diff --git a/R/combine_widgets.R b/R/combine_widgets.R
index 5265bec..7bde3a9 100644
--- a/R/combine_widgets.R
+++ b/R/combine_widgets.R
@@ -1,338 +1,338 @@
-#Copyright © 2016 RTE Réseau de transport d’électricité
-
-#' Combine several interactive plots
-#'
-#' This function combines different htmlwidgets in a unique view.
-#'
-#' @param ... htmlwidgets to combine. If this list contains objects that are not
-#'   htmlwidgets, the function tries to convert them into a character string which
-#'   is interpreted as html content.
-#' @param list Instead of directly passing htmlwidgets to the function, one can
-#'   pass a list of htmlwidgets and objects coercible to character. In particular,
-#'   it can be usefull if multiple htmlwidgets have been generated using a loop
-#'   function like \code{\link[base]{lapply}}.
-#' @param nrow Number of rows of the layout. If \code{NULL}, the function will
-#'   automatically take a value such that are at least as many cells in the
-#'   layout as the number of htmlwidgets.
-#' @param ncol Number of columns of the layout.If \code{NULL}, the function will
-#'   automatically take a value such that are at least as many cells in the
-#'   layout as the number of htmlwidgets.
-#' @param title Title of the view.
-#' @param rowsize This argument controls the relative size of each row. For
-#'   instance, if the layout has two rows and \code{rowsize = c(2,1)}, then the
-#'   width of the first row will be twice the one of the second one. This
-#'   argument is recycled to fit the number of rows.
-#' @param colsize Same as rowsize but for the height of the columns of the
-#'   layout.
-#' @param byrow If \code{TRUE}, then the layout is filled by row. Else it is
-#'   filled by column.
-#' @param titleCSS A character containing css properties to modify the
-#'   appearance of the title of the view.
-#' @param header Content to display between the title and the combined widgets.
-#'   It can be a single character string or html tags.
-#' @param footer Content to display under the combined widgets. It can be a
-#'   single character string or html tags.
-#' @param leftCol Content to display on the left of the combined widgets. It can
-#'   be a single character string or html tags.
-#' @param rightCol Content to display on the right the combined widgets. It can
-#'   be a single character string or html tags.
-#'
-#' @param width Total width of the layout (optional, defaults to automatic
-#'   sizing).
-#' @param height Total height of the layout (optional, defaults to automatic
-#'   sizing).
-#' @return A htmlwidget object of class \code{combineWidget}. Individual widgets
-#'   are stored in element \code{widgets} and can be extracted or updated. This
-#'   is useful when a function returns a \code{combineWidgets} object but user
-#'   wants to keep only one widget or to update one of them (see examples).
-#'
-#' @details The function only allows table like layout : each row has the same
-#' number of columns and reciprocally. But it is possible to create more complex
-#' layout by nesting combined htmlwidgets. (see examples)
-#'
-#' @examples
-#' if (require(plotly)) {
-#'   data(iris)
-#'
-#'   combineWidgets(title = "The Iris dataset",
-#'     plot_ly(iris, x = ~Sepal.Length, type = "histogram", nbinsx = 20),
-#'     plot_ly(iris, x = ~Sepal.Width, type = "histogram", nbinsx = 20),
-#'     plot_ly(iris, x = ~Petal.Length, type = "histogram", nbinsx = 20),
-#'     plot_ly(iris, x = ~Petal.Width, type = "histogram", nbinsx = 20)
-#'   )
-#'
-#'   # Create a more complex layout by nesting combinedWidgets
-#'   combineWidgets(title = "The iris data set: sepals", ncol = 2, colsize = c(2,1),
-#'     plot_ly(iris, x = ~Sepal.Length, y = ~Sepal.Width, type = "scatter",
-#'             mode = "markers", color = ~Species),
-#'     combineWidgets(
-#'       plot_ly(iris, x = ~Sepal.Length, type = "histogram", nbinsx = 20),
-#'       plot_ly(iris, x = ~Sepal.Width, type = "histogram", nbinsx = 20)
-#'     )
-#'   )
-#'
-#'   # combineWidgets can also be used on a single widget to easily add to it a
-#'   # title and a footer.
