feat: Add multi-column search

Author: DerekGooding

SimpleDataGrid.Example/MainViewModel.cs

@@ -9,6 +9,10 @@ public class MainViewModel
     public PagedCollection<Person> People { get; }
     public List<int> PageSizes { get; } = [10, 25, 50, 100];
 
+    public bool SearchByName { get; set; } = true;
+    public bool SearchByEmail { get; set; } = false;
+    public bool SearchByDepartment { get; set; } = false;
+
     public MainViewModel()
     {
         People = new PagedCollection<Person>(10);
@@ -20,7 +24,7 @@ private static List<Person> GetPeople()
         var people = new List<Person>();
         for (var i = 1; i <= 100; i++)
         {
-            people.Add(new Person { Id = i, Name = $"Person {i}", Age = 20 + (i % 50) });
+            people.Add(new Person { Id = i, Name = $"Person {i}", Age = 20 + (i % 50), Email = $"person{i}@example.com", Department = (i % 2 == 0) ? "Sales" : "Marketing" });
         }
         return people;
     }
@@ -58,4 +62,6 @@ public class Person
     public int Id { get; set; }
     public string Name { get; set; } = string.Empty;
     public int Age { get; set; }
+    public string Email { get; set; } = string.Empty;
+    public string Department { get; set; } = string.Empty;
 }

SimpleDataGrid.Example/MainWindow.xaml

@@ -29,6 +29,12 @@
                 <CheckBox x:Name="WildcardCheckBox" Content="Use Wildcards" VerticalAlignment="Center" Margin="5" />
                 <ProgressBar IsIndeterminate="True" Width="20" Height="20" Margin="5" Visibility="{Binding People.IsSearching, Converter={StaticResource BooleanToVisibilityConverter}}"/>
             </StackPanel>
+            <StackPanel Orientation="Horizontal" Margin="5,0,0,0">
+                <TextBlock Text="Search In:" VerticalAlignment="Center" Margin="0,0,5,0"/>
+                <CheckBox Content="Name" IsChecked="{Binding SearchByName}" Checked="SearchOption_Changed" Unchecked="SearchOption_Changed" Margin="0,0,5,0"/>
+                <CheckBox Content="Email" IsChecked="{Binding SearchByEmail}" Checked="SearchOption_Changed" Unchecked="SearchOption_Changed" Margin="0,0,5,0"/>
+                <CheckBox Content="Department" IsChecked="{Binding SearchByDepartment}" Checked="SearchOption_Changed" Unchecked="SearchOption_Changed" Margin="0,0,5,0"/>
+            </StackPanel>
             <StackPanel Orientation="Horizontal">
                 <TextBox x:Name="MinAgeTextBox" Width="50" Margin="5" />
                 <Button Content="Filter by Min Age" Click="FilterButton_Click" Margin="5" />

SimpleDataGrid.Example/MainWindow.xaml.cs

@@ -21,9 +21,25 @@ private void NextButton_Click(object sender, RoutedEventArgs e)
     }
 
     private void SearchTextBox_TextChanged(object sender, TextChangedEventArgs e)
+    {
+        ApplyMultiColumnSearch();
+    }
+
+    private void SearchOption_Changed(object sender, RoutedEventArgs e)
+    {
+        ApplyMultiColumnSearch();
+    }
+
+    private void ApplyMultiColumnSearch()
     {
         var viewModel = (MainViewModel)DataContext;
-        viewModel.People.SetSearch(p => p.Name, SearchTextBox.Text, WildcardCheckBox.IsChecked == true, 300);
+        var selectors = new List<Func<Person, string>>();
+
+        if (viewModel.SearchByName) selectors.Add(p => p.Name);
+        if (viewModel.SearchByEmail) selectors.Add(p => p.Email);
+        if (viewModel.SearchByDepartment) selectors.Add(p => p.Department);
+
+        viewModel.People.SetSearch(selectors, SearchTextBox.Text, WildcardCheckBox.IsChecked == true, 300);
     }
 
     private void FilterButton_Click(object sender, RoutedEventArgs e)

