Filter Control

• Feb 17, 2023
• 2 minutes to read

The FilterControlExtension allows end users to build complex filter criteria with an unlimited number of filter conditions, combined by logical operators, and apply them to extensions or data models.

Run Demo: Filter Control Extension - Features

Features

Custom Appearance

The following table provides API members you can use to customize the filter control’s appearance.

Element	Property
Combining operator	FilterControlStyles.GroupType
Add and Remove buttons	FilterControlStyles.ImageButton
Comparison operator	FilterControlStyles.Operation
Field name area	FilterControlStyles.PropertyName
Filter area	FilterControlStyles.Table
Filter criteria value	FilterControlStyles.Value

Filter Expression Validation

Use the ASPxClientFilterControl.IsFilterExpressionValid and FilterControlExtension.GetFilterExpressionInfo methods to get whether the filter criteria is valid. These methods check whether an end-user has entered the required criteria values and indicate whether or not it’s safe to apply the criteria. You can define validation settings for each column separately. See the Validation topic to learn more.

Client-Side APIs

The ASPxClientFilterControl object serves as the FilterControlExtension‘s client-side equivalent and provides client-side APIs.

Method	Description
Apply	Applies the filter criteria.
GetAppliedFilterExpression	Gets the filter criteria that is applied to the associated extension.
GetEditor(index, valueIndex)	Returns the editor used to edit the specified filter column’s operand values.
GetFilterExpression	Gets the filter criteria.
IsFilterExpressionValid	Specifies whether the filter criteria is valid.
Reset	Resets the current filter criteria and returns it to the associated extension’s filter expression.

Implementation

Use the FilterControl(MVCxFilterControlSettings) helper method to add the Filter Control (FilterControlExtension) extension to a view. The method’s parameter provides access to the filter control’s settings (MVCxFilterControlSettings).

Declaration

The following code adds the filter control to a view.

FilterControlPartial.cshtml

var excludeColumnList = new List<string>() {
    "CategoryID", "ProductID", "SupplierID", "Supplier.SupplierID", "Supplier.HomePage",
    "Category.CategoryID", "Category.CategoryName", "EAN13"
};

Html.DevExpress().FilterControl<Product>(settings => {
    settings.Name = "filterControl";
    settings.Width = Unit.Percentage(100);
    settings.CallbackRouteValues = new { Controller = "Editors", Action = "FilterControlPartial" };
    settings.ClientSideEvents.Applied = "filterControl_Applied";
    settings.ViewMode = FilterControlViewMode.VisualAndText;
    settings.AllowHierarchicalColumns = true;
    settings.MaxHierarchyDepth = 1;

    settings.Init = (sender, e) => {
        var filterControl = (MVCxFilterControl)sender;
        excludeColumnList.ForEach(c => filterControl.Columns.Remove(c));

        var categoryNameColumn = new MVCxFilterControlColumn("CategoryName");
        categoryNameColumn.EditorProperties().ComboBox(p => {
            p.DataSource = DevExpress.Web.Demos.Mvc.NorthwindDataProvider.GetCategories();
            p.TextField = "CategoryName";
            p.ValueField = "CategoryName";
            p.ValueType = typeof(string);
        });
        var categoryColumn = (FilterControlComplexTypeColumn)filterControl.Columns["Category"];
        categoryColumn.Columns.Insert(0, categoryNameColumn);
    };
    settings.PreRender = (sender, e) => {
        var filterControl = (MVCxFilterControl)sender;
        filterControl.FilterExpression = "[Category.CategoryName] = 'Beverages'";
    };
}).GetHtml();

Note

The Partial View should contain only the extension’s code.