-#'   require(shiny)
-#'   comments <- tags$div(
-#'     "Wow this plot is so ",
-#'     tags$span("amazing!!", style = "color:red;font-size:36px")
-#'   )
-#'
-#'   combineWidgets(
-#'     plot_ly(iris, x = ~Sepal.Length, type = "histogram", nbinsx = 20),
-#'     title = "Distribution of Sepal Length",
-#'     footer = comments
-#'   )
-#'
-#'   # It is also possible to combine htmlwidgets with text or other html elements
-#'   myComment <- tags$div(
-#'     style="height:100%;background-color:#eee;padding:10px;box-sizing:border-box",
-#'     tags$h2("Comment"),
-#'     tags$hr(),
-#'     "Here is a very clever comment about the awesome graphics you just saw."
-#'   )
-#'   combineWidgets(
-#'     plot_ly(iris, x = ~Sepal.Length, type = "histogram", nbinsx = 20),
-#'     plot_ly(iris, x = ~Sepal.Width, type = "histogram", nbinsx = 20),
-#'     plot_ly(iris, x = ~Petal.Length, type = "histogram", nbinsx = 20),
-#'     myComment
-#'   )
-#'
-#'   # Updating individual widgets.
-#'   myWidget <- combineWidgets(
-#'     plot_ly(iris, x = ~Sepal.Length, type = "histogram", nbinsx = 20),
-#'     plot_ly(iris, x = ~Sepal.Width, type = "histogram", nbinsx = 20),
-#'     ncol = 2
-#'   )
-#'   myWidget
-#'
-#'
-#'   myWidget$widgets[[1]] <- myWidget$widgets[[1]] %>%
-#'     layout(title = "Histogram of Sepal Length")
-#'
-#'   myWidget$widgets[[2]] <- myWidget$widgets[[2]] %>%
-#'     layout(title = "Histogram of Sepal Width")
-#'
-#'   myWidget
-#'
-#'
-#'   # Instead of passing directly htmlwidgets to the function, one can pass
-#'   # a list containing htmlwidgets. This is especially useful when the widgets
-#'   # are generated using a loop function like "lapply" or "replicate".
-#'   #
-#'   # The following code generates a list of 12 histograms and use combineWidgets
-#'   # to display them.
-#'   samples <- replicate(12, plot_ly(x = rnorm(100), type = "histogram", nbinsx = 20),
-#'                        simplify = FALSE)
-#'   combineWidgets(list = samples, title = "12 samples of the same distribution")
-#' }
-#'
-#' @export
-#' @importFrom htmltools tagGetAttribute
-combineWidgets <- function(..., list = NULL, nrow = NULL, ncol = NULL, title = NULL,
-                           rowsize = 1, colsize = 1, byrow = TRUE,
-                           titleCSS = "",
-                           header = NULL, footer = NULL,
-                           leftCol = NULL, rightCol = NULL,
-                           width = NULL, height = NULL) {
-
-  widgets <- c(list(...), list)
-  if (length(widgets) == 0) return(combineWidgets(""))
-
-  # create empty widget
-  res <- htmlwidgets::createWidget(
-    name = 'combineWidgets',
-    x = NULL,
-    width = width,
-    height = height,
-    package = 'manipulateWidget',
-    sizingPolicy = htmlwidgets::sizingPolicy(
-      browser.fill = TRUE
-    ),
-    preRenderHook = preRenderCombinedWidgets
-  )
-
-  # Add dependencies of embedded widgets or shiny tags
-  # This works through the widgets recursively, in case
-  # we were passed a shiny.tag.list or other list of
-  # non-widgets.
-
-  getDeps <- function(x) {
-    if (!is.null(attr(x, "package")))
-      append(tryCatch(getDependency(class(x)[1], attr(x, "package")),
-                      error = function(e) NULL), x$dependencies)
-    else if (!is.null(attr(x, "html_dependencies")))
-      attr(x, "html_dependencies")
-    else if (is.list(x))
-      do.call(c, lapply(x, getDeps))
-  }
-  deps <- c(getDeps(widgets),
-            getDeps(header),
-            getDeps(footer),
-            getDeps(leftCol),
-            getDeps(rightCol))
-
-  res$dependencies <- deps
-
-  # Add widget list and parameters
-  res$widgets <- widgets
-  res$params <- list(
-    nrow = nrow,
-    ncol = ncol,
-    title = title,
-    rowsize = rowsize,
-    colsize = colsize,
-    byrow = byrow,
-    titleCSS = titleCSS,
-    header = header,
-    footer = footer,
-    leftCol = leftCol,
-    rightCol = rightCol,
-    width = width,
-    height = height
-  )
-
-  res
-}
-
-#' Shiny bindings for combineWidgets
-#'
-#' Output and render functions for using combineWidgets within Shiny
-#' applications and interactive Rmd documents.
