downloadHandler temp files should have same extension as final download file

Author: jcheng5

NEWS

@@ -11,6 +11,11 @@ shiny 0.11.0.9xxx
 * Switched from RJSONIO to jsonlite. This improves consistency and speed when
   converting between R data structures and JSON.
 
+* downloadHandler content callback functions are now invoked with a temp file
+  name that has the same extension as the final filename that will be used by
+  the download. This is to deal with the fact that some file writing functions
+  in R will auto-append the extension for their file type (pdf, zip).
+
 shiny 0.11
 --------------------------------------------------------------------------------
 

R/shiny.R

@@ -697,7 +697,15 @@ ShinySession <- R6Class(
             'Cache-Control' = 'no-cache')))
         }
 
-        tmpdata <- tempfile()
+        # Make temp file with the same extension as the user-visible filename.
+        # If the extension is not used, some functions such as pdf() and zip()
+        # may append the extension they expect, meaning the data we want will
+        # be written to a file other than our temp file (e.g. file1231.zip
+        # instead of file1231.zip).
+        ext <- tools::file_ext(filename)
+        if (nzchar(ext))
+          ext <- paste(".", ext, sep = "")
+        tmpdata <- tempfile(fileext = ext)
         result <- try(Context$new(getDefaultReactiveDomain(), '[download]')$run(
           function() { download$func(tmpdata) }
         ))

man/parseQueryString.Rd

@@ -17,7 +17,7 @@ list(i1 = list(j1 = 'x')), b = list(i1 = list(j1 = 'y'), i2 = list(j1 =
 `b[i1][j1]` = 'y', `b[i2][j1]` = 'z')} when \code{nested = FALSE}.}
 }
 \description{
-Returns a named character vector of key-value pairs.
+Returns a named list of key-value pairs.
 }
 \examples{
 parseQueryString("?foo=1&bar=b\%20a\%20r")