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shiny/man/markRenderFunction.Rd
2020-12-02 16:17:08 -06:00

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% 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{
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.
}
\seealso{
\code{\link[=createRenderFunction]{createRenderFunction()}}, \code{\link[=quoToFunction]{quoToFunction()}}
}