shiny reactive, reactiveValue and eventReactive, observe and observeEvent in Shiny
Introduction
reactive, reactiveValue and eventReactive are various kinds of reactive expressions in Shiny. They yield output which can be used as input in other expressions, which will in turn take a dependency on the reactive expression.
observe and observeEvent are similar to reactive expressions. The big difference is that the observers do not yield any output and thus they are only useful for their side effects.
Examples of their use are given in this document.