-#'
-#' @param outputId output variable to read from
-#' @param width,height Must be a valid CSS unit (like \code{'100\%'},
-#'   \code{'400px'}, \code{'auto'}) or a number, which will be coerced to a
-#'   string and have \code{'px'} appended.
-#' @param expr An expression that generates a combineWidgets
-#' @param env The environment in which to evaluate \code{expr}.
-#' @param quoted Is \code{expr} a quoted expression (with \code{quote()})? This
-#'   is useful if you want to save an expression in a variable.
-#'
-#' @name combineWidgets-shiny
-#'
-#' @export
-combineWidgetsOutput <- function(outputId, width = '100%', height = '400px'){
-  htmlwidgets::shinyWidgetOutput(outputId, 'combineWidgets', width, height, package = 'manipulateWidget')
-}
-
-#' @rdname combineWidgets-shiny
-#' @export
-renderCombineWidgets <- function(expr, env = parent.frame(), quoted = FALSE) {
-  if (!quoted) { expr <- substitute(expr) } # force quoted
-  htmlwidgets::shinyRenderWidget(expr, combineWidgetsOutput, env, quoted = TRUE)
-}
-
-# Private function used to prerender a combinedWidgets object
-preRenderCombinedWidgets <- function(x) {
-
-  hasCrosstalkInputs <- any(unlist(lapply(x$widgets, isCrosstalkInput)))
-
-  widgets <- lapply(unname(x$widgets), function(w) {
-    if (is.atomic(w)) return(structure(list(x = as.character(w)), class = "html"))
-    if (is.null(w$preRenderHook)) {
-      if (is(w, "htmlwidget")) return(w)
-      else return(structure(list(x = as.character(w)), class = "html"))
-    }
-    w$preRenderHook(w)
-  })
-  nwidgets <- length(x$widgets)
-
-  # Get number of rows and cols
-  dims <- .getRowAndCols(nwidgets, x$params$nrow, x$params$ncol)
-  nrow <- dims$nrow
-  ncol <- dims$ncol
-
-  ncells <- nrow * ncol
-
-  # Relative size of rows and cols
-  rowsize <- rep(x$params$rowsize, length.out = nrow)
-  colsize <- rep(x$params$colsize, length.out = ncol)
-
-  # Get the html ID of each widget
-  if (!is.null(names(x$widgets))) {
-    elementId <- names(x$widgets)
-    elementId[elementId == ""] <- "widget"
-    elementId <- make.unique(elementId)
-  } else {
-    elementId <- sapply(widgets[1:ncells], function(w) {
-      if (is.null(w)) res <- NULL
-      else res <- w$elementId
-
-      if (is.null(res)) res <- paste0("widget", floor(stats::runif(1, max = 1e9)))
-
-      res
-    })
-  }
-
-  # Get the HTML class for each widget, plus "cw-widget"
-  elementClass <- sapply(widgets[1:ncells], function(w) {
-    result <- NULL
-    if (inherits(w, "htmlwidget"))
-      result <- class(w)[1]
-    else if (inherits(w, "shiny.tag"))
-      result <- tagGetAttribute(w, "class")
-    paste(result, "cw-widget")
-  })
-
-  # Construct the html of the combined widget
-  dirClass <- ifelse(x$params$byrow, "cw-by-row", "cw-by-col")
-
-  widgetEL <- mapply(
-    function(id, size, class) {
-      sprintf('<div class="cw-col" style="flex:%s;-webkit-flex:%s">
-              <div id="%s" class="%s" style="width:100%%;height:100%%"></div>
-              </div>',
-              size, size, id, class)
-    },
-    id = elementId,
-    size = rep(colsize, length.out = ncells),
-    class = elementClass
-  )
-
-  rowsEl <- lapply(1:nrow, function(i) {
-    content <- widgetEL[((i-1) * ncol + 1):(i * ncol)]
-    sprintf('<div class="cw-row %s" style="flex:%s;-webkit-flex:%s">%s</div>',
-            dirClass, rowsize[i], rowsize[i], paste(content, collapse = ""))
-  })
-
-  content <- sprintf('<div class="cw-content %s">%s</div>',
-                     dirClass, paste(rowsEl, collapse = ""))
-
-  if(!is.null(x$params$title) && !x$params$title == "") {
