Blazor Tree Grid Sorting

The Ignite UI for Blazor Data Sorting feature in Blazor Tree Grid is enabled on a per-column level, meaning that the IgbTreeGrid can have a mix of sortable and non-sortable columns. Performing Blazor sort actions enables you to change the display order of the records based on specified criteria.

Blazor Tree Grid Sorting Overview Example

This is done via the Sortable input. With the IgbTreeGrid sorting, you can also set the SortingIgnoreCase property to perform case sensitive sorting:

<IgbColumn Field="Title" Sortable="true"></IgbColumn>

Sorting Indicators

Having a certain amount of sorted columns could be really confusing if there is no indication of the sorted order.

The IgbTreeGrid provides a solution for this problem by indicating the index of each sorted column.

Sorting through the API

You can sort any column or a combination of columns through the IgbTreeGrid API using the IgbTreeGrid Sort method:

@code {
    this.grtreeGridid.SortAsync(new IgbSortingExpression[]
        {
            new IgbSortingExpression
            {
                FieldName = "Category",
                Dir = SortingDirection.Asc
            },
            new IgbSortingExpression
            {
                FieldName = "Price",
                Dir = SortingDirection.Desc
            }
        });
}

[!Note] Sorting is performed using our DefaultSortingStrategy algorithm. Any IgbColumn or ISortingExpression can use a custom implementation of the ISortingStrategy as a substitute algorithm. This is useful when custom sorting needs to be defined for complex template columns, or image columns, for example.

As with the filtering behavior, you can clear the sorting state by using the ClearSort method:

@code {
    @*Removes the sorting state from the Category column*@
    this.treeGrid.ClearSortAsync("Category");

    @*Removes the sorting state from every column in the Grid*@
    this.treeGrid.ClearSortAsync("");
}

[!Note] The SortStrategy of the IgbTreeGrid is of different type compared to the SortStrategy of the IgbColumn, since they work in different scopes and expose different parameters.

[!Note] The sorting operation DOES NOT change the underlying data source of the IgbTreeGrid.

Initial Sorting State

It is possible to set the initial sorting state of the IgbTreeGrid by passing an array of sorting expressions to the SortingExpressions property of the IgbTreeGrid.

@code {
    protected override void OnAfterRender(bool first)
    {
        if (first)
        {
            this.treeGrid.SortingExpressions = new IgbSortingExpression[]{
                new IgbSortingExpression()
                {
                    FieldName = "Category",
                    Dir = SortingDirection.Asc
                }};
        }
    }
}

[!Note] If values of type string are used by a column of DataType Date, the IgbTreeGrid won't parse them to Date objects and using IgbTreeGrid Sorting won't work as expected. If you want to use string objects, additional logic should be implemented on an application level, in order to parse the values to Date objects.

Sorting Indicators Templates

The sorting indicator icon in the column header can be customized using a template. The following properties are available for templating the sorting indicator for any sorting state (ascending, descending, none):

SortHeaderIconTemplate – re-templates the sorting icon when no sorting is applied.

<IgbTreeGrid SortHeaderIconTemplate="SortDefaultTemplate"></IgbTreeGrid>

@code {
    public RenderFragment<IgbGridHeaderTemplateContext> SortDefaultTemplate = (ctx) =>
    {
        return @<IgbIcon Size="SizableComponentSize.Small" IconName="unfold_more" Collection="material"></IgbIcon>;
    };
}

SortAscendingHeaderIconTemplate – re-templates the sorting icon when the column is sorted in ascending order.

<IgbTreeGrid SortAscendingHeaderIconTemplate="SortAscendingTemplate"></IgbTreeGrid>

@code {
    public RenderFragment<IgbGridHeaderTemplateContext> SortAscendingTemplate = (ctx) =>
    {
        return @<IgbIcon Size="SizableComponentSize.Small" IconName="expand_less" Collection="material"></IgbIcon>;
    };
}

SortDescendingHeaderIconTemplate – re-templates the sorting icon when the column is sorted in descending order.

<IgbTreeGrid SortDescendingHeaderIconTemplate="SortDescendingTemplate"></IgbTreeGrid>

@code {
    public RenderFragment<IgbGridHeaderTemplateContext> SortDescendingTemplate = (ctx) =>
    {
        return @<IgbIcon Size="SizableComponentSize.Small" IconName="expand_more" Collection="material"></IgbIcon>;
    };
}

Styling

In addition to the predefined themes, the grid could be further customized by setting some of the available CSS properties. In case you would like to change some of the colors, you need to set a class for the grid first:

<IgbTreeGrid class="grid">
</IgbTreeGrid>

Then set the related CSS properties to this class:

.grid {
    --ig-grid-sorted-header-icon-color: #ffb06a;
    --ig-grid-sortable-header-icon-hover-color: black;
}

Blazor Tree Grid Sorting