# exprToFunction

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##### Convert an expression to a function

This is to be called from another function, because it will attempt to get an unquoted expression from two calls back.

##### Usage
exprToFunction(expr, env = parent.frame(2), quoted = FALSE,
caller_offset = 1)
##### Arguments
expr
A quoted or unquoted expression, or a function.
env
The desired environment for the function. Defaults to the calling environment two steps back.
quoted
Is the expression quoted?
caller_offset
If specified, the offset in the callstack of the functiont to be treated as the caller.
##### Details

If expr is a quoted expression, then this just converts it to a function. If expr is a function, then this simply returns expr (and prints a deprecation message). If expr was a non-quoted expression from two calls back, then this will quote the original expression and convert it to a function.

##### Aliases
• exprToFunction
##### Examples
# Example of a new renderer, similar to renderText
# This is something that toolkit authors will do
renderTriple <- function(expr, env=parent.frame(), quoted=FALSE) {
# Convert expr to a function
func <- shiny::exprToFunction(expr, env, quoted)

function() {
value <- func()
paste(rep(value, 3), collapse=", ")
}
}

# Example of using the renderer.
# This is something that app authors will do.
values <- reactiveValues(A="text")

# Create an output object
output$tripleA <- renderTriple({ values$A
})

# At the R console, you can experiment with the renderer using isolate()
tripleA <- renderTriple({
values\$A
})

isolate(tripleA())
# "text, text, text"
Documentation reproduced from package shiny, version 0.9.0, License: GPL-3

### Community examples

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