-    titleEl <- sprintf('<div><h2 class="cw-title" style="%s">%s</h2></div>',
-                       x$params$titleCSS, x$params$title)
-  } else {
-    titleEl <- ""
-  }
-
-  if (is.null(x$params$footer)) footer <- ""
-  else footer <- paste0("<div>", x$params$footer, "</div>")
-  if (is.null(x$params$header)) header <- ""
-  else header <- paste0("<div>", x$params$header, "</div>")
-  if (is.null(x$params$leftCol)) leftCol <- ""
-  else leftCol <- paste0("<div style='height:100%'>", x$params$leftCol, "</div>")
-  if (is.null(x$params$rightCol)) rightCol <- ""
-  else rightCol <- paste0("<div style='height:100%'>", x$params$rightCol, "</div>")
-
-  html <- sprintf('<div class="cw-container">%s%s<div class="cw-subcontainer">%s%s%s</div>%s</div>',
-                  titleEl, header, leftCol, content, rightCol, footer)
-
-  data <- lapply(widgets, function(w) w$x)
-  widgetType <- sapply(widgets, function(w) class(w)[1])
-
-  x$x <- list(data = data, widgetType = widgetType, elementId = elementId, html = html,
-              hasCrosstalkInputs = hasCrosstalkInputs);
-
-  x
-}
-
-# Check whether a widget is a crosstalk-package input, which will need special
-# initialization within combineWidgets()
-
-isCrosstalkInput <- function(w) {
-  inherits(w, "shiny.tag") &&
-    !is.null(w$attribs) &&
-    grepl("crosstalk-input", w$attribs$class)
-}
+#Copyright © 2016 RTE Réseau de transport d’électricité
+
+#' Combine several interactive plots
+#'
+#' This function combines different htmlwidgets in a unique view.
+#'
+#' @param ... htmlwidgets to combine. If this list contains objects that are not
+#'   htmlwidgets, the function tries to convert them into a character string which
+#'   is interpreted as html content.
+#' @param list Instead of directly passing htmlwidgets to the function, one can
+#'   pass a list of htmlwidgets and objects coercible to character. In particular,
+#'   it can be usefull if multiple htmlwidgets have been generated using a loop
+#'   function like \code{\link[base]{lapply}}.
+#' @param nrow Number of rows of the layout. If \code{NULL}, the function will
+#'   automatically take a value such that are at least as many cells in the
+#'   layout as the number of htmlwidgets.
+#' @param ncol Number of columns of the layout.If \code{NULL}, the function will
+#'   automatically take a value such that are at least as many cells in the
+#'   layout as the number of htmlwidgets.
+#' @param title Title of the view.
+#' @param rowsize This argument controls the relative size of each row. For
+#'   instance, if the layout has two rows and \code{rowsize = c(2,1)}, then the
+#'   width of the first row will be twice the one of the second one. This
+#'   argument is recycled to fit the number of rows.
+#' @param colsize Same as rowsize but for the height of the columns of the
+#'   layout.
+#' @param byrow If \code{TRUE}, then the layout is filled by row. Else it is
+#'   filled by column.
+#' @param titleCSS A character containing css properties to modify the
+#'   appearance of the title of the view.
+#' @param header Content to display between the title and the combined widgets.
+#'   It can be a single character string or html tags.
+#' @param footer Content to display under the combined widgets. It can be a
+#'   single character string or html tags.
+#' @param leftCol Content to display on the left of the combined widgets. It can
+#'   be a single character string or html tags.
+#' @param rightCol Content to display on the right the combined widgets. It can
+#'   be a single character string or html tags.
