How to Auto update Geometry Properties using QGIS

It is possible to configure QGIS to automatically calculate and update properties like area, length, and perimeter as you digitize. Here’s how you can achieve this:
It is possible to configure QGIS to automatically calculate and update properties like area, length, and perimeter as you digitize. Here’s how you can achieve this:
1. Adding Fields for Area or Length in Attribute Table
 Open the Attribute Table for your layer.
 Click on the Toggle Editing Mode (pencil icon).
 Add new fields (e.g., Area, Length) to store these values:
 Click the New Field button.
 Set the field name (Area or Length) and data type (Decimal number or Real).
2. Using Default Values to Automatically Update
 Open Layer Properties:
 Right-click on the layer and select Properties.
 Go to Fields Section:
 In the left panel, choose Fields.
 Set Default Expressions:
 For the field you created (e.g., Area), click on the Default Value column.
 Enter an expression:
 For area: $area
 For length: $length
 These expressions will calculate the values based on the feature's geometry.
 Save your changes.
3. Test It
1. Start Digitizing:
 Enter Editing Mode and draw a new feature.
2. Check the Attribute Table:
 The Area or Length field should automatically populate as soon as you finish digitizing the feature.