I have a simple shiny app. First, I generated 2 csv files in my working directory:
write.csv(data.frame(a = 1:4, b = 2:5), "x.csv", row.names = F)
write.csv(data.frame(a = 1:4, c = 11:14), "y.csv", row.names = F)
In my app, I want the user to:
My code below works, but currently the messages for the user look very ugly and each is sitting on a dull gray background. Two questions:
Is my method the only method to print messages for the user? Or maybe there is a more elegant one?
How could I modify the gray background, font size, color, etc?
Thank you so much!
library(shiny)
library(shinyjs)
# ui code:
ui <- fluidPage(
useShinyjs(),
br(),
# User should upload file x.csv here:
fileInput("file_x", label = h5("Upload file 'x.csv'!")),
br(),
# User should upload file y.csv here:
fileInput("file_y", label = h5("Upload file 'y.csv'!")),
br(),
# Users clicks the button:
actionButton("do_it", "Run!"),
br(),
hidden(p("First, please upload one of the 2 files above!",
id = "p_nofiles",
style = "font-weight:bold;color:red;")),
br(),
verbatimTextOutput("message_1"),
br(),
verbatimTextOutput("message_2"),
br(),
verbatimTextOutput("message_3")
)
# server code:
server <- function(input, output, session) {
observeEvent(input$do_it, {
# If there file_x input is NULL, show the message in p_nofile
if (is.null(input$file_x) | is.null(input$file_y)) {
shinyjs::show("p_nofiles")
} else {
# if both files are selected, hide the p_nofiles message
shinyjs::hide("p_nofiles")
# Check my button's value:
output$print_action <- renderPrint({input$do_it})
# Read in file x_csv:
infileX <- input$file_x
if (is.null(infileX)) {
return(NULL)
}
x <- read.csv(infileX$datapath)
# Read in file y_csv:
infileY <- input$file_y
if (is.null(infileY)) {
return(NULL)
}
y <- read.csv(infileY$datapath)
#-------------------------------------------------------------------------------------------
# MESSAGES I WANT THE USER TO SEE:
# MESSAGE 1 - always there: What names do x and y have in common?
mes1 <- paste0("x and y have these columns in common: ",
intersect(names(x), names(y)), "\n")
output$message_1 <- renderText({mes1})
# MESSAGE 2 - with 2 alternative texts: Do x and y have the same number of rows?
if (nrow(x) == nrow(y)) {
mes2 <- "x and y have the same number of rows!\n"
} else {
mes2 <- "x has a different number of rows than y\n"
}
output$message_2 <- renderText({mes2})
# MESSAGE 3 - to be printed only under one condition:
# Do x and y have a different number of columns? Print only it's different, otherwise - nothing
if (ncol(x) != ncol(y)) {
mes3 <- "x and y do NOT have the same number of columns!\n"
output$message_3 <- renderText({mes3})
} else {output$message_3 <- renderText({NULL})}
#-------------------------------------------------------------------------------------------
# Writing out the same file x - but under a different name:
filenameX <- paste0("x", input$do_it, ".csv")
write.csv(x, file = filenameX, row.names = FALSE)
# Writing out the same file y - but under a different name:
filenameY <- paste0("y", input$do_it, ".csv")
write.csv(y, file = filenameY, row.names = FALSE)
}
})
}
shinyApp(ui, server)
I edited your code, try this. What you need to pay attention is the part that has showModal(...) in server.
library(shiny)
library(shinyjs)
ui <- fluidPage(
useShinyjs(),
br(),
# User should upload file x.csv here:
fileInput("file_x", label = h5("Upload file 'x.csv'!")),
br(),
# User should upload file y.csv here:
fileInput("file_y", label = h5("Upload file 'y.csv'!")),
br(),
# Users clicks the button:
actionButton("do_it", "Run!"),
br(),
hidden(p("First, please upload one of the 2 files above!",
id = "p_nofiles",
style = "font-weight:bold;color:red;"))
# br(),
# verbatimTextOutput("message_1"),
# br(),
# verbatimTextOutput("message_2"),
# br(),
# verbatimTextOutput("message_3")
)
server <- function(input, output, session) {
observeEvent(input$do_it, {
# If there file_x input is NULL, show the message in p_nofile
if (is.null(input$file_x) | is.null(input$file_y)) {
shinyjs::show("p_nofiles")
} else {
# if both files are selected, hide the p_nofiles message
shinyjs::hide("p_nofiles")
# Check my button's value:
output$print_action <- renderPrint({input$do_it})
# Read in file x_csv:
infileX <- input$file_x
if (is.null(infileX)) {
return(NULL)
}
x <- read.csv(infileX$datapath)
# Read in file y_csv:
infileY <- input$file_y
if (is.null(infileY)) {
return(NULL)
}
y <- read.csv(infileY$datapath)
#-------------------------------------------------------------------------------------------
# MESSAGES I WANT THE USER TO SEE:
# MESSAGE 1 - always there: What names do x and y have in common?
mes1 <- paste0("x and y have these columns in common: ",
intersect(names(x), names(y)), "\n")
# output$message_1 <- renderText({mes1})
# MESSAGE 2 - with 2 alternative texts: Do x and y have the same number of rows?
if (nrow(x) == nrow(y)) {
mes2 <- "x and y have the same number of rows!\n"
} else {
mes2 <- "x has a different number of rows than y\n"
}
# output$message_2 <- renderText({mes2})
# MESSAGE 3 - to be printed only under one condition:
# Do x and y have a different number of columns? Print only it's different, otherwise - nothing
if (ncol(x) != ncol(y)) {
mes3 <- "x and y do NOT have the same number of columns!\n"
# output$message_3 <- renderText({mes3})
} else {mes3 <- renderText({NULL})}
showModal(modalDialog(
title = "Mensagens to User",
"More Text",
mes1,
HTML("<br />"),
mes2,
HTML("<br />"),
mes3,
easyClose = TRUE,
footer = "Footer"
))
#-------------------------------------------------------------------------------------------
# Writing out the same file x - but under a different name:
filenameX <- paste0("x", input$do_it, ".csv")
write.csv(x, file = filenameX, row.names = FALSE)
# Writing out the same file y - but under a different name:
filenameY <- paste0("y", input$do_it, ".csv")
write.csv(y, file = filenameY, row.names = FALSE)
}
})
}
shinyApp(ui, server)