+#'
+#' @param width Total width of the layout (optional, defaults to automatic
+#'   sizing).
+#' @param height Total height of the layout (optional, defaults to automatic
+#'   sizing).
+#' @return A htmlwidget object of class \code{combineWidget}. Individual widgets
+#'   are stored in element \code{widgets} and can be extracted or updated. This
+#'   is useful when a function returns a \code{combineWidgets} object but user
+#'   wants to keep only one widget or to update one of them (see examples).
+#'
+#' @details The function only allows table like layout : each row has the same
+#' number of columns and reciprocally. But it is possible to create more complex
+#' layout by nesting combined htmlwidgets. (see examples)
+#'
+#' @examples
+#' if (require(plotly)) {
+#'   data(iris)
+#'
+#'   combineWidgets(title = "The Iris dataset",
+#'     plot_ly(iris, x = ~Sepal.Length, type = "histogram", nbinsx = 20),
+#'     plot_ly(iris, x = ~Sepal.Width, type = "histogram", nbinsx = 20),
+#'     plot_ly(iris, x = ~Petal.Length, type = "histogram", nbinsx = 20),
+#'     plot_ly(iris, x = ~Petal.Width, type = "histogram", nbinsx = 20)
+#'   )
+#'
+#'   # Create a more complex layout by nesting combinedWidgets
+#'   combineWidgets(title = "The iris data set: sepals", ncol = 2, colsize = c(2,1),
+#'     plot_ly(iris, x = ~Sepal.Length, y = ~Sepal.Width, type = "scatter",
+#'             mode = "markers", color = ~Species),
+#'     combineWidgets(
+#'       plot_ly(iris, x = ~Sepal.Length, type = "histogram", nbinsx = 20),
+#'       plot_ly(iris, x = ~Sepal.Width, type = "histogram", nbinsx = 20)
+#'     )
+#'   )
+#'
+#'   # combineWidgets can also be used on a single widget to easily add to it a
+#'   # title and a footer.
+#'   require(shiny)
+#'   comments <- tags$div(
+#'     "Wow this plot is so ",
+#'     tags$span("amazing!!", style = "color:red;font-size:36px")
+#'   )
+#'
+#'   combineWidgets(
+#'     plot_ly(iris, x = ~Sepal.Length, type = "histogram", nbinsx = 20),
+#'     title = "Distribution of Sepal Length",
+#'     footer = comments
+#'   )
+#'
+#'   # It is also possible to combine htmlwidgets with text or other html elements
+#'   myComment <- tags$div(
+#'     style="height:100%;background-color:#eee;padding:10px;box-sizing:border-box",
+#'     tags$h2("Comment"),
+#'     tags$hr(),
+#'     "Here is a very clever comment about the awesome graphics you just saw."
+#'   )
+#'   combineWidgets(
+#'     plot_ly(iris, x = ~Sepal.Length, type = "histogram", nbinsx = 20),
+#'     plot_ly(iris, x = ~Sepal.Width, type = "histogram", nbinsx = 20),
+#'     plot_ly(iris, x = ~Petal.Length, type = "histogram", nbinsx = 20),
+#'     myComment
+#'   )
+#'
+#'   # Updating individual widgets.
+#'   myWidget <- combineWidgets(
+#'     plot_ly(iris, x = ~Sepal.Length, type = "histogram", nbinsx = 20),
+#'     plot_ly(iris, x = ~Sepal.Width, type = "histogram", nbinsx = 20),
+#'     ncol = 2
+#'   )
+#'   myWidget
+#'
+#'
+#'   myWidget$widgets[[1]] <- myWidget$widgets[[1]] %>%
+#'     layout(title = "Histogram of Sepal Length")
+#'
+#'   myWidget$widgets[[2]] <- myWidget$widgets[[2]] %>%
+#'     layout(title = "Histogram of Sepal Width")
+#'
+#'   myWidget
+#'
+#'
+#'   # Instead of passing directly htmlwidgets to the function, one can pass
+#'   # a list containing htmlwidgets. This is especially useful when the widgets
+#'   # are generated using a loop function like "lapply" or "replicate".
+#'   #
+#'   # The following code generates a list of 12 histograms and use combineWidgets
+#'   # to display them.
