A method, software tool and system for communicating data between components in a client computer system is provided. The client computer system has a user interface for displaying a page comprising content rendered by a plurality of components. A property broker is provided which maintains a registry of linked source and destination data fields of components of the client computer system. The property broker is notified when a user request is detected by a component registered with the property broker, and a set of components registered with the property broker is then notified of the start of a communication phase. The user request is processed by the actioned component and the value of each source data field updated during processing of the user request is communicated to each component having a linked destination data field. The property broker notifies the set of components when the communications phase has ended, and at least one component then renders content for display.