Example code to make a Sankey chart with plotly.

links <- data.frame(
  source=c("group_A","group_A", "group_B", "group_C", "group_C", "group_E"), 
  target=c("group_C","group_D", "group_E", "group_F", "group_G", "group_H"), 
  value=c(2,3, 2, 3, 1, 3)
)

nodes <- data.frame(
  name=c(as.character(links$source), 
         as.character(links$target)) %>% unique()
)

links$IDsource <- match(links$source, nodes$name)-1 
links$IDtarget <- match(links$target, nodes$name)-1

plot_ly(
  type = "sankey",
  orientation = "h",
  textfont = list(size=11),
  node = list(
    label = nodes$name,
    pad = 15,
    thickness = 20),
  link = list(
    source = links$IDsource,
    target = links$IDtarget,
    value =  links$value))

Is it possible to add the ‘value’ on each link ? (See my photo 1 for example) :

I would also like to simplify the text on the hover. Indeed, I want to delete the “source” and “target” information and simply add this text :value : [links$value]
I have tried using hovertemplate but apparently it is no longer a valid attributes. Here’s the expected output :

Thank you in advance.