Here is a working example of extracting the on-click event. I would like to ask you if there is a way to update the clicked point with either increase in size or highlight it etc.,?
library(shiny)
library(plotly)
ui <- fluidPage(
plotlyOutput("plot"),
verbatimTextOutput("click")
)
server <- function(input, output, session) {
nms <- row.names(mtcars)
output$plot <- renderPlotly({
p <- ggplot(mtcars, aes(x = mpg, y = wt, col = as.factor(cyl), key = nms)) +
geom_point()
ggplotly(p)
})
output$click <- renderPrint({
d <- event_data("plotly_click")
if (is.null(d)) "Click events appear here (double-click to clear)"
else cat("Selected point associated with Car: ", d$key)
})
}
shinyApp(ui, server)
I have searched SO and other appropriate sources for finding a solution to the below question, but could not find one.
Update:
- This solution works better for this toy plot. But, my original use case contains 50+ levels for the variable of interest and there are high chances that Magenta or any other color would already be present. Also, it takes a considerable amount of time to change the color.
- Is there any way to increase the size of the clicked point to differentiate it from 100s of nearby points?
A related question to change the shape of the clicked point has been asked here.
You could add Plotly
's events to your Shiny app with htmlwidget
's onrender
function.
ggplotly(p) %>% onRender(javascript)
An array of colors
is passed to the restyle
function. The selected point (pointNumber
) is colored magenta while the others get the color from the legend. You could do the same thing with the marker
size, marker symbol is a bit more tricky because Plotly
does not accept arrays here.
function(el, x){
el.on('plotly_click', function(data) {
colors = [];
var base_color = document.getElementsByClassName('legendpoints')[data.points[0].curveNumber].getElementsByTagName('path')[0].style['stroke']
for (var i = 0; i < data.points[0].data.x.length; i += 1) {
colors.push(base_color)
};
colors[data.points[0].pointNumber] = '#FF00FF';
Plotly.restyle(el,
{'marker':{color: colors}},
[data.points[0].curveNumber]
);
});
}
library(shiny)
library(plotly)
library(htmlwidgets)
ui <- fluidPage(
plotlyOutput("plot")
)
javascript <- "
function(el, x){
el.on('plotly_click', function(data) {
colors = [];
var base_color = document.getElementsByClassName('legendpoints')[data.points[0].curveNumber].getElementsByTagName('path')[0].style['stroke']
for (var i = 0; i < data.points[0].data.x.length; i += 1) {
colors.push(base_color)
};
colors[data.points[0].pointNumber] = '#FF00FF';
Plotly.restyle(el,
{'marker':{color: colors}},
[data.points[0].curveNumber]
);
//make sure all the other traces get back their original color
for (i = 0; i < document.getElementsByClassName('plotly')[0].data.length; i += 1) {
if (i != data.points[0].curveNumber) {
colors = [];
base_color = document.getElementsByClassName('legendpoints')[i].getElementsByTagName('path')[0].style['stroke'];
for (var p = 0; p < document.getElementsByClassName('plotly')[0].data[i].x.length; p += 1) {
colors.push(base_color);
}
Plotly.restyle(el,
{'marker':{color: colors}},
[i]);
}
};
});
}"
server <- function(input, output, session) {
nms <- row.names(mtcars)
output$plot <- renderPlotly({
p <- ggplot(mtcars, aes(x = mpg, y = wt, col = as.factor(cyl), key = nms)) +
geom_point()
ggplotly(p) %>% onRender(javascript)
})
}
shinyApp(ui, server)
Some explanations:
- Plotly's events, e.g.
plotly_click
pass some information (data
in this case) in the event function
data.points
contains the points for which the event was triggered
- in this case, we only have one point
data.points[0]
where pointNumber
is the index of the original array and curveNumber
is the trace number.
- Plotly stores all the input data in the
div
where the plot is drawn
- We can access it via
document.getElementsByClassName('plotly')[0].data
- The legend can be accessed via
document.getElementsByClassName('legendpoints')[i]
where i
is the index of the legend
- ggplotly or plot_ly return htmlwidgets
- Javascript or HTML code can be added with any of the htmlwidget functions, e.g.
onrender
in this case