Execute custom JavaScript code after rendering
Use this function to supplement the widget's built-in JavaScript rendering logic with additional custom JavaScript code, just for this specific widget object.
onRender(x, jsCode, data = NULL)
x |
An HTML Widget object |
jsCode |
Character vector containing JavaScript code (see Details) |
data |
An additional argument to pass to the |
The 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 x
parameter in createWidget). The third argument is the JavaScript
equivalent of the R object passed into onRender as the 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 this keyword will refer to the
widget instance object.
The modified widget object
onStaticRenderComplete, for writing custom JavaScript
that involves multiple widgets.
## Not run:
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)
## End(Not run)Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.