CODEWITHSUNDEEP
rlistshinyplotly
Siddharth Pandit
Siddharth Pandit

Reputation: 27

Returning plotly object in a list in Shiny

I've a shiny app in which a custom function perform data manipulation and returns a combination of data frames and a plotly graph. However, let me create a example using mtcars which will illustrate the problem.

Custom function returning a list which has a plotly object and one other variable.

get_plot <- function(x_var)
{

  p <- plot_ly() %>%
  add_lines(data = mtcars, x = ~x_var, y = ~mpg, mode = "lines", line = list(width = 2), name = "Original") %>% layout(hovermode = 'compare') %>%
  layout(  xaxis = list(title = print('x_var'), gridcolor = "#bfbfbf", domain = c(0, 0.98)),
           yaxis = list(title = "MPG", gridcolor = "#bfbfbf"))
  p <- plotly_build(p)

  a <- 1+1
  return(list(p,a))
}

Shiny Code:

source("get_plot.R")

library(shiny)

ui <- fluidPage(

   titlePanel("Example"),

   sidebarLayout(
      sidebarPanel(
         selectInput("x_var",
                     "Select X Axis variable",
                     c("hp","dist","drat","wt","disp","qsec","mpg"))
      ),

      mainPanel(
         plotlyOutput("distPlot")
      )
   )
)

server <- function(input, output) {

   output$distPlot <- renderPlotly({

          get_plot(input$x_var)[1]
   })
}

# Run the application 
shinyApp(ui = ui, server = server)

If you run this app, you will get the following error:

Error: no applicable method for 'ggplotly' applied to an object of class "list"

I understand what this means but I would like to ask whether there is a way to return a plotly object as part of a list in any other way. In my original shiny app the custom function does a lot of data processing after which it returns those data frames and the plotly object in a list. I am not able to access it and for now am getting around by making a copy of the same function and having it return just the plotly object. Not the most efficient obviously.

Thanks!

Upvotes: 1

Views: 677

Answers (1)

Florian
Florian

Reputation: 25415

I think all you have to do is to use double brackets, since you are indexing a list:

  output$distPlot <- renderPlotly({
    get_plot(input$x_var)[[1]]
  })

Hope this helps!

Upvotes: 3

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