Shiny *for* loop to automatically download plots - r

Question

i'm quite new to shiny, and am trying to make a shiny app which allows the user to download all possible combination of a certain data with a simple download button.
However, it seems that shiny isn't allowing a standard for loop that i've been using outside of shiny
so basically what I'm trying to do with this reproducible data is to allow users to download all 9 possible scatter plots (1,1),(1,2),(1,3) etc
I've tried using lapply, isolate, local and so on, but it simple would either make 3 of the same plots, or not work like the current code
Help would be very, very, very appreciated.
Thank you in advance
this is my current UI
#UI
library(shiny)
library(datasets)
library(ggplot2)
Test1<- c(3,5,7)
Test2<- c(21000, 23400, 26800)
Test3<- c(600, 700, 800)
df <- data.frame(Test1, Test2, Test3)
rownames(df)<-colnames(df)
*ui <- shinyUI(fluidPage(
titlePanel("Column Plot"),
tabsetPanel(
tabPanel("First Type",
pageWithSidebar(
headerPanel('My First Plot'),
sidebarPanel(
selectInput('xcol', 'X Variable', ""),
selectInput('ycol', 'Y Variable', "", selected = ""),
actionButton(inputId = "clicks_3",label = "Real"),
),
mainPanel(
plotOutput('MyPlot')
)
)
)
)
)
)
this is my server
server <- shinyServer(function(input, output, session) {
data <- reactive({
updateSelectInput(session, inputId = 'xcol', label = 'X Variable',
choices = names(df), selected = names(df))
updateSelectInput(session, inputId = 'ycol', label = 'Y Variable',
choices = names(df), selected = names(df)[2])
return(df)
})
output$contents <- renderTable({
data()
})
output$MyPlot <- renderPlot({
x <- data()[, c(input$xcol, input$ycol)]
plot(x)
})
observeEvent(input$clicks_3,{
for (i in 1:3){
assign(paste("Plotinput_",i,sep = ""),({
x <- data()[, c(colnames(data())[i], input$ycol)]
plot(x)
}))
lapply(1:3, function(k){local({
ggsave(plot = eval(parse(text=paste("Plotinput_",k,sep = ""))),filename = paste(k,"barplot.png",collapse = ""))
})
})
}
})
})

Answer 1

If you want to download all plots, I would recommend a markdown report solution. In there, you can use lapply and iterate over all your plots. See https://shiny.rstudio.com/articles/generating-reports.html
In your code, it seems the brackets are not correct, see part below for a solution
observeEvent(input$clicks_3,{
for (i in 1:3){
assign(paste("Plotinput_",i,sep = ""),({
x <- data()[, c(colnames(data())[i], input$ycol)]
plot(x)
}))
}
lapply(1:3, function(k){local({
ggsave(plot = eval(parse(text=paste("Plotinput_",k,sep = ""))),filename = paste(k,"barplot.png",collapse = ""))
})
})
})