Merge pull request rstudio#473 from rstudio/aron/knit_params_ask

knit_params_ask and render(params=ask)

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: rmarkdown
 Type: Package
 Title: Dynamic Documents for R
-Version: 0.7.1
+Version: 0.7.3
 Date: 2015-06-13
 Author: JJ Allaire, Jonathan McPherson, Yihui Xie, Hadley Wickham, Joe Cheng,
     Jeff Allen

NAMESPACE

@@ -11,6 +11,7 @@ export(html_vignette)
 export(includes)
 export(includes_to_pandoc_args)
 export(ioslides_presentation)
+export(knit_params_ask)
 export(knitr_options)
 export(knitr_options_html)
 export(knitr_options_pdf)

R/html_resources.R

@@ -286,6 +286,22 @@ discover_rmd_resources <- function(rmd_file, encoding,
       discover_render_resource(front_matter[[bibfile]])  
     }
   }
+
+  # check for parameter values that look like files.
+  if (!is.null(front_matter$params)) {
+    # This is the raw parameter information and has not had any YAML tag
+    # processing performed. See `knitr:::resolve_params`.
+    lapply(front_matter$params, function(param) {
+      if (is.list(param)) {
+        if (identical(param$input, "file")) {
+          if (!is.null(param$value)) {
+            # We treat param filenames as non-web resources.
+            discover_single_resource(param$value, TRUE, FALSE)
+          }
+        }
+      }
+    })
+  }
 
   # check for knitr child documents in R Markdown documents
   if (tolower(tools::file_ext(rmd_file)) == "rmd") {