Aggregates in Blazor DataGrid Component
23 Aug 202324 minutes to read
Aggregate values are displayed in the footer, group footer, or group caption of the Grid. It can be configured through GridAggregates component. Field and
Type are the minimum properties required to represent an aggregate column.
Built-in aggregate types
The aggregate type should be specified in the Type property to configure an aggregate column.
The built-in aggregates are,
- Sum
- Average
- Min
- Max
- Count
- TrueCount
- FalseCount
NOTE
- Multiple types for a column are supported only when one of the aggregate templates is used.
Footer aggregate
Footer aggregate value is calculated for all the rows, and it is displayed in the footer cells. Use the FooterTemplate tag directive to render the aggregate value in footer cells. FooterTemplate should be provided within the GridAggregateColumn directive.
To access the aggregate values inside the FooterTemplate, you can use the implicit named parameter context. You can type cast the context as AggregateTemplateContext to get aggregate values inside template.
@using Syncfusion.Blazor.Grids
<SfGrid DataSource="@Orders" AllowPaging="true">
<GridPageSettings PageSize="8"></GridPageSettings>
<GridAggregates>
<GridAggregate>
<GridAggregateColumns>
<GridAggregateColumn Field=@nameof(Order.Freight) Type="AggregateType.Sum" Format="C2">
<FooterTemplate>
@{
var aggregate = (context as AggregateTemplateContext);
<div>
<p>Sum: @aggregate.Sum</p>
</div>
}
</FooterTemplate>
</GridAggregateColumn>
</GridAggregateColumns>
</GridAggregate>
<GridAggregate>
<GridAggregateColumns>
<GridAggregateColumn Field=@nameof(Order.Freight) Type="AggregateType.Average" Format="C2">
<FooterTemplate>
@{
var aggregate = (context as AggregateTemplateContext);
<div>
<p>Average: @aggregate.Average</p>
</div>
}
</FooterTemplate>
</GridAggregateColumn>
</GridAggregateColumns>
</GridAggregate>
</GridAggregates>
<GridColumns>
<GridColumn Field=@nameof(Order.OrderID) HeaderText="Order ID" TextAlign="TextAlign.Right" Width="120"></GridColumn>
<GridColumn Field=@nameof(Order.CustomerID) HeaderText="Customer Name" Width="150"></GridColumn>
<GridColumn Field=@nameof(Order.OrderDate) HeaderText=" Order Date" Format="d" Type="ColumnType.Date" TextAlign="TextAlign.Right" Width="130"></GridColumn>
<GridColumn Field=@nameof(Order.Freight) HeaderText="Freight" Format="C2" TextAlign="TextAlign.Right" Width="120"></GridColumn>
</GridColumns>
</SfGrid>
@code{
public List<Order> Orders { get; set; }
protected override void OnInitialized()
{
Orders = Enumerable.Range(1, 75).Select(x => new Order()
{
OrderID = 1000 + x,
CustomerID = (new string[] { "ALFKI", "ANANTR", "ANTON", "BLONP", "BOLID" })[new Random().Next(5)],
Freight = 2.1 * x,
OrderDate = DateTime.Now.AddDays(-x),
}).ToList();
}
public class Order
{
public int? OrderID { get; set; }
public string CustomerID { get; set; }
public DateTime? OrderDate { get; set; }
public double? Freight { get; set; }
}
}The following image represents the FooterTemplate with aggregates
NOTE
The aggregate values must be accessed inside the template using their corresponding Type name.
How to format aggregate value
You can format the aggregate value result by using the Format property.
To access the aggregate values inside the FooterTemplate, you can use the implicit named parameter context. You can type cast the *context as AggregateTemplateContext to get aggregate values inside template.
