groupItems[]

Specifies items of the group summary.

Type: Array
Default Value: undefined

The group summary provides a synopsis of a group of data. Groups of data are formed in the process of grouping. The group summary contains several items. Each item displays a value that is a product of applying an aggregate function to a group of data.

To specify the items of the group summary, declare an array of objects, each of which contains at least two fields: column and summaryType. The column field specifies the identifier of the column that provides data for an aggregate function. The summaryType specifies the aggregate function to be applied. The following code snippet shows how to declare two summary items.

JavaScript
$("#gridContainer").dxDataGrid({
    // ...
    summary: {
        groupItems: [{
            column: 'Age',
            summaryType: 'avg'
        }, {
            column: 'LastName',
            summaryType: 'count'
        }]
    }
});

A group summary item may be located either in the group row or the group footer. By default, the group row holds all summary items. To locate a summary item in the group footer, set the showInGroupFooter option of this item to true.

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alignByColumn

Indicates whether to display group summary items in parentheses after the group row header or to align them by the corresponding columns within the group row.

Type: Boolean
Default Value: false

When this option is set to false, group summary items are displayed in brackets of the group row header. Set this option to true to align them by the corresponding columns within the group row.

You can also display group summary items in a group footer by setting the showInGroupFooter option to true.

NOTE
If this option is set to true for the first column of the grid, this setting is ignored (the summary item will be displayed in parentheses after the group row header). It happens because in the described case, the group header and the summary value occupy the same cell.

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column

Specifies the column that provides data for a group summary item.

Type: String
Default Value: undefined

To provide data for a group summary item, assign the name, data field or caption of a column to this option. This item will be displayed in each group row when grouping is applied. If you require to place the group summary item in the group footer, set the showInGroupFooter option to true for this item.

customizeText

Customizes the text to be displayed in the summary item.

Type: function(itemInfo)
Function parameters:
itemInfo: Object

Data of the summary item.

Object structure:

Summary item value as it was calculated.

valueText: String

Summary item value with applied format.

Return Value: String

Text to be displayed in the summary item.

This option accepts a function that must return the text to be displayed in the summary item. When you implement this function, you can access the summary item value using the fields of object passed to the function as its argument.

displayFormat

Specifies a pattern for the summary item text.

Type: String
Default Value: undefined

When implementing the pattern, you can access the summary item value with applied format using position marker 0. If the summary item is placed in any other column rather than its parent one, you can also access the caption of the parent column using position marker 1. Place each of these position markers within curly brackets.

If your scenario requires more complex text customizations, utilize the customizeText option.

name

Specifies the identifier of a summary item.

Type: String
Default Value: undefined

Specify this option if you need to refer to a summary item in your code afterwards, e.g., inside the calculateCustomSummary function.

precision

Deprecated

Use the valueFormat | precision option instead.

Specifies a precision for the summary item value of a numeric format.

Type: Number
Default Value: undefined

showInColumn

Specifies the column that must hold the summary item when this item is displayed in the group footer or aligned by a column in the group row.

Type: String
Default Value: undefined

A group summary item can be forced to be displayed in the group row by the column that provides data for this item. Alternatively, you can place an item to the group footer where the item is also held by the column that provides data for it. If you need to place an item in another column, assign the name, data field or caption of this column to the showInColumn option.

showInGroupFooter

Specifies whether or not a summary item must be displayed in the group footer.

Type: Boolean
Default Value: false

By default, summary items are displayed as a part of a group row. If you need a summary item to be displayed in the group footer, assign true to the showInGroupFooter option of this item. This summary item will be located in the column that provides data for it. If you want another column to hold the summary item, specify the showInColumn option of this item.

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skipEmptyValues

Specifies whether or not to skip empty strings, null and undefined values when calculating a summary.

Type: Boolean

Specified in a summary configuration object, this option affects an individual summary item. If you need to apply a single setting to all summaries in a grid, specify the skipEmptyValues option in the summary object.

JavaScript
var dataGridOptions = {
    // ...
    summary: {
        // ...
        skipEmptyValues: false
    }
}
NOTE
This option does not have any effect when you use a remote data source.
NOTE
Summaries of the count type do not skip empty values regardless of the skipEmptyValues option. However, you can implement a custom summary, which skips empty values, as follows.
JavaScript
var dataGridOptions = {
    // ...
    summary: {
        groupItems: [{
            // ...
            name: 'customSummary1',
            summaryType: 'custom'
        }],
        calculateCustomSummary: function (options) {
            if (options.name == 'customSummary1') {
                if (options.summaryProcess == 'start') {
                    options.totalValue = 0;
                }
                if (options.summaryProcess == 'calculate') {
                    if (e.value) {
                        options.totalValue++;
                    }
                }
            }
        }
    }
}

summaryType

Specifies how to aggregate data for a summary item.

Type: String
Default Value: undefined
Accepted Values: 'sum' | 'min' | 'max' | 'avg' | 'count' | 'custom'

A summary item displays a value that is a product of applying an aggregate function to a group of data from a specific column. This aggregate function is defined by the summary type. The following list gives an overview of available summary types.

  • "sum"
    Sums up all values in a column within the group.
  • "min"
    Calculates the minimum value in a column within the group.
  • "max"
    Calculates the maximum value in a column within the group.
  • "avg"
    Calculates the average of all values in a column within the group.
  • "count"
    Calculates the number of rows within the group.
  • "custom"
    Allows you to specify a custom aggregate function using the calculateCustomSummary option.

When using the widget as an ASP.NET MVC Control, specify this option using the SummaryType enum. This enum accepts the following values: Sum, Min, Max, Avg, Count and Custom.

valueFormat

Specifies a format for the summary item value.

Type: Format
Default Value: undefined
NOTE
DevExtreme widgets provide a wide choice of predefined formats. If you are, however, going to use custom formats, link the Globalize library to your project. Learn how to do this from topics in the Installation section.
See Also
  • format - a comprehensive overview of the capabilities provided by this option.