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Example 06: Advanced Search and Filtering Implementation

Overview​

The dashboard implements sophisticated search and filtering capabilities that allow users to quickly find specific inventory items across multiple criteria including warehouse, supplier, stock code, and custom attributes.

Search Implementation​

// WarehouseOrderingViewModel.cs - Search implementation
public IQueryable<WarehouseOrderingListItem> GetFilteredData(
    WarehouseSearchFilter filter)
{
    var query = _context.CG_InventoryOrdering_View.AsQueryable();
    
    // Text search across multiple fields
    if (!string.IsNullOrWhiteSpace(filter.SearchString))
    {
        var search = filter.SearchString.ToUpper();
        query = query.Where(x =>
            x.Warehouse.ToUpper().Contains(search) ||
            x.WarehouseDescription.ToUpper().Contains(search) ||
            x.Supplier.ToUpper().Contains(search) ||
            x.SupplierName.ToUpper().Contains(search) ||
            x.StockCode.ToUpper().Contains(search) ||
            x.StockDescription.ToUpper().Contains(search));
    }
    
    // Warehouse filter
    if (filter.SelectedWarehouse != null)
    {
        query = query.Where(x => x.Warehouse == filter.SelectedWarehouse.Warehouse);
    }
    
    // Supplier filter
    if (!string.IsNullOrWhiteSpace(filter.SelectedSupplier))
    {
        query = query.Where(x => x.Supplier == filter.SelectedSupplier);
    }
    
    // Stock status filter
    if (!filter.ShowStockOnHold)
    {
        query = query.Where(x => x.StockOnHold != "Y");
    }
    
    // Quantity filters
    if (filter.ShowOnlyBelowSafetyStock)
    {
        query = query.Where(x => x.QtyOnHand < x.SafetyQty);
    }
    
    return query.OrderBy(x => x.Warehouse).ThenBy(x => x.StockCode);
}

Supplier Selection Dialog​

Advanced supplier search with paging:

// SupplierSelectionViewModel.cs
public IQueryable<SupplierSelectionListItem> GetQueryable()
{
    var queryable = from s in _context.ApSupplier
                    join ad in _context.ApSupplierAddr on s.Supplier equals ad.Supplier
                    join b in _context.ApBank on s.Bank equals b.Bank into bankJoin
                    from bank in bankJoin.DefaultIfEmpty()
                    select new SupplierSelectionListItem
                    {
                        Supplier = s.Supplier,
                        SupplierName = s.SupplierName,
                        Bank = s.Bank,
                        BankDescription = bank?.Description ?? "",
                        CurrentBalance = s.CurrentBalance ?? 0,
                        Address1 = ad.SupAddr1,
                        // ... additional fields
                    };

    if (!string.IsNullOrEmpty(SearchString))
    {
        var search = SearchString.ToUpper();
        queryable = queryable.Where(x =>
            x.Supplier.ToUpper().Contains(search) ||
            x.SupplierName.ToUpper().Contains(search) ||
            x.Address1.ToUpper().Contains(search) ||
            x.PostalCode.ToUpper().Contains(search));
    }

    return queryable.OrderBy(x => x.Supplier);
}

Performance Optimizations​

Database indexes for search performance:

CREATE INDEX IX_Inventory_Search 
ON CG_InventoryOrdering_View(Warehouse, Supplier, StockCode)

CREATE INDEX IX_Supplier_Search
ON ApSupplier(Supplier, SupplierName)
INCLUDE (OnHold, Currency)

Prevent excessive queries during typing:

public class DebouncedSearch
{
    private Timer _debounceTimer;
    private readonly int _debounceMs = 300;
    
    public void Search(string searchText)
    {
        _debounceTimer?.Dispose();
        _debounceTimer = new Timer(_ =>
        {
            Application.Current.Dispatcher.Invoke(() =>
            {
                ExecuteSearch(searchText);
            });
        }, null, _debounceMs, Timeout.Infinite);
    }
}

Advanced Features​

Search History​

public class SearchHistoryService
{
    private readonly List<string> _recentSearches = new();
    private const int MaxHistory = 10;
    
    public void AddToHistory(string search)
    {
        _recentSearches.Remove(search);
        _recentSearches.Insert(0, search);
        
        if (_recentSearches.Count > MaxHistory)
            _recentSearches.RemoveAt(MaxHistory);
            
        SaveHistory();
    }
    
    public IEnumerable<string> GetSuggestions(string partial)
    {
        return _recentSearches
            .Where(s => s.StartsWith(partial, StringComparison.OrdinalIgnoreCase))
            .Take(5);
    }
}

Filter Persistence​

Save and restore user filter preferences:

public void SaveFilterPreferences(WarehouseSearchFilter filter)
{
    var json = JsonConvert.SerializeObject(filter);
    _mepSettingsService.SetByOperatorAsync("LastSearchFilter", json);
}

public WarehouseSearchFilter LoadFilterPreferences()
{
    var json = _mepSettingsService.Get("LastSearchFilter");
    return string.IsNullOrEmpty(json) 
        ? new WarehouseSearchFilter() 
        : JsonConvert.DeserializeObject<WarehouseSearchFilter>(json);
}

Benefits​

  • Fast item location
  • Reduced data entry errors
  • Improved user productivity
  • Flexible search criteria
  • Performance optimization