This is my OnAppearingAsync method where I as a page load in Xamarin I filter data, group it together, set data based on it, order the groups e.t.c. However the code is rather long and looks a bit messy, I've tried to refactor it myself but I always get stuck on where I'm supposed to start.
How can I improve this? Everything works beautifully and efficiently as far I know, I just believe it would never pass any code review in current status (We don't have code review though)
public async Task OnAppearingAsync(string houseCode) { HouseCode = houseCode; var client = AppClientHelper.Get(); var groupHolders = new ObservableCollection<SubBrandGroup>(); // Get The Groups List<SubBrandViewModel> subBrandViewModels = client.GetSubBrandViewModels(HouseCode); // Filter the subBrands var filteredSubBrands = subBrandViewModels.Where(item => CurrentCustomerCardViewModel.AllowedCategories.AllowedSubBrands.Contains(item.Code)).ToList(); foreach (var subBrandViewModel in filteredSubBrands) { var basicItems = client.GetBaiscItemViewModelsBySubGroup(subBrandViewModel.HouseCode, subBrandViewModel.Code); // Apply the proper price, unique customer values e.t.c foreach (var basicItem in basicItems) { basicItem.PropertyChanged += OnOrderCountUpdate; await SetUniqueBrandStatusBrandStatus(basicItem); } // Order Item in SubGroup by alphabetical order var sortedItems = basicItems.OrderBy(item => item.Description).ToList(); SubBrandGroup subBrand = new SubBrandGroup(subBrandViewModel.Name, true, subBrandViewModel.AdditionalCollateralItem, sortedItems); // Add group if not empty if (subBrand.Count != 0) { groupHolders.Add(subBrand); } Currency = basicItems.FirstOrDefault()?.Currency; } if (groupHolders.Count == 0) return; // Order the groups int[] map = { 0, 2, 5, 3, 1, 4 }; // Sort the group var sortedGroups = groupHolders.OrderBy(x => map[(int)x.AdditionalCollateralItem]).ToList(); // Assign the new sorted items to the list ProductList = new ObservableCollection<SubBrandGroup>(sortedGroups); } 
