Use new renderTemplate function for scaffold instead of sprintf

Author: alandipert

R/scaffold.R

@@ -51,6 +51,15 @@ slurp <- function(file) {
   ), collapse = "\n")
 }
 
+# Perform a series of pattern replacements on str.
+# Example: renderTemplate("foo ${x} bar ${y} baz ${x}", list(x = 1, y = 2))
+# Produces: "foo 1 bar 2 baz 1"
+renderTemplate <- function(str, substitutions) {
+  Reduce(function(str, name) {
+    gsub(paste0("\\$\\{", name, "\\}"), substitutions[[name]], str)
+  }, names(substitutions), str)
+}
+
 capName = function(name){
   paste0(toupper(substring(name, 1, 1)), substring(name, 2))
 }
@@ -59,7 +68,7 @@ addWidgetConstructor <- function(name, package, edit){
   tpl <- slurp('templates/widget_r.txt')
   if (!file.exists(file_ <- sprintf("R/%s.R", name))){
     cat(
-      sprintf(tpl, name, name, package, name, name, name, name, name, name, package, name, capName(name), name, name, name),
+      renderTemplate(tpl, list(name = name, package = package, capName = capName(name))),
       file = file_
     )
     message('Created boilerplate for widget constructor ', file_)
@@ -93,7 +102,7 @@ addWidgetYAML <- function(name, edit){
 }
 
 addPackageJSON <- function(npmPkg) {
-  tpl <- sprintf(slurp('templates/widget_package.json.txt'), npmPkg)
+  tpl <- renderTemplate(slurp('templates/widget_package.json.txt'), list(npmPkg = npmPkg))
   if (!file.exists('package.json')) {
     cat(tpl, file = 'package.json')
     message('Created package.json')
@@ -103,7 +112,7 @@ addPackageJSON <- function(npmPkg) {
 }
 
 addWebpackConfig <- function(name) {
-  tpl <- sprintf(slurp('templates/widget_webpack.config.js.txt'), name, name)
+  tpl <- renderTemplate(slurp('templates/widget_webpack.config.js.txt'), list(name = name))
   if (!file.exists('webpack.config.js')) {
     cat(tpl, file = 'webpack.config.js')
     message('Created webpack.config.js')
@@ -120,7 +129,7 @@ addWidgetJS <- function(name, edit){
     dir.create('srcjs')
   }
   if (!file.exists(file_ <- sprintf('srcjs/%s.js', name))){
-    cat(sprintf(tpl, name), file = file_)
+    cat(renderTemplate(tpl, list(name = name)), file = file_)
     message('Created boilerplate for widget javascript bindings at ',
             sprintf('srcjs/%s.js', name)
     )
@@ -131,7 +140,7 @@ addWidgetJS <- function(name, edit){
 }
 
 addExampleApp <- function(name) {
-  tpl <- sprintf(slurp('templates/widget_app.R.txt'), name, name, capName(name), name)
+  tpl <- renderTemplate(slurp('templates/widget_app.R.txt'), list(name = name, capName = capName(name)))
   if (!file.exists('app.R')) {
     cat(tpl, file = 'app.R')
     message('Created example app.R')

inst/templates/widget_app.R.txt

@@ -1,14 +1,14 @@
 library(shiny)
-library(%s)
+library(${name})
 
 ui <- fluidPage(
   titlePanel("reactR HTMLWidget Example"),
-  %sOutput('widgetOutput')
+  ${name}Output('widgetOutput')
 )
 
 server <- function(input, output, session) {
-  output$widgetOutput <- render%s(
-    %s("Hello world!")
+  output$widgetOutput <- render${capName}(
+    ${name}("Hello world!")
   )
 }
 

inst/templates/widget_js.txt

@@ -1,3 +1,3 @@
 import { reactWidget } from 'reactR';
 
-reactWidget('%s', 'output', {});
+reactWidget('${name}', 'output', {});

inst/templates/widget_package.json.txt

@@ -1,7 +1,7 @@
 {
   "private": true,
   "dependencies": {
-    %s
+    ${npmPkg}
   },
   "devDependencies": {
     "webpack": "^4.27.1",

inst/templates/widget_r.txt

@@ -5,53 +5,53 @@
 #' @import htmlwidgets
 #'
 #' @export
-%s <- function(message, width = NULL, height = NULL, elementId = NULL) {
+${name} <- function(message, width = NULL, height = NULL, elementId = NULL) {
 
   # describe a React component to send to the browser for rendering.
   component <- reactR::reactMarkup(htmltools::tag("div", list(message)))
 
   # create widget
   htmlwidgets::createWidget(
-    name = '%s',
+    name = '${name}',
     component,
     width = width,
     height = height,
-    package = '%s',
+    package = '${package}',
     elementId = elementId
   )
 }
 
