R: Parse a GET query string from a URL

parseQueryString {shiny} | R Documentation

## Parse a GET query string from a URL

### Description

Returns a named list of key-value pairs.

### Usage

    parseQueryString(str, nested = FALSE)

### Arguments

`str` | The query string. It can have a leading `"?"` or not.
`nested` | Whether to parse the query string of as a nested list when it contains pairs of square brackets `[]`. For example, the query a[i1][j1]=x&b[i1][j1]=y&b[i2][j1]=z will be parsed as `list(a = list(i1 = list(j1 = 'x')), b = list(i1 = list(j1 = 'y'), i2 = list(j1 = 'z')))` when `nested = TRUE`, and `list(`a[i1][j1]` = 'x', `b[i1][j1]` = 'y', `b[i2][j1]` = 'z')` when `nested = FALSE`.

### Examples

    parseQueryString("?foo=1&bar=b%20a%20r")

    ## Not run:
    # Example of usage within a Shiny app
    function(input, output, session) {

      output$queryText <- renderText({
        query <- parseQueryString(session$clientData$url_search)

        # Ways of accessing the values
        if (as.numeric(query$foo) == 1) {
          # Do something
        }
        if (query[["bar"]] == "targetstring") {
          # Do something else
        }

        # Return a string with key-value pairs
        paste(names(query), query, sep = "=", collapse=", ")
      })
    }

    ## End(Not run)

[Package shiny version 1.2.0 Index]