@using Syncfusion.Blazor.Grids
<SfGrid DataSource="@Orders" AllowPaging="true">
<GridPageSettings PageSize="8"></GridPageSettings>
<GridAggregates>
<GridAggregate>
<GridAggregateColumns>
<GridAggregateColumn Field=@nameof(Order.Freight) Type="AggregateType.Sum" Format="C2">
<FooterTemplate>
@{
var aggregate = (context as AggregateTemplateContext);
<div>
<p>Sum: @aggregate.Sum</p>
</div>
}
</FooterTemplate>
</GridAggregateColumn>
</GridAggregateColumns>
</GridAggregate>
<GridAggregate>
<GridAggregateColumns>
<GridAggregateColumn Field=@nameof(Order.Freight) Type="AggregateType.Average" Format="C2">
<FooterTemplate>
@{
var aggregate = (context as AggregateTemplateContext);
<div>
<p>Average: @aggregate.Average</p>
</div>
}
</FooterTemplate>
</GridAggregateColumn>
</GridAggregateColumns>
</GridAggregate>
</GridAggregates>
<GridColumns>
<GridColumn Field=@nameof(Order.OrderID) HeaderText="Order ID" TextAlign="TextAlign.Right" Width="120"></GridColumn>
<GridColumn Field=@nameof(Order.CustomerID) HeaderText="Customer Name" Width="150"></GridColumn>
<GridColumn Field=@nameof(Order.OrderDate) HeaderText=" Order Date" Format="d" Type="ColumnType.Date" TextAlign="TextAlign.Right" Width="130"></GridColumn>
<GridColumn Field=@nameof(Order.Freight) HeaderText="Freight" Format="C2" TextAlign="TextAlign.Right" Width="120"></GridColumn>
</GridColumns>
</SfGrid>
@code{
public List<Order> Orders { get; set; }
protected override void OnInitialized()
{
Orders = Enumerable.Range(1, 75).Select(x => new Order()
{
OrderID = 1000 + x,
CustomerID = (new string[] { "ALFKI", "ANANTR", "ANTON", "BLONP", "BOLID" })[new Random().Next(5)],
Freight = 2.1 * x,
OrderDate = DateTime.Now.AddDays(-x),
}).ToList();
}
public class Order
{
public int? OrderID { get; set; }
public string CustomerID { get; set; }
public DateTime? OrderDate { get; set; }
public double? Freight { get; set; }
}
}Group and caption aggregate
Group and caption aggregate values are calculated from the current group items. If GroupFooterTemplate is provided, the aggregate values will be displayed in the group footer cells and if GroupCaptionTemplate is provided, aggregate values will be displayed in the group caption cells.
Both GroupCaptionTemplate and GroupFooterTemplate should be provided within the GridAggregateColumn directive.
To access the aggregate values inside the GroupFooterTemplate and GroupCaptionTemplate, you can use the implicit named parameter context. You can type cast the context as AggregateTemplateContext to get aggregate values inside template.
@using Syncfusion.Blazor.Grids
<SfGrid DataSource="@Products" AllowGrouping="true" AllowPaging="true">
<GridGroupSettings Columns=@Units></GridGroupSettings>
<GridAggregates>
<GridAggregate>
<GridAggregateColumns>
<GridAggregateColumn Field=@nameof(Product.UnitsInStock) Type="AggregateType.Sum">
<GroupFooterTemplate>
@{
var aggregate = (context as AggregateTemplateContext);
<div>
<p>Total units: @aggregate.Sum</p>
</div>
}
</GroupFooterTemplate>
</GridAggregateColumn>
<GridAggregateColumn Field=@nameof(Product.Discontinued) Type="AggregateType.TrueCount">
<GroupFooterTemplate>
@{
var aggregate = (context as AggregateTemplateContext);
<div>
<p>Truecount: @aggregate.TrueCount</p>
</div>
}
</GroupFooterTemplate>
</GridAggregateColumn>
<GridAggregateColumn Field=@nameof(Product.UnitsInStock) Type="AggregateType.Max">
<GroupCaptionTemplate>
@{
var aggregate = (context as AggregateTemplateContext);
<div>
<p>Maximum: @aggregate.Max</p>
</div>
}
</GroupCaptionTemplate>
</GridAggregateColumn>
</GridAggregateColumns>
</GridAggregate>
</GridAggregates>
<GridColumns>
<GridColumn Field=@nameof(Product.ProductName) HeaderText="Product Name" TextAlign="TextAlign.Right" Width="120"></GridColumn>
<GridColumn Field=@nameof(Product.QuantityPerUnit) HeaderText="Quantity Per Unit" Width="150"></GridColumn>
