Get the query string / hash component from the URL
Two user friendly wrappers for getting the query string and the hash component from the app's URL.
getQueryString(session = getDefaultReactiveDomain()) getUrlHash(session = getDefaultReactiveDomain())
session |
A Shiny session object. |
These can be particularly useful if you want to display different content
depending on the values in the query string / hash (e.g. instead of basing
the conditional on an input or a calculated reactive, you can base it on the
query string). However, note that, if you're changing the query string / hash
programatically from within the server code, you must use
updateQueryString(_yourNewQueryString_, mode = "push"). The default
mode for updateQueryString is "replace", which doesn't
raise any events, so any observers or reactives that depend on it will
not get triggered. However, if you're changing the query string / hash
directly by typing directly in the browser and hitting enter, you don't have
to worry about this.
For getQueryString, a named list. For example, the query
string ?param1=value1¶m2=value2 becomes list(param1 = value1, param2 = value2). For getUrlHash, a character vector with
the hash (including the leading # symbol).
## Only run this example in interactive R sessions
if (interactive()) {
## App 1: getQueryString
## Printing the value of the query string
## (Use the back and forward buttons to see how the browser
## keeps a record of each state)
shinyApp(
ui = fluidPage(
textInput("txt", "Enter new query string"),
helpText("Format: ?param1=val1¶m2=val2"),
actionButton("go", "Update"),
hr(),
verbatimTextOutput("query")
),
server = function(input, output, session) {
observeEvent(input$go, {
updateQueryString(input$txt, mode = "push")
})
output$query <- renderText({
query <- getQueryString()
queryText <- paste(names(query), query,
sep = "=", collapse=", ")
paste("Your query string is:\n", queryText)
})
}
)
## App 2: getUrlHash
## Printing the value of the URL hash
## (Use the back and forward buttons to see how the browser
## keeps a record of each state)
shinyApp(
ui = fluidPage(
textInput("txt", "Enter new hash"),
helpText("Format: #hash"),
actionButton("go", "Update"),
hr(),
verbatimTextOutput("hash")
),
server = function(input, output, session) {
observeEvent(input$go, {
updateQueryString(input$txt, mode = "push")
})
output$hash <- renderText({
hash <- getUrlHash()
paste("Your hash is:\n", hash)
})
}
)
}Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.