linking a node in networkD3 to a website using clickAction = NULL - r

Question

Is there a way to use a node as a link to an external website using the function forceNetwork() in the networkD3 package in r? I was thinking maybe modifying the clickAction?
Example data:
library(networkD3)
data(MisLinks)
data(MisNodes)
# Create a random URL in the nodes dataset
MisNodes$URL <- paste0("http://www.RANDOMLINK_", sample(1:100, NROW(MisNodes)), ".com")
head(MisNodes)
MyClickScript <- 'alert(d.index)'
forceNetwork(Links = MisLinks, Nodes = MisNodes,
Source = "source", Target = "target",
Value = "value", NodeID = "name",
Group = "group", opacity = 0.8,
clickAction = MyClickScript)
Desired outcome: When a user clicks on a node, a new tab will open (e.g. window.open) pointing to the associated URL for the node - How can I get clickAction to point to MisNodes$URL[d.index]?

Answer 1

networkD3 design does not make this easy. Here is one way to answer. I'll try to comment inline to explain what we are doing in each step.
library(networkD3)
# example from ?forceNetwork
data(MisLinks)
data(MisNodes)
# Create graph
fn <- forceNetwork(
Links = MisLinks, Nodes = MisNodes, Source = "source",
Target = "target", Value = "value", NodeID = "name",
Group = "group", opacity = 0.4, zoom = TRUE
)
# let's look at our forceNetwork
# nodes are provided to JavaScript
# in a nodes data.frame
str(fn$x$nodes)
# make up some links to demonstrate
# how we can add them to our nodes df
fn$x$nodes$hyperlink <- paste0(
'http://en.wikipedia.org/wiki/Special:Search?search=',
MisNodes$name
)
# then with our hyperlinks in our data
# we can define a click action to open
# the hyperlink for each node in a new window
fn$x$options$clickAction = 'window.open(d.hyperlink)'
fn