feat: enhance JSON parsing in ServiceProjectAllocationResponse and related models to handle null values gracefully

lib/model/service_project/job_allocation_model.dart

@@ -15,16 +15,26 @@ class ServiceProjectAllocationResponse {
     required this.timestamp,
   });
 
-  factory ServiceProjectAllocationResponse.fromJson(Map<String, dynamic> json) {
+  factory ServiceProjectAllocationResponse.fromJson(Map<String, dynamic>? json) {
+    if (json == null) {
+      return ServiceProjectAllocationResponse(
+        success: false,
+        message: "",
+        data: [],
+        statusCode: 0,
+        timestamp: DateTime.now(),
+      );
+    }
+
     return ServiceProjectAllocationResponse(
-      success: json['success'] as bool,
-      message: json['message'] as String,
-      data: (json['data'] as List<dynamic>)
+      success: json['success'] as bool? ?? false,
+      message: json['message'] as String? ?? "",
+      data: (json['data'] as List<dynamic>? ?? [])
           .map((e) => ServiceProjectAllocation.fromJson(e))
           .toList(),
       errors: json['errors'],
-      statusCode: json['statusCode'] as int,
-      timestamp: DateTime.parse(json['timestamp'] as String),
+      statusCode: json['statusCode'] as int? ?? 0,
+      timestamp: DateTime.tryParse(json['timestamp'] ?? "") ?? DateTime.now(),
     );
   }
 
@@ -61,17 +71,30 @@ class ServiceProjectAllocation {
     this.reAssignedBy,
   });
 
-  factory ServiceProjectAllocation.fromJson(Map<String, dynamic> json) {
+  factory ServiceProjectAllocation.fromJson(Map<String, dynamic>? json) {
+    if (json == null) {
+      return ServiceProjectAllocation(
+        id: "",
+        project: Project.fromJson(null),
+        employee: Employee.fromJson(null),
+        teamRole: TeamRole.fromJson(null),
+        isActive: false,
+        assignedAt: DateTime.now(),
+        assignedBy: Employee.fromJson(null),
+      );
+    }
+
     return ServiceProjectAllocation(
-      id: json['id'] as String,
+      id: json['id'] as String? ?? "",
       project: Project.fromJson(json['project']),
       employee: Employee.fromJson(json['employee']),
       teamRole: TeamRole.fromJson(json['teamRole']),
-      isActive: json['isActive'] as bool,
-      assignedAt: DateTime.parse(json['assignedAt'] as String),
+      isActive: json['isActive'] as bool? ?? false,
+      assignedAt:
+          DateTime.tryParse(json['assignedAt'] ?? "") ?? DateTime.now(),
       assignedBy: Employee.fromJson(json['assignedBy']),
       reAssignedAt: json['reAssignedAt'] != null
-          ? DateTime.parse(json['reAssignedAt'])
+          ? DateTime.tryParse(json['reAssignedAt']) ?? DateTime.now()
           : null,
       reAssignedBy: json['reAssignedBy'] != null
           ? Employee.fromJson(json['reAssignedBy'])
@@ -111,15 +134,28 @@ class Project {
     required this.contactEmail,
   });
 
-  factory Project.fromJson(Map<String, dynamic> json) {
+  factory Project.fromJson(Map<String, dynamic>? json) {
+    if (json == null) {
+      return Project(
+        id: "",
+        name: "",
+        shortName: "",
+        assignedDate: DateTime.now(),
+        contactName: "",
+        contactPhone: "",
+        contactEmail: "",
+      );
+    }
+
     return Project(
-      id: json['id'] as String,
-      name: json['name'] as String,
-      shortName: json['shortName'] as String,
-      assignedDate: DateTime.parse(json['assignedDate'] as String),
-      contactName: json['contactName'] as String,
-      contactPhone: json['contactPhone'] as String,
-      contactEmail: json['contactEmail'] as String,
+      id: json['id'] as String? ?? "",
+      name: json['name'] as String? ?? "",
+      shortName: json['shortName'] as String? ?? "",
+      assignedDate:
+          DateTime.tryParse(json['assignedDate'] ?? "") ?? DateTime.now(),
+      contactName: json['contactName'] as String? ?? "",
+      contactPhone: json['contactPhone'] as String? ?? "",
+      contactEmail: json['contactEmail'] as String? ?? "",
     );
   }
 
@@ -153,15 +189,27 @@ class Employee {
     required this.jobRoleName,
   });
 
-  factory Employee.fromJson(Map<String, dynamic> json) {
+  factory Employee.fromJson(Map<String, dynamic>? json) {
+    if (json == null) {
+      return Employee(
+        id: "",
+        firstName: "",
+        lastName: "",
+        email: null,
+        photo: null,
+        jobRoleId: "",
+        jobRoleName: "",
+      );
+    }
+
     return Employee(
-      id: json['id'] as String,
-      firstName: json['firstName'] as String,
-      lastName: json['lastName'] as String,
+      id: json['id'] as String? ?? "",
+      firstName: json['firstName'] as String? ?? "",
+      lastName: json['lastName'] as String? ?? "",
       email: json['email'] as String?,
       photo: json['photo'] as String?,
-      jobRoleId: json['jobRoleId'] as String,
-      jobRoleName: json['jobRoleName'] as String,
+      jobRoleId: json['jobRoleId'] as String? ?? "",
+      jobRoleName: json['jobRoleName'] as String? ?? "",
     );
   }
 
@@ -187,11 +235,19 @@ class TeamRole {
     required this.description,
   });
 
-  factory TeamRole.fromJson(Map<String, dynamic> json) {
+  factory TeamRole.fromJson(Map<String, dynamic>? json) {
+    if (json == null) {
+      return TeamRole(
+        id: "",
+        name: "",
+        description: "",
+      );
+    }
+
     return TeamRole(
-      id: json['id'] as String,
-      name: json['name'] as String,
-      description: json['description'] as String,
+      id: json['id'] as String? ?? "",
+      name: json['name'] as String? ?? "",
+      description: json['description'] as String? ?? "",
     );
   }