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In a Shiny app, I want to create a link dynamically using a URL loaded from a file. The link appears inside a conditionalPanel. In my first attempt, the ui portion looked like this:

     conditionalPanel(condition = "input.myEvent",
            fluidRow(column(12,tags$p(textOutput("description")))),
            fluidRow(column(6, tags$a(href='http://www.google.com/', "Google"))),
            fluidRow(column(6, tags$a(href="url", 'website'))),

while the server portion looked like this:

    observeEvent(input$myEvent, { 
          p <- input$myEvent

          description = c(data[data$Name == p, ]$Description)
          output$description <- renderText(description)

          url1 = c(data[data$Name == p, ]$Website)
          output$url <- renderText(url1)
      }
    )

With this code, the URL is treated as the string "url" so it doesn't work.

I found another answer Create URL hyperlink in R Shiny?

however that example uses a static URL. I can't figure out how to make it dynamic. Here I made the UI section look like

    uiOutput("url")

and the server section look like:

          url <- a("website", href='url1')
          output$url <- renderUI({
              paste(url)
          })

But again the url is just the string 'url1', and again the url renders as text, rather than an a clickable link. It seems close, but a) how do I set the value of href in this server code to be a variable? b) how do I make the output an actual html anchor tag rather than just text.

L. Blanc
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1 Answers1

2

Not sure if this completely answers your question, but you might be missing HTML(paste(url)) to make it into a link.

library(shiny)

hrefs <- list('StackOverflow'= 'https://stackoverflow.com', 
              'R-project'= 'https://www.r-project.org/')

shinyApp(
  ui = fluidPage(
    selectInput('href_ref','Link:', 
                choices=names(hrefs), selected=names(hrefs)[1]),
    uiOutput("url")
  ),
  server = function(input, output) {
    output$url <- renderUI({
      url <- a("website", href=hrefs[input$href_ref])
      HTML(paste(url))
    })
  }
)
KM_83
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  • The HTML() call solves part of the problem, and your example of href=hrefs[] etc. solves the other part. IDK why i assumed the value in href= had to be a string literal. – L. Blanc Oct 08 '20 at 20:38