<GridColumn Field=@nameof(Product.UnitsInStock) HeaderText="Units In Stock" TextAlign="TextAlign.Right" Width="130"></GridColumn>
<GridColumn Field=@nameof(Product.Discontinued) HeaderText="Discontinued" TextAlign="TextAlign.Right" DisplayAsCheckBox="true" Type="ColumnType.Boolean"></GridColumn>
</GridColumns>
</SfGrid>
@code{
public List<Product> Products { get; set; }
private string[] Units = (new string[] { "QuantityPerUnit" });
protected override void OnInitialized()
{
Products = Enumerable.Range(1, 10).Select(x => new Product
{
ProductName = (new string[] { "Chai", "Chang", "Aniseed Syrup", "Chef Anton's Cajun Seasoning", "Chef Anton's Gumbo Mix" })[new Random().Next(5)],
QuantityPerUnit = (new string[] { "10 boxes x 20 bags", "24 - 12 oz bottles", "12 - 550 ml bottles", "48 - 6 oz jars", "36 boxes" })[new Random().Next(5)],
UnitsInStock = x,
Discontinued = (new bool[] { true, false})[new Random().Next(2)]
}).ToList();
}
public class Product
{
public string ProductName { get; set; }
public string QuantityPerUnit { get; set; }
public int UnitsInStock { get; set; }
public bool Discontinued { get; set; }
}
}The following image represents the Group and Caption template with aggregates.
NOTE
The aggregate values must be accessed inside the template using their corresponding Type name.
Custom aggregate
To calculate the aggregate value with your own aggregate functions, use the custom aggregate option.
To use Custom aggregate, specify the AggregateType as Custom in GridAggregateColumn directive and provide custom aggregate function inside the FooterTemplate as follows,
@using Syncfusion.Blazor.Grids
<SfGrid @ref="Grid" DataSource="@Products" AllowPaging="true">
<GridAggregates>
<GridAggregate>
<GridAggregateColumns>
<GridAggregateColumn Field=@nameof(Product.TotalSales) Type="AggregateType.Custom">
<FooterTemplate>
@{
<div>
<p>Custom: @GetWeightedAggregate()</p>
</div>
}
</FooterTemplate>
</GridAggregateColumn>
</GridAggregateColumns>
</GridAggregate>
</GridAggregates>
<GridColumns>
<GridColumn Field=@nameof(Product.ProductName) HeaderText="Product Name" TextAlign="TextAlign.Right" Width="150"></GridColumn>
<GridColumn Field=@nameof(Product.QuantityPerUnit) HeaderText="Quantity Per Unit" Width="150"></GridColumn>
<GridColumn Field=@nameof(Product.TotalSales) HeaderText="TotalSales" TextAlign="TextAlign.Right" Width="130"></GridColumn>
<GridColumn Field=@nameof(Product.TotalCosts) HeaderText="TotalCosts" TextAlign="TextAlign.Right" Width="180"></GridColumn>
</GridColumns>
</SfGrid>
@code{
SfGrid<Product> Grid { get; set; }
public List<Product> Products { get; set; }
public string GetWeightedAggregate()
{
// Here, you can calculate custom aggregate operations and return the result.
return Queryable.Sum(Products.Select(x => (x.TotalSales + x.TotalCosts) / x.TotalSales).AsQueryable()).ToString();
}
protected override void OnInitialized()
{
Products = Enumerable.Range(1, 5).Select(x => new Product
{
ProductName = (new string[] { "Chai", "Chang", "Aniseed Syrup", "Chef Anton's Cajun Seasoning", "Chef Anton's Gumbo Mix" })[new Random().Next(5)],
QuantityPerUnit = (new string[] { "10 boxes x 20 bags", "24 - 12 oz bottles", "12 - 550 ml bottles", "48 - 6 oz jars", "36 boxes" })[new Random().Next(5)],
TotalSales = 100 * x,
TotalCosts = 200 * x,
Discontinued = (new bool[] { true, false })[new Random().Next(2)]
}).ToList();
}
public class Product
{
public string ProductName { get; set; }
public string QuantityPerUnit { get; set; }
public int TotalSales { get; set; }
public int TotalCosts { get; set; }
public bool Discontinued { get; set; }
}
}NOTE
You can refer to the Blazor DataGrid feature tour page for its groundbreaking feature representations. You can also explore Blazor DataGrid example to understand how to present and manipulate data.
