felt252, ContractAddress, u8, u16, bool);
     // fn get_all_students(self: @T) -> Span<Student>;
     fn get_all_students(self: @T) -> Span<Student>;
+    // state-change function to update student data
     fn update_student(
-        ref self: T, _name: felt252, _account: ContractAddress, _age: u8, _xp: u16, _is_active: bool
+        ref self: T,
+        _id: u64,
+        _name: felt252,
+        _account: ContractAddress,
+        _age: u8,
+        _xp: u16,
+        _is_active: bool
     ) -> bool;
 }
 
@@ -25,18 +32,14 @@ pub mod StudentRegistry {
     use core::num::traits::Zero;
 
     use starknet::storage::{
-        StoragePointerReadAccess, StoragePointerWriteAccess, Vec, VecTrait, MutableVecTrait,
-        StoragePathEntry, Map
+        StoragePointerReadAccess, StoragePointerWriteAccess, Vec, VecTrait, MutableVecTrait
     };
     use crate::errors::Errors;
 
     #[storage]
     struct Storage {
         admin: ContractAddress,
-        students_map: Map::<ContractAddress, Student>,
-        students_vector: Vec<ContractAddress>,
-        students_index: Map::<u64, ContractAddress>,
-        total_no_of_students: u64
+        students_vector: Vec<Student>
     }
 
 
@@ -60,58 +63,50 @@ pub mod StudentRegistry {
         ) -> bool {
             // validation to check if student account is valid address and  not a 0 address
             assert(!self.is_zero_address(_account), Errors::ZERO_ADDRESS);
+            // validate student age
             assert(_age > 0, 'age cannot be 0');
+
+            // set student vector length as new student Id
+            let _id = self.students_vector.len();
             let student = Student {
-                name: _name, account: _account, age: _age, xp: _xp, is_active: _is_active
+                id: _id, name: _name, account: _account, age: _age, xp: _xp, is_active: _is_active
             };
 
-            // add new student to storage
-            self.students_map.entry(_account).write(student);
-
-            // keep track of student's account address
-            self.students_vector.append().write(_account);
-
-            // keep track of the student index
-            self.students_index.entry(self.total_no_of_students.read()).write(_account);
-
-            // increase student's count
-            self.total_no_of_students.write(self.total_no_of_students.read() + 1);
+            // append student data to the students vector
+            self.students_vector.append().write(student);
 
             true
         }
 
         // read-only function to get student
         fn get_student(
-            self: @ContractState, account: ContractAddress
-        ) -> (felt252, ContractAddress, u8, u16, bool) {
+            self: @ContractState, student_id: u64
+        ) -> (u64, felt252, ContractAddress, u8, u16, bool) {
             // validation to check if account is valid
-            assert(!self.is_zero_address(account), Errors::ZERO_ADDRESS);
-            let student = self.students_map.entry(account).read();
-            (student.name, student.account, student.age, student.xp, student.is_active)
+            assert(student_id > 0, 'id cannot < 0');
+            let student = self.students_vector.at(student_id).read();
+            (student.id, student.name, student.account, student.age, student.xp, student.is_active)
         }
 
         fn get_all_students(self: @ContractState) -> Span<Student> {
             // empty array to store students
             let mut all_students: Array<Student> = array![];
 
-            // loop through the students vector containing the accounts of the student and use the
-            // account to get and return the student details
+            // loop through the students vector and append each student data to the students array
             for i in 0
                 ..self
                     .students_vector
                     .len() {
                         // append each student details to the students array
-                        all_students
-                            .append(
-                                self.students_map.entry(self.students_vector.at(i).read()).read()
-                            );
+                        all_students.append(self.students_vector.at(i).read());
                     };
 
             all_students.span()
         }
 
         fn update_student(
             ref self: ContractState,
+            _id: u64,
             _name: felt252,
             _account: ContractAddress,
             _age: u8,
@@ -120,14 +115,13 @@ pub mod StudentRegistry {
         ) -> bool {
             // validation to check if account is valid
             assert(!self.is_zero_address(_account), Errors::ZERO_ADDRESS);
-            let old_student: Student = self.students_map.entry(_account).read();
-            // validation to check if student exist
-            assert(old_student.age > 0, Errors::STUDENT_NOT_REGISTERED);
+            let mut student_pointer = self.students_vector.at(_id);
             let new_student = Student {
-                name: _name, account: _account, age: _age, xp: _xp, is_active: _is_active
+                id: _id, name: _name, account: _account, age: _age, xp: _xp, is_active: _is_active
             };
-            // update student info
-            self.students_map.entry(_account).write(new_student);
+
+            // update student data
+            student_pointer.write(new_student);
 
             true
         }

src/student_struct.cairo

@@ -1,6 +1,7 @@
 use starknet::ContractAddress;
 #[derive(Drop, Serde, starknet::Store)]
 pub struct Student {
+    pub id: u64,
     pub name: felt252,
     pub account: ContractAddress,
     pub age: u8,