SimpleDataGrid/Pagination/PagedCollection.cs

@@ -31,7 +31,7 @@ public int PageSize
 
     private readonly Dictionary<string, Func<T, bool>> _filters = [];
     private readonly List<(Func<T, object> selector, bool ascending)> _sorts = [];
-    private Func<T, string>? _searchSelector;
+    private IEnumerable<Func<T, string>> _searchSelectors = [];
     private string? _searchTerm;
     private bool _useWildcards;
     private System.Threading.Timer? _debounceTimer;
@@ -164,7 +164,49 @@ public void ClearFilters()
     /// <param name="debounceMilliseconds">Optional. The number of milliseconds to debounce the search. If 0, no debouncing occurs.</param>
     public void SetSearch(Func<T, string> selector, string? term, bool useWildcards = false, int debounceMilliseconds = 0)
     {
-        _searchSelector = selector;
+        SetSearch([selector], term, useWildcards, debounceMilliseconds);
+    }
+
+    /// <summary>
+    /// Sets the search criteria for the collection, searching across multiple properties.
+    /// </summary>
+    /// <param name="selectors">A collection of functions that return the string representation of the properties to search.</param>
+    /// <param name="term">The search term.</param>
+    /// <param name="useWildcards">A value indicating whether to use wildcards in the search term.</param>
+    /// <param name="debounceMilliseconds">Optional. The number of milliseconds to debounce the search. If 0, no debouncing occurs.</param>
+    public void SetSearch(IEnumerable<Func<T, string>> selectors, string? term, bool useWildcards = false, int debounceMilliseconds = 0)
+    {
+        _searchSelectors = selectors ?? throw new ArgumentNullException(nameof(selectors));
+        _searchTerm = term;
+        _useWildcards = useWildcards;
+
+        if (debounceMilliseconds > 0)
+        {
+            IsSearching = true;
+            _debounceTimer?.Dispose();
+            _debounceTimer = new System.Threading.Timer(_ =>
+            {
+                System.Windows.Application.Current.Dispatcher.Invoke(ApplyFiltering);
+                IsSearching = false;
+            }, null, debounceMilliseconds, System.Threading.Timeout.Infinite);
+        }
+        else
+        {
+            ApplyFiltering();
+            SearchChanged?.Invoke(this, EventArgs.Empty);
+        }
+    }
+
+    /// <summary>
+    /// Sets the search criteria for the collection, requiring all selectors to match the term.
+    /// </summary>
+    /// <param name="selectors">A collection of functions that return the string representation of the properties to search.</param>
+    /// <param name="term">The search term.</param>
+    /// <param name="useWildcards">A value indicating whether to use wildcards in the search term.</param>
+    /// <param name="debounceMilliseconds">Optional. The number of milliseconds to debounce the search. If 0, no debouncing occurs.</param>
+    public void SetSearchAll(IEnumerable<Func<T, string>> selectors, string? term, bool useWildcards = false, int debounceMilliseconds = 0)
+    {
+        _searchSelectors = selectors ?? throw new ArgumentNullException(nameof(selectors));
         _searchTerm = term;
         _useWildcards = useWildcards;
 
@@ -190,7 +232,7 @@ public void SetSearch(Func<T, string> selector, string? term, bool useWildcards
     /// </summary>
     public void ClearSearch()
     {
-        _searchSelector = null;
+        _searchSelectors = [];
         _searchTerm = null;
         _useWildcards = false;
         ApplyFiltering();
@@ -230,19 +272,23 @@ private void ApplyFiltering()
             query = query.Where(filter);
         }
 
-        if (!string.IsNullOrWhiteSpace(_searchTerm) && _searchSelector != null)
+        if (!string.IsNullOrWhiteSpace(_searchTerm) && _searchSelectors.Any())
         {
+            var term = _searchTerm;
+            Func<string, bool> matches;
+
             if (_useWildcards)
             {
-                var regex = new Regex(WildcardToRegex(_searchTerm), RegexOptions.IgnoreCase);
-                query = query.Where(x => regex.IsMatch(_searchSelector(x)));
+                var regex = new Regex(WildcardToRegex(term), RegexOptions.IgnoreCase);
+                matches = s => regex.IsMatch(s);
             }
             else
             {
-                query = query.Where(x =>
-                    _searchSelector(x)
-                        ?.Contains(_searchTerm, StringComparison.OrdinalIgnoreCase) == true);
+                matches = s => s.Contains(term, StringComparison.OrdinalIgnoreCase);
             }
+
+            // OR logic for multi-column search
+            query = query.Where(item => _searchSelectors.Any(selector => matches(selector(item) ?? string.Empty)));
         }
 
         if (_sorts.Count > 0)