Reactive resizing of plotly graph in R Shiny - r

Question

My problem here is, I think, an edge case for this type of problem. With that said, I've got some reproducible code here that might help a lot of people with similar issues they have, particularly the issue of changing a ggplot's plot height in RShiny (which is default set to 400px).
Here is a demo of a shiny app where the height of the ggplot is set equal to the width of the ggplot:
mydf = data.frame(x = 1:5, y = 1:5)
# User Interface
# =================
ui <- fluidPage(theme = shinytheme('united'),
fluidRow(
column(width = 12, align = 'center',
plotOutput('myplot', height = 'auto')
)
))
# ====
# Server Code
# ==============
server <- shinyServer(function(input, output, session) {
# 3. Create the chart
# ===-===-===-===-===-===
output$myplot <- renderPlot({
ggplot(mydf, aes(x = x, y = x)) + geom_point()
}, height = function() { session$clientData$output_myplot_width })
})
# ====
shinyApp(ui, server)
Play around with the width of the window launched by launching this shiny app. By setting height = 'auto' in the UI, and then setting height = function() { session$clientData$output_myplot_width } in the Server, the height is dynamically updated. Very good indeed.
I am working on something similar in plotly, however a significant constraint that I have is that I currently need to pass a parameter for height and width to my call of plotly(), due to the very specific way I am trying to display the markers on my plot. An example of what I am trying to do is as such:
mydf <- data.frame(x = 1:5, y = 1:5)
myplotlyfunction <- function(mydf, myplotheight) {
plot_ly(mydf, height = myplotheight, width = myplotheight * 1.2) %>%
add_trace(x = ~x, y = ~y, type = 'scatter', mode = 'markers')
}
# User Interface
# =================
ui <- fluidPage(theme = shinytheme('united'),
fluidRow(
column(width = 12, align = 'center',
plotlyOutput('myplotly')
)
))
# ====
# Server Code
# ==============
server <- shinyServer(function(input, output, session) {
# 3. Create the chart
# ===-===-===-===-===-===
output$myplotly <- renderPlotly({
this.height <- 600
myplotlyfunction(mydf, myplotheight = this.height)
})
})
# ====
shinyApp(ui, server)
The specific reason why I need to pass a height and width parameter to the plot_ly() call is deserving of a post of its own, and unfortunately I haven't thought of a work around yet. Here is a real example of my plot_ly output -
At a high level, the marker size parameter for plot_ly scatter plots sets the marker sizes based on pixels, and my plot needs very specifically sized markers, and these marker sizes are therefore a function of the plot size.
Here is my attempt to make my plot_ly plots dynamic in Shiny, despite having to initially pass a fixed parameter to the plot_ly height. The idea is motivated on the initial ggplot() dynamic height function:
mydf <- data.frame(x = 1:5, y = 1:5)
myplotlyfunction <- function(mydf, myplotheight) {
plot_ly(mydf, height = myplotheight, width = myplotheight * 1.2) %>%
add_trace(x = ~x, y = ~y, type = 'scatter', mode = 'markers')
}
# User Interface
# =================
ui <- fluidPage(theme = shinytheme('united'),
fluidRow(
column(width = 12, align = 'center',
plotlyOutput('myplotly', height = 'auto')
)
))
# ====
# Server Code
# ==============
server <- shinyServer(function(input, output, session) {
# 3. Create the chart
# ===-===-===-===-===-===
output$myplotly <- renderPlotly({
this.height <- function() { session$clientData$output_myplotly_width }
myplotlyfunction(mydf, myplotheight = this.height)
}, height = function() { session$clientData$output_myplotly_width })
})
# ====
shinyApp(ui, server)
This does not work, and in fact the app crashes right away.
Thank you a ton for anybody who made it to the end of this post. Any help is appreciated regarding how I can dynamically resize a plot_ly() plot in R Shiny, based on the height or width of the app window, given that the plot_ly function itself requires a height parameter. Thoughts on how to solve the underlying problem of needing a height parameter to plot_ly() in the first place are appreciated as well, but that's a separate issue (that I've posted about myself, here - Set marker size based on coordinate values, not pixels, in plotly R - and in other posts as well).
Once again, thanks a ton for any help!