observe_class_swap: swap out classes on an html element

In ijlyttle/shinypod: Reusable shiny modules

Description

This function stores the value of the last class to be added (using this function), then removes that class before addding the new class. For example, this may be useful if you want to modify a panel to show an alert.

Usage

observe_class_swap(id, expr, env = parent.frame(), quoted = FALSE)

Arguments

id	A character vector to identify the html element to operate on.
expr	An expression that returns a character vector to add to the html element.
env	The environment in which to evaluate expr.
quoted	Is expr a quoted expression (with quote())? This is useful if you want to save an expression in a variable.

Details

As this is an observer, there is no return value. It is called for the side-effect of changing the class of the html element.

This is based on shiny::renderText()

Value

nothing

ijlyttle/shinypod documentation built on May 18, 2019, 3:41 a.m.