markRenderFunction.Rd

% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/shinywrappers.R
\name{markRenderFunction}
\alias{markRenderFunction}
\title{Mark a function as a render function}
\usage{
markRenderFunction(
  uiFunc,
  renderFunc,
  outputArgs = list(),
  cacheHint = "auto",
  cacheWriteHook = NULL,
  cacheReadHook = NULL
)
}
\arguments{
\item{uiFunc}{A function that renders Shiny UI. Must take a single argument:
an output ID.}

\item{renderFunc}{A function that is suitable for assigning to a Shiny output
slot.}

\item{outputArgs}{A list of arguments to pass to the \code{uiFunc}. Render
functions should include \code{outputArgs = list()} in their own parameter list,
and pass through the value to \code{markRenderFunction}, to allow app authors to
customize outputs. (Currently, this is only supported for dynamically
generated UIs, such as those created by Shiny code snippets embedded in R
Markdown documents).}

\item{cacheHint}{One of \code{"auto"}, \code{FALSE}, or some other information to
identify this instance for caching using \code{\link[=bindCache]{bindCache()}}. If \code{"auto"}, it
will try to automatically infer caching information. If \code{FALSE}, do not
allow caching for the object. Some render functions (such as \link{renderPlot})
contain internal state that makes them unsuitable for caching.}

\item{cacheWriteHook}{Used if the render function is passed to \code{bindCache()}.
This is an optional callback function to invoke before saving the value
from the render function to the cache. This function must accept one
argument, the value returned from \code{renderFunc}, and should return the value
to store in the cache.}

\item{cacheReadHook}{Used if the render function is passed to \code{bindCache()}.
This is an optional callback function to invoke after reading a value from
the cache (if there is a cache hit). The function will be passed one
argument, the value retrieved from the cache. This can be useful when some
side effect needs to occur for a render function to behave correctly. For
example, some render functions call \code{\link[=createWebDependency]{createWebDependency()}} so that Shiny
is able to serve JS and CSS resources.}
}
\value{
The \code{renderFunc} function, with annotations.
}
\description{
\ifelse{html}{\href{https://lifecycle.r-lib.org/articles/stages.html#superseded}{\figure{lifecycle-superseded.svg}{options: alt='[Superseded]'}}}{\strong{[Superseded]}} Please use \code{\link[=createRenderFunction]{createRenderFunction()}} to
support async execution. (Shiny 1.1.0)
}
\details{
Should be called by implementers of \code{renderXXX} functions in order to mark
their return values as Shiny render functions, and to provide a hint to Shiny
regarding what UI function is most commonly used with this type of render
function. This can be used in R Markdown documents to create complete output
widgets out of just the render function.

Note that it is generally preferable to use \code{\link[=createRenderFunction]{createRenderFunction()}} instead
of \code{markRenderFunction()}. It essentially wraps up the user-provided
expression in the \code{transform} function passed to it, then passes the resulting
function to \code{markRenderFunction()}. It also provides a simpler calling
interface. There may be cases where \code{markRenderFunction()} must be used instead of
\code{\link[=createRenderFunction]{createRenderFunction()}} -- for example, when the \code{transform} parameter of
\code{\link[=createRenderFunction]{createRenderFunction()}} is not flexible enough for your needs.
}
\seealso{
\code{\link[=createRenderFunction]{createRenderFunction()}}
}