Reactive aggregate
When using batch editing, the aggregate values will be refreshed on every cell save. The footer, group footer, and group caption aggregate values will be refreshed.
NOTE
Adding a new record to the grouped DataGrid will not refresh the group summary and group caption aggregate’s value.
@using Syncfusion.Blazor.Grids
<SfGrid DataSource="@Orders" AllowPaging="true" AllowGrouping=true Toolbar="@ToolbarItems">
<GridEditSettings AllowDeleting="true" AllowEditing="true" Mode="EditMode.Batch"></GridEditSettings>
<GridAggregates>
<GridAggregate>
<GridAggregateColumns>
<GridAggregateColumn Field=@nameof(Order.Freight) Type="AggregateType.Sum" Format="C2">
<GroupFooterTemplate>
@{
var aggregate = (context as AggregateTemplateContext);
<div>
<p>Sum: @aggregate.Sum</p>
</div>
}
</GroupFooterTemplate>
</GridAggregateColumn>
<GridAggregateColumn Field=@nameof(Order.Freight) Type="AggregateType.Sum" Format="C2">
<FooterTemplate>
@{
var aggregate = (context as AggregateTemplateContext);
<div>
<p>Sum: @aggregate.Sum</p>
</div>
}
</FooterTemplate>
</GridAggregateColumn>
<GridAggregateColumn Field=@nameof(Order.Freight) Type="AggregateType.Average" Format="C2">
<GroupCaptionTemplate>
@{
var aggregate = (context as AggregateTemplateContext);
<div>
<p>Average: @aggregate.Average</p>
</div>
}
</GroupCaptionTemplate>
</GridAggregateColumn>
</GridAggregateColumns>
</GridAggregate>
</GridAggregates>
<GridColumns>
<GridColumn Field=@nameof(Order.OrderID) HeaderText="Order ID" IsPrimaryKey=true TextAlign="TextAlign.Right" Width="120"></GridColumn>
<GridColumn Field=@nameof(Order.CustomerID) HeaderText="Customer Name" Width="150"></GridColumn>
<GridColumn Field=@nameof(Order.Freight) HeaderText="Freight" Format="C2" TextAlign="TextAlign.Right" Width="120"></GridColumn>
<GridColumn Field=@nameof(Order.OrderDate) HeaderText=" Order Date" Format="d" Type="ColumnType.Date" TextAlign="TextAlign.Right" Width="130"></GridColumn>
<GridColumn Field=@nameof(Order.ShipCountry) HeaderText="Ship Country" Width="140"></GridColumn>
</GridColumns>
</SfGrid>
@code
{
private List<string> ToolbarItems = new List<string>(){ "Update","Cancel", "Delete"};
public List<Order> Orders { get; set; }
protected override void OnInitialized()
{
Orders = Enumerable.Range(1, 8).Select(x => new Order()
{
OrderID = 1000 + x,
CustomerID = (new string[] { "ALFKI", "ANANTR", "ANTON", "BLONP", "BOLID", "AROUT", "BERGS", "BLAUS" })[new Random().Next(8)],
Freight = 2.1 * x,
OrderDate = DateTime.Now.AddDays(-x),
ShipCountry = (new string[] { "Sweden", "Germany", "Argentina", "Mexico", "Denmark", "Finland", "Switzerland", "UK" })[new Random().Next(8)],
}).ToList();
}
public class Order
{
public int? OrderID { get; set; }
public string CustomerID { get; set; }
public DateTime? OrderDate { get; set; }
public string ShipCountry { get; set; }
public double? Freight { get; set; }
}
}