DxToolbar.DataMappings Property

Specifies data mappings.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v23.2.dll

NuGet Package: DevExpress.Blazor

Declaration

[Parameter]
public RenderFragment DataMappings { get; set; }

Property Value

Type	Description
RenderFragment	A UI fragment to be rendered as Toolbar items.

Remarks

You can populate the Toolbar component with items from a data source.

Follow the steps below to bind Toolbar to data:

1. Use the Data property to specify a data source. You can use different collection types:

   • Flat data (a collection of items organized as a single-level structure)
   • Hierarchical data (a collection of nested items)

2. Add the DataMappings tag to the component’s markup.

3. Create the DxToolbarDataMapping instance and map item properties (BeginGroup, NavigateUrl, and so on) to data source fields. Mappings are used to assign data from the source collection to the component’s data model.

   • For flat data collections, use the Key and ParentKey properties to create a hierarchy of items. If the Toolbar’s structure is linear, you can omit these properties.

   • For hierarchical data collections, the Children property is required to build the data model.

   You can create multiple DxToolbarDataMapping instances to specify different mappings for different nesting levels. Use the Level property to specify the item level for which data mappings are applied.

Flat Data

The code below binds the Toolbar to the flat collection of data items and specifies mappings for the Text, Key, and ParentKey properties.

Razor

<div class="card p-2">
    <DxToolbar Data=@FormatItem.ToolbarItems>
        <DataMappings>
            <DxToolbarDataMapping Text="ValueName" Key="Id" ParentKey="ParentId" />
        </DataMappings>
    </DxToolbar>
</div>

FormatItem.cs

public class FormatItem { 
    public string? ValueName { get; set; } 
    public int Id { get; set; }
    public int ParentId { get; set; }

    public IEnumerable<FormatItem> ToolbarItems = new List<FormatItem>() {
        new FormatItem() { ValueName = "Font", Id = 1 },
        new FormatItem() { ValueName = "Size", Id = 2 },
        new FormatItem() { ValueName = "Align", Id = 3 },
        new FormatItem() { ValueName = "Times New Roman", Id = 4, ParentId = 1 },
        new FormatItem() { ValueName = "Tahoma", Id = 5, ParentId = 1 },
        new FormatItem() { ValueName = "Verdana", Id = 6, ParentId = 1 },
        new FormatItem() { ValueName = "8px", Id = 7, ParentId = 2 },
        new FormatItem() { ValueName = "10px", Id = 8, ParentId = 2 },
        new FormatItem() { ValueName = "12px", Id = 9, ParentId = 2 },
    };
}  

Hierarchical Data

The code below binds the Toolbar to the collection of FormatItem objects. Each object can have child objects. The code specifies the Children, Text, and Checked mappings to adjust the Toolbar’s data model to the specified data source.

Razor

<div class="card p-2">
    <DxToolbar Data=@FormatItem.ToolbarItems ItemClick=@OnItemClicked>
        <DataMappings>
            <DxToolbarDataMapping Name="ValueName" Text="ValueName" Children="Values" Checked="IsChecked" />
            <DxToolbarDataMapping Text="Value" Level="1" />
        </DataMappings>
    </DxToolbar>
</div>

@code {
    void OnItemClicked(ToolbarItemClickEventArgs args) {
        if (args.ItemName == "Align") {
            ((FormatItem)args.Info.Data).ChangeChecked();
        }
    }
}

FormatItem.cs

public class FormatItem {
    public string? ValueName { get; set; }
    public List<FormatSubItem> Values { get; } = new List<FormatSubItem>();
    public bool IsChecked { get; set; }
    public void ChangeChecked() {
        IsChecked = !IsChecked;
    }
    public static IEnumerable<FormatItem> ToolbarItems = new List<FormatItem>() {
        new FormatItem() { ValueName = "Font", Values = {
                new FormatSubItem { Value = "Times New Roman" },
                new FormatSubItem { Value = "Tahoma" },
                new FormatSubItem { Value = "Verdana" }
            }
        },
        new FormatItem() { ValueName = "Size", Values = {
                new FormatSubItem { Value = "8px" },
                new FormatSubItem { Value = "10px" },
                new FormatSubItem { Value = "12px" }
            }
        },
        new FormatItem() {
            ValueName = "Align",
            IsChecked = true
        }
    };
}

public class FormatSubItem { 
    public string? Value; 
}

Run Demo: Toolbar - Data Binding Watch Video: Data Binding in Navigation Components