# One-Way Binding

Some Page elements have a two-way binding nature. These controls can both read/write to the tag they are bound to, for example when a TextBox receives a new value, it may send the value back to the source tag where the value came from. To prevent any accidental value updates, there are two options:

1. Set the element's IsReadOnly property, which makes its binding one-way, i.e. it can receive updates, but will not write any changes back to the tag.

2. Use a Label which is always read-only.

Two-way controls with the IsReadOnly option:

- TextBox
- SelectionBox
- NumericEntry
- DateTimeEntry

Two-way controls without the IsReadOnly option (i.e. the updated value issue can still occur with these controls).

- Slider
- RadioButton
- PasswordBox
- CheckBox