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% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/htmlwidgets.R
\name{onRender}
\alias{onRender}
\title{Execute custom JavaScript code after rendering}
\usage{
onRender(x, jsCode, data = NULL)
}
\arguments{
\item{x}{An HTML Widget object}
\item{jsCode}{Character vector containing JavaScript code (see Details)}
\item{data}{An additional argument to pass to the \code{jsCode} function.
This can be any R object that can be serialized to JSON. If you have
multiple objects to pass to the function, use a named list.}
}
\value{
The modified widget object
}
\description{
Use this function to supplement the widget's built-in JavaScript rendering
logic with additional custom JavaScript code, just for this specific widget
object.
}
\details{
The \code{jsCode} parameter must contain valid JavaScript code which
when evaluated returns a function.
The function will be invoked with three arguments: the first is the widget's
main HTML element, and the second is the data to be rendered (the \code{x}
parameter in \code{createWidget}). The third argument is the JavaScript
equivalent of the R object passed into \code{onRender} as the \code{data}
argument; this is an easy way to transfer e.g. data frames without having
to manually do the JSON encoding.
When the function is invoked, the \code{this} keyword will refer to the
widget instance object.
}
\examples{
\dontrun{
library(leaflet)
# This example uses browser geolocation. RStudio users:
# this won't work in the Viewer pane; try popping it
# out into your system web browser.
leaflet() \%>\% addTiles() \%>\%
onRender("
function(el, x) {
// Navigate the map to the user's location
this.locate({setView: true});
}
")
# This example shows how you can make an R data frame available
# to your JavaScript code.
meh <- "😐";
yikes <- "😨";
df <- data.frame(
lng = quakes$long,
lat = quakes$lat,
html = ifelse(quakes$mag < 5.5, meh, yikes),
stringsAsFactors = FALSE
)
leaflet() \%>\% addTiles() \%>\%
fitBounds(min(df$lng), min(df$lat), max(df$lng), max(df$lat)) \%>\%
onRender("
function(el, x, data) {
for (var i = 0; i < data.lng.length; i++) {
var icon = L.divIcon({className: '', html: data.html[i]});
L.marker([data.lat[i], data.lng[i]], {icon: icon}).addTo(this);
}
}
", data = df)
}
}
\seealso{
\code{\link{onStaticRenderComplete}}, for writing custom JavaScript
that involves multiple widgets.
}
|