+#'   samples <- replicate(12, plot_ly(x = rnorm(100), type = "histogram", nbinsx = 20),
+#'                        simplify = FALSE)
+#'   combineWidgets(list = samples, title = "12 samples of the same distribution")
+#' }
+#'
+#' @export
+#' @importFrom htmltools tagGetAttribute
+combineWidgets <- function(..., list = NULL, nrow = NULL, ncol = NULL, title = NULL,
+                           rowsize = 1, colsize = 1, byrow = TRUE,
+                           titleCSS = "",
+                           header = NULL, footer = NULL,
+                           leftCol = NULL, rightCol = NULL,
+                           width = NULL, height = NULL) {
+
+  widgets <- c(list(...), list)
+  if (length(widgets) == 0) return(combineWidgets(""))
+
+  # create empty widget
+  res <- htmlwidgets::createWidget(
+    name = 'combineWidgets',
+    x = NULL,
+    width = width,
+    height = height,
+    package = 'manipulateWidget',
+    sizingPolicy = htmlwidgets::sizingPolicy(
+      browser.fill = TRUE
+    ),
+    preRenderHook = preRenderCombinedWidgets
+  )
+
+  # Add dependencies of embedded widgets or shiny tags
+  # This works through the widgets recursively, in case
+  # we were passed a shiny.tag.list or other list of
+  # non-widgets.
+
+  getDeps <- function(x) {
+    if (!is.null(attr(x, "package")))
+      append(tryCatch(getDependency(class(x)[1], attr(x, "package")),
+                      error = function(e) NULL), x$dependencies)
+    else if (!is.null(attr(x, "html_dependencies")))
+      attr(x, "html_dependencies")
+    else if (is.list(x))
+      do.call(c, lapply(x, getDeps))
+  }
+  deps <- c(getDeps(widgets),
+            getDeps(header),
+            getDeps(footer),
+            getDeps(leftCol),
+            getDeps(rightCol))
+
+  res$dependencies <- deps
+
+  # Add widget list and parameters
+  res$widgets <- widgets
+  res$params <- list(
+    nrow = nrow,
+    ncol = ncol,
+    title = title,
+    rowsize = rowsize,
+    colsize = colsize,
+    byrow = byrow,
+    titleCSS = titleCSS,
+    header = header,
+    footer = footer,
+    leftCol = leftCol,
+    rightCol = rightCol,
+    width = width,
+    height = height
+  )
+
+  res
+}
+
+#' Shiny bindings for combineWidgets
+#'
+#' Output and render functions for using combineWidgets within Shiny
+#' applications and interactive Rmd documents.
+#'
+#' @param outputId output variable to read from
+#' @param width,height Must be a valid CSS unit (like \code{'100\%'},
+#'   \code{'400px'}, \code{'auto'}) or a number, which will be coerced to a
+#'   string and have \code{'px'} appended.
+#' @param expr An expression that generates a combineWidgets
+#' @param env The environment in which to evaluate \code{expr}.
+#' @param quoted Is \code{expr} a quoted expression (with \code{quote()})? This
+#'   is useful if you want to save an expression in a variable.
+#'
+#' @name combineWidgets-shiny
+#'
+#' @export
+combineWidgetsOutput <- function(outputId, width = '100%', height = '400px'){
+  htmlwidgets::shinyWidgetOutput(outputId, 'combineWidgets', width, height, package = 'manipulateWidget')
+}
+
+#' @rdname combineWidgets-shiny
+#' @export
+renderCombineWidgets <- function(expr, env = parent.frame(), quoted = FALSE) {
+  if (!quoted) { expr <- substitute(expr) } # force quoted
+  htmlwidgets::shinyRenderWidget(expr, combineWidgetsOutput, env, quoted = TRUE)
+}
+
+# Private function used to prerender a combinedWidgets object
+preRenderCombinedWidgets <- function(x) {
+
+  hasCrosstalkInputs <- any(unlist(lapply(x$widgets, isCrosstalkInput)))
+
+  widgets <- lapply(unname(x$widgets), function(w) {
+    if (is.atomic(w)) return(structure(list(x = as.character(w)), class = "html"))
+    if (is.null(w$preRenderHook)) {
+      if (