Merge pull request #2970 from rstudio/joe/feature/ui-http-response-2

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: shiny
 Type: Package
 Title: Web Application Framework for R
-Version: 1.5.0.9000
+Version: 1.5.0.9001
 Authors@R: c(
     person("Winston", "Chang", role = c("aut", "cre"), email = "winston@rstudio.com"),
     person("Joe", "Cheng", role = "aut", email = "joe@rstudio.com"),

NAMESPACE

@@ -116,6 +116,7 @@ export(hoverOpts)
 export(hr)
 export(htmlOutput)
 export(htmlTemplate)
+export(httpResponse)
 export(icon)
 export(imageOutput)
 export(img)

NEWS.md

@@ -6,6 +6,10 @@ shiny 1.5.0.9000
 
 * Added appropriate labels to `icon()` element to provide screen-reader users with alternative descriptions for the `fontawesome` and `glyphicon`: `aria-label` is automatically applied based on the fontawesome name. For example, `icon("calendar")` will be announced as "calendar icon" to screen readers. "presentation" aria role has also been attached to `icon()` to remove redundant semantic info for screen readers.
 
+### Minor new features and improvements
+
+* When UI is specified as a function (e.g. `ui <- function(req) { ... }`), the response can now be an HTTP response as returned from the (newly exported) `httpResponse()` function. (#2970)
+
 ### Bug fixes
 
 * Fixed #2859: `renderPlot()` wasn't correctly setting `showtext::showtext_opts()`'s `dpi` setting with the correct resolution on high resolution displays; which means, if the font was rendered by showtext, font sizes would look smaller than they should on such displays. (#2941)

R/middleware.R

@@ -14,7 +14,26 @@
 # returns `NULL`, or an `httpResponse`.
 #
 ## ------------------------------------------------------------------------
-httpResponse <- function(status = 200,
+
+#' Create an HTTP response object
+#'
+#' @param status HTTP status code for the response.
+#' @param content_type The value for the `Content-Type` header.
+#' @param content The body of the response, given as a single-element character
+#'   vector (will be encoded as UTF-8) or a raw vector.
+#' @param headers A named list of additional headers to include. Do not include
+#'   `Content-Length` (as it is automatically calculated) or `Content-Type` (the
+#'   `content_type` argument is used instead).
+#'
+#' @examples
+#' httpResponse(status = 405L,
+#'   content_type = "text/plain",
+#'   content = "The requested method was not allowed"
+#' )
+#'
+#' @keywords internal
+#' @export
+httpResponse <- function(status = 200L,
                          content_type = "text/html; charset=UTF-8",
                          content = "",
                          headers = list()) {

R/shinyui.R

@@ -24,7 +24,7 @@ withMathJax <- function(...) {
   )
 }
 
-renderPage <- function(ui, connection, showcase=0, testMode=FALSE) {
+renderPage <- function(ui, showcase=0, testMode=FALSE) {
   # If the ui is a NOT complete document (created by htmlTemplate()), then do some
   # preprocessing and make sure it's a complete document.
   if (!inherits(ui, "html_document")) {
@@ -77,7 +77,7 @@ renderPage <- function(ui, connection, showcase=0, testMode=FALSE) {
   }
 
   html <- renderDocument(ui, shiny_deps, processDep = createWebDependency)
-  writeUTF8(html, con = connection)
+  enc2utf8(paste(collapse = "\n", html))
 }
 
 #' Create a Shiny UI handler
@@ -101,16 +101,18 @@ uiHttpHandler <- function(ui, uiPattern = "^/$") {
 
   force(ui)
 
+  allowed_methods <- "GET"
+  if (is.function(ui)) {
+    allowed_methods <- attr(ui, "http_methods_supported", exact = TRUE) %OR% allowed_methods
+  }
+
   function(req) {
-    if (!identical(req$REQUEST_METHOD, 'GET'))
+    if (!isTRUE(req$REQUEST_METHOD %in% allowed_methods))
       return(NULL)
 
     if (!isTRUE(grepl(uiPattern, req$PATH_INFO)))
       return(NULL)
 
-    textConn <- file(open = "w+")
-    on.exit(close(textConn))
-
     showcaseMode <- .globals$showcaseDefault
     if (.globals$showcaseOverride) {
       mode <- showcaseModeOfReq(req)
@@ -150,8 +152,11 @@ uiHttpHandler <- function(ui, uiPattern = "^/$") {
     if (is.null(uiValue))
       return(NULL)
 
-    renderPage(uiValue, textConn, showcaseMode, testMode)
-    html <- paste(readLines(textConn, encoding = 'UTF-8'), collapse='\n')
-    return(httpResponse(200, content=enc2utf8(html)))
+    if (inherits(uiValue, "httpResponse")) {
+      return(uiValue)
+    } else {
+      html <- renderPage(uiValue, showcaseMode, testMode)
+      return(httpResponse(200, content=html))
+    }
   }
 }

inst/www/shared/shiny.js

@@ -9,7 +9,7 @@ function _defineProperty(obj, key, value) { if (key in obj) { Object.definePrope
 (function () {
   var $ = jQuery;
   var exports = window.Shiny = window.Shiny || {};
-  exports.version = "1.5.0.9000"; // Version number inserted by Grunt
+  exports.version = "1.5.0.9001"; // Version number inserted by Grunt
 
   var origPushState = window.history.pushState;
 

man/httpResponse.Rd

@@ -0,0 +1,36 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/middleware.R
+\name{httpResponse}
+\alias{httpResponse}
+\title{Create an HTTP response object}
+\usage{
+httpResponse(
+  status = 200L,
+  content_type = "text/html; charset=UTF-8",
+  content = "",
+  headers = list()
+)
+}
+\arguments{
+\item{status}{HTTP status code for the response.}
+
+\item{content_type}{The value for the \code{Content-Type} header.}
+
+\item{content}{The body of the response, given as a single-element character
+vector (will be encoded as UTF-8) or a raw vector.}
+
+\item{headers}{A named list of additional headers to include. Do not include
+\code{Content-Length} (as it is automatically calculated) or \code{Content-Type} (the
+\code{content_type} argument is used instead).}
+}
+\description{
+Create an HTTP response object
+}
+\examples{
+httpResponse(status = 405L,
+  content_type = "text/plain",
+  content = "The requested method was not allowed"
+)
+
+}
+\keyword{internal}

tools/documentation/pkgdown.yml

@@ -195,6 +195,7 @@ reference:
       - onStop
       - diskCache
       - memoryCache
+      - httpResponse
       - key_missing
   - title: Plot interaction
     desc: Functions related to interactive plots