Interactivity in Sankey chart in R using networkD3 - r

Question

I wish to implement onClick on this sankey diagram such that by clicking on a link, I should see the details of the link between the two nodes. It's like the plotly_click function
library(networkD3)
nodes = data.frame("name" =
c("r1", # Node 0
"r2", # Node 1
"r3", # Node 2
"r4", # Node 3
"r5", # Node 4
"r6", # Node 5
"r7", # Node 6
"Blood Test", # Node 7
"Check Out", # Node 8
"Discuss Results", # Node 9
"MRI Scan", # Node 10
"Registration", # Node 11
"Triage and Assessment", # Node 12
"X-ray"))# Node 13
links = as.data.frame(matrix(c(
0, 11, 500, # Each row represents a link. The first number
1, 12, 500, # represents the node being conntected from.
2, 7, 237, # the second number represents the node connected to.
3, 10, 236,
4, 13, 261,
5, 9, 495,
6, 8, 492),# The third number is the value of the node
byrow = TRUE, ncol = 3))
names(links) = c("source", "target", "value")
sankeyNetwork(Links = links, Nodes = nodes,
Source = "source", Target = "target",
Value = "value", NodeID = "name",
fontSize= 12, nodeWidth = 30)

Answer 1

You can add click events using htmlwidgets::onRender function. It's not clear what details you want to see, but this, for example, will show a link's value in an alert box when you click it...
library(htmlwidgets)
sn <- sankeyNetwork(Links = links, Nodes = nodes,
Source = "source", Target = "target",
Value = "value", NodeID = "name",
fontSize = 12, nodeWidth = 30)
clickJS <- 'd3.selectAll(".link").on("click", function(d){ alert(d.value); })'
htmlwidgets::onRender(sn, clickJS)

Answer 2

Here is an interesting solution based on the parset package:
devtools::install_github("timelyportfolio/parsetR")
library(parsetR)
links$source <- as.character(factor(links$source, labels=nodes[1:7,1]))
links$target <- as.character(factor(links$target, labels=nodes[8:14,1]))
parset(links, dimensions = c('source', 'target'),
value = htmlwidgets::JS("function(d) {return d.value}"),
tension = 0.5)