Render vector as comma separated text in shiny app using htmlOutput - html

Question

I want to use htmlOutput to render text in shiny app.
App works if I have just one object selected in the select input !
As soon as input$var has more than one object the result is not as I expected
require(shiny)
runApp(list(ui = pageWithSidebar(
headerPanel("Test"),
sidebarPanel(
selectInput("var",
label = "Choose a variable to display",
choices = c("Text01", "Text02",
"Text03", "Text04"),multiple = TRUE,
selected = "Text01"),
sliderInput("range",
label = "Range of interest:",
min = 0, max = 100, value = c(0, 100))
),
mainPanel(htmlOutput("text"))
),
server = function(input, output) {
output$text <- renderUI({
str1 <- paste("You have selected", input$var)
str2 <- paste("You have chosen a range that goes from",
input$range[1], "to", input$range[2])
HTML(paste(str1, str2, sep = '<br/>'))
})
}
)
)
How do I modify the code to hav output like :
You have selected Text01,Text02
You have chosen a range that goes from 0 to 100.

Answer 1

I'd recommend using the base R function toString() instead of a second paste:
library(shiny)
runApp(list(
ui = pageWithSidebar(
headerPanel("Test"),
sidebarPanel(
selectInput(
"var",
label = "Choose a variable to display",
choices = c("Text01", "Text02",
"Text03", "Text04"),
multiple = TRUE,
selected = "Text01"
),
sliderInput(
"range",
label = "Range of interest:",
min = 0,
max = 100,
value = c(0, 100)
)
),
mainPanel(htmlOutput("text"))
),
server = function(input, output) {
output$text <- renderUI({
str1 <- paste("You have selected", toString(input$var))
str2 <- sprintf("You have chosen a range that goes from %s to %s", input$range[1], input$range[2])
HTML(paste(str1, str2, sep = '<br/>'))
})
}
))

Answer 2

Just replace the line
str1 <- paste("You have selected", input$var)
with
str1 <- paste("You have selected", paste(input$var, collapse = ", "))
The problem is that paste() returns a vector of strings when input$var has more than 1 element. With collapse you reduce a string vector input$var to a single value.

Answer 3

library(shiny)
runApp(list(ui = pageWithSidebar(
headerPanel("Test"),
sidebarPanel(
selectInput("var",
label = "Choose a variable to display",
choices = c("Text01", "Text02",
"Text03", "Text04"), multiple = TRUE,
selected = "Text01"),
sliderInput("range",
label = "Range of interest:",
min = 0, max = 100, value = c(0, 100))
),
mainPanel(htmlOutput("text"))
),
server = function(input, output) {
output$text <- renderUI({
str1 <- paste(input$var, collapse = " ")
str2 <- paste("You have chosen a range that goes from",
input$range[1], "to", input$range[2])
tagList(
div("You have selected", str1),
div(str2))
})
}
)
)