Unidirectional data flow (UDF) 状态向下流动、事件向上流动的这种模式称为单向数据流 (UDF)。

• How to define the UI state.
• Unidirectional data flow (UDF) as a means of producing and managing the UI state.
• How to expose UI state with observable data types according to UDF principles.
• How to implement UI that consumes the observable UI state.