Using Proxy Interface in Plotly/Shiny to dynamically change data - r

Question

I want to update the data present in a plot (displayed in plotlyOutput in a Shiny app) using Proxy Interface. Here is a minimal App.R code :
library(shiny)
library(plotly)
ui <- fluidPage(
actionButton("update", "Test"),
plotlyOutput("graphe")
)
server <- function(input, output, session) {
output$graphe <- renderPlotly({
p <- plot_ly(type="scatter",mode="markers")
p <- layout(p,title="test")
p <- add_trace(p, x=0,y=0,name="ABC_test",mode="lines+markers")
})
observeEvent(input$update, {
proxy <- plotlyProxy("graphe", session) %>%
plotlyProxyInvoke("restyle", list(x=0,y=1),0)
})
}
shinyApp(ui, server)
When I run it, the plot is displayed with a dot at (0,0) (as wanted) but when I click of the button "Test", the dot does not move to (0,1). How can I achieve this ?
Thank you for any answer.

Answer 1

Strangely enough addTracesdoes not work with only one point but works with two points. To make it work you could add the same point twice. So you could try this:
ui <- fluidPage(
actionButton("update", "Test"),
plotlyOutput("graphe")
)
server <- function(input, output, session) {
output$graphe <- renderPlotly({
p <- plot_ly(type="scatter",mode="markers")
p <- layout(p,title="test")
p <- add_trace(p, x=0,y=0,name="ABC_test",mode="lines+markers")
})
observeEvent(input$update, {
plotlyProxy("graphe", session) %>%
plotlyProxyInvoke("deleteTraces", list(as.integer(1))) %>%
plotlyProxyInvoke("addTraces", list(x=c(0, 0),y=c(1, 1),
type = 'scatter',
mode = 'markers'))
})
}
shinyApp(ui, server)

Answer 2

The restyle API is a bit wonky...I forget the reasoning, but data arrays like x and y need double arrays. I'd do it this way:
library(shiny)
library(plotly)
ui <- fluidPage(
actionButton("update", "Test"),
plotlyOutput("graphe")
)
server <- function(input, output, session) {
output$graphe <- renderPlotly({
plot_ly() %>%
add_markers(x = 0, y = 0, name = "ABC_test") %>%
layout(title = "test")
})
observeEvent(input$update, {
plotlyProxy("graphe", session) %>%
plotlyProxyInvoke("restyle", "y", list(list(1)), 0)
})
}
shinyApp(ui, server)

Answer 3

library(shiny)
ui <- fluidPage(
actionButton("update", "Test"),
plotlyOutput("graphe")
)
server <- function(input, output, session) {
output$graphe <- renderPlotly({
plot_ly() %>%
layout(title="test") %>%
add_trace(x=runif(2), y=runif(2), name="ABC_test", type="scatter", mode="lines+markers")
})
observeEvent(input$update, {
plotlyProxy("graphe", session, FALSE) %>%
plotlyProxyInvoke("deleteTraces", list(as.integer(0))) %>%
plotlyProxyInvoke("addTraces", list(x=runif(2),
y=runif(2),
name="ABC_test",
type = 'scatter',
mode = 'lines+markers'))
})
}
shinyApp(ui, server)