I find myself faced with a problem:

I already have my shiny application (server part) like this :

observe({
      data <- my_function() %>%
       filter(col1 == "X1")

h <- sort(unique(data$year))

nb <- length(h)
lst <- as.list(h)

output$plot_name <- renderUI({
  plot_output <- lapply(1:nb,
                                 function(n1) {
                                   plotname <- paste0("plots", n1)
                                   plotOutput(plotname)
                                 })
  do.call(tagList, plot_output)
})

my_data <- list()

i <- 0
for (i in 1:length(lst)) {
  
  local({
    my_i <- i
    plotname <- paste0("plots", my_i)
    my_data[[my_i]] <- data %>% 
      filter(year == lst[[my_i]])
    
    output[[plotname]] <- renderPlot({
      
      g <- ggplot(..........)
      
      print(g)
      
    })
    
  })
}

})

that allows me to output, for each year, graphs for a given X.

However I would like to remove the filter and have for each year of each X a graph, knowing that I do not have the same number of years for all X (X1: 2000, X2: 2000 and 2001, X3 : 2001 etc.....).

Since I would like to determine dynamically the number of graphs.

If you have any clues, it will be very useful.

Thanks in advance.

CodePudding user response：

We can create all the plots inside a data frame and then count how many of them are they in order to create the corresponding outputs.

library(tidyverse)
library(shiny)


df <-
  read_table("col1 col2 year pts
X1 1 2000 24 
X1 2 2001 36 
X2 1 2000 48
X1 0 2000 24
X3 1 2000 72
X2 1 2000 24
X2 2 2002 48
X3 2 2001 24")



ui <- fluidPage(
  uiOutput("plot_name")
)

server <- function(input, output, session) {
  my_function <- reactive({
    df
  })
  
  observeEvent(my_function, {
    data <- my_function() 
    

# Create the plots --------------------------------------------------------

    
    plots_df <- 
      data %>% 
      group_by(col1, year) %>%
      summarise(plot = list(
        ggplot(cur_data_all() ,aes(x = pts, y = col2))  
          geom_point()  
          ggtitle(paste('col:', col1 ,'year:', year))
      ))
    

# plots UI ----------------------------------------------------------------

    
    nb <- length(plots_df$plot)
    plotname <- paste0("plots", 1:nb) # save the names for renderPlot functions

    output$plot_name <- renderUI({
      plot_output <- lapply(
        plotname,
        function(n1) {
          plotOutput(n1)
        }
      )
      do.call(tagList, plot_output)
    })


# renderPlot funcitons ----------------------------------------------------


    walk2(plotname, plots_df$plot, ~ {
      output[[.x]] <<- renderPlot({
        .y
      })
    })
   })
}

shinyApp(ui, server)