This is what I'm suggesting:
library(shiny)
library(plotly)
ui <- fluidPage(
plotlyOutput("p"),
verbatimTextOutput("event")
)
x <- seq(-10, 10)
y <- rnorm(length(x))
server <- function(input, output, session) {
output$p <- renderPlotly({
d <- event_data("plotly_relayout", source = "trajectory")
selected_point <- if (!is.null(d[["shapes[0].x0"]])) {
xint <- d[["shapes[0].x0"]]
xpt <- x[which.min(abs(x - xint))]
list(x = xpt, y = y[which(x == xpt)])
} else {
list(x = 1, y = y[which(x == 1)])
}
plot_ly(color = I("red"), source = "trajectory") %>%
add_lines(x = x, y = y) %>%
add_markers(x = selected_point$x, y = selected_point$y) %>%
layout(
shapes = list(
type = "line",
line = list(color = "gray", dash = "dot"),
x0 = selected_point$x,
x1 = selected_point$x,
y0 = 0,
y1 = 1,
yref = "paper"
)
) %>%
config(editable = TRUE)
})
}
shinyApp(ui, server)
