It is often useful to summarize data that is displayed in a grid. For example, you may wish to display the number of rows, sum the values in a column, or calculate the average (mean) for a column.
Ext JS 4 provides a useful feature for grids to allow us to display a summary row in the last row or, if it is a grouped grid, in the last row of each group. The
Ext.grid.feature.GroupingSummary classes provide the tools required to do so:
This recipe will demonstrate how to add a summary row to your grid and perform custom rendering on the value.
We are going to ...