-#' Shiny bindings for %s
+#' Shiny bindings for ${name}
 #'
-#' Output and render functions for using %s within Shiny
+#' Output and render functions for using ${name} within Shiny
 #' applications and interactive Rmd documents.
 #'
 #' @param outputId output variable to read from
 #' @param width,height Must be a valid CSS unit (like \code{'100\%%'},
 #'   \code{'400px'}, \code{'auto'}) or a number, which will be coerced to a
 #'   string and have \code{'px'} appended.
-#' @param expr An expression that generates a %s
+#' @param expr An expression that generates a ${name}
 #' @param env The environment in which to evaluate \code{expr}.
 #' @param quoted Is \code{expr} a quoted expression (with \code{quote()})? This
 #'   is useful if you want to save an expression in a variable.
 #'
-#' @name %s-shiny
+#' @name ${name}-shiny
 #'
 #' @export
-%sOutput <- function(outputId, width = '100%%', height = '400px'){
-  htmlwidgets::shinyWidgetOutput(outputId, '%s', width, height, package = '%s')
+${name}Output <- function(outputId, width = '100%%', height = '400px'){
+  htmlwidgets::shinyWidgetOutput(outputId, '${name}', width, height, package = '${package}')
 }
 
-#' @rdname %s-shiny
+#' @rdname ${name}-shiny
 #' @export
-render%s <- function(expr, env = parent.frame(), quoted = FALSE) {
+render${capName} <- function(expr, env = parent.frame(), quoted = FALSE) {
   if (!quoted) { expr <- substitute(expr) } # force quoted
-  htmlwidgets::shinyRenderWidget(expr, %sOutput, env, quoted = TRUE)
+  htmlwidgets::shinyRenderWidget(expr, ${name}Output, env, quoted = TRUE)
 }
 
 #' Called by HTMLWidgets to produce the widget's root element.
-#' @rdname %s-shiny
-%s_html <- function(id, style, class, ...) {
+#' @rdname ${name}-shiny
+${name}_html <- function(id, style, class, ...) {
   tagList(
     reactR::html_dependency_react(),
     reactR::html_dependency_reacttools(),

inst/templates/widget_webpack.config.js.txt

@@ -1,10 +1,10 @@
 var path = require('path');
 
 module.exports = {
-    entry: path.join(__dirname, 'srcjs', '%s.js'),
+    entry: path.join(__dirname, 'srcjs', '${name}.js'),
     output: {
         path: path.join(__dirname, 'inst', 'htmlwidgets'),
-        filename: '%s.js'
+        filename: '${name}.js'
     },
     module: {
         rules: [

inst/www/react-tools/react-tools.js

@@ -20,7 +20,7 @@ window.reactR = (function () {
                 args.push(tag.children[i]);
             }
         }
-        return React.createElement.apply(null, args);
+        return React.createElement.apply(React, args);
     }
 
     var defaultOptions = {
@@ -46,12 +46,19 @@ window.reactR = (function () {
 
     function formatDimension(dim, options) {
         if (options.appendPx) {
-            return dim.toString() + 'px';
+            return dim + 'px';
         } else {
             return dim;
         }
     }
 
+    function isTag(value) {
+        return (typeof value === 'object')
+            && value.hasOwnProperty('name')
+            && value.hasOwnProperty('attribs')
+            && value.hasOwnProperty('children');
+    }
+
     /**
      * Creates an HTMLWidget that is updated by rendering a React component.
      * React component constructors are made available by specifying them by
@@ -67,15 +74,16 @@ window.reactR = (function () {
             name: name,
             type: type,
             factory: function (el, width, height) {
-                var lastValue;
-                renderValue = (function (value) {
-                    if (actualOptions.renderOnResize) {
-                        value.tag.attribs[actualOptions["widthProperty"]] = formatDimension(width);
-                        value.tag.attribs[actualOptions["heightProperty"]] = formatDimension(height);
-                        lastValue = value;
-                    }
-                    ReactDOM.render(hydrate(components, value.tag), el);
-                });
+                var lastValue,
+                    renderValue = (function (value) {
+                        // TODO Handle strings naturally
+                        if (actualOptions.renderOnResize) {
+                            value.tag.attribs[actualOptions["widthProperty"]] = formatDimension(width);
+                            value.tag.attribs[actualOptions["heightProperty"]] = formatDimension(height);
+                            lastValue = value;
+                        }
+                        ReactDOM.render(hydrate(components, value.tag), el);
+                    });
                 return {
                     renderValue: renderValue,
                     resize: function (newWidth, newHeight) {
@@ -92,6 +100,12 @@ window.reactR = (function () {
 
     return {
         reactWidget: reactWidget,
-        hydrate: hydrate
+        hydrate: hydrate,
+        __internal: {
+            defaultOptions: defaultOptions,
+            mergeOptions: mergeOptions,
+            formatDimension: formatDimension,
+            isTag: isTag
+        }
     };
 })()