R: Make a reactive variable

makeReactiveBinding {shiny} | R Documentation

## Make a reactive variable

### Description

Turns a normal variable into a reactive variable, that is, one that has reactive semantics when assigned or read in the usual ways. The variable may already exist; if so, its value will be used as the initial value of the reactive variable (or `NULL` if the variable did not exist).

### Usage

    makeReactiveBinding(symbol, env = parent.frame())

### Arguments

`symbol` | A character string indicating the name of the variable that should be made reactive
`env` | The environment that will contain the reactive variable

### Value

None.

### Examples

    ## Not run:
    a <- 10
    makeReactiveBinding("a")
    b <- reactive(a * -1)
    observe(print(b()))
    a <- 20

    ## End(Not run)

[Package shiny version 1.2.0 Index]