Focusedcellchanging Dxdatagrid

6 min read Oct 02, 2024

Focused Cell Changing in DevExtreme DataGrid: A Guide to Understanding and Controlling Cell Selection

The DevExtreme DataGrid offers a powerful and flexible way to display and interact with data. One of the key functionalities for user interaction is the ability to focus on and change cells within the grid. This article will delve into the concept of focused cell changing, exploring how it works, the events involved, and how you can customize its behavior to meet your specific application needs.

Understanding Focused Cell Changing

Focused cell changing refers to the process of moving the focus from one cell to another within the DevExtreme DataGrid. This can occur through various means, such as:

Keyboard Navigation: Using arrow keys or Tab key to navigate between cells.
Mouse Click: Selecting a cell by clicking on it with the mouse.
Programmatic Control: Setting the focusedRowKey and focusedColumnIndex properties of the DataGrid programmatically.

Key Events Involved

Several events are triggered during focused cell changing, allowing you to respond to and modify the behavior:

onCellPrepared: This event occurs when a cell is about to be rendered and displayed. You can use it to customize cell appearance based on the focused state.
onFocusedCellChanged: This event is fired when the focused cell changes. It provides information about the previous and current focused cell, enabling you to perform actions based on the change.
onEditorPreparing: This event is triggered when an editor is being prepared for a focused cell. It offers the opportunity to modify editor options or handle custom editing logic.
onEditingStart: This event is fired when editing starts in a cell. It can be used to validate input or set initial values for the editor.

Customizing Focused Cell Changing

The DevExtreme DataGrid provides several options to customize how focused cell changing works:

allowFocusedRowUpdating: This property enables or disables updating data in the focused row.
focusedRowKey: This property allows you to programmatically set the focused row.
focusedColumnIndex: This property allows you to programmatically set the focused column.
allowFocusedRowDblClickEdit: This property enables or disables editing a row by double-clicking on a cell.

Example: Customizing Cell Focus Appearance

import { DataGrid } from 'devextreme-react/data-grid';

const App = () => {
  return (
     {
        if (e.row.isFocused) {
          e.cellElement.style.backgroundColor = 'lightblue'; // Highlight focused cells
        }
      }}
    />
  );
};

export default App;

This example uses the onCellPrepared event to change the background color of a focused cell to light blue. You can customize this further to apply different styles or effects based on the focused cell's properties.

Example: Preventing Focus on Specific Cells

import { DataGrid } from 'devextreme-react/data-grid';

const App = () => {
  const onCellPrepared = (e) => {
    if (e.column.dataField === 'sensitiveData') {
      e.cellElement.classList.add('disabled-cell'); // Add a class to disable focus
    }
  };

  return (
    
  );
};

export default App;

In this example, we use the onCellPrepared event to add a class to cells containing sensitive data, preventing them from receiving focus. You can style this class in your CSS to visually indicate that the cell cannot be focused.

Conclusion

Focused cell changing is an essential aspect of user interaction with the DevExtreme DataGrid. By understanding the events and properties involved, you can effectively control the behavior of cell selection, customize its appearance, and implement custom logic to suit your application's needs. This allows you to create a more intuitive and engaging user experience for navigating and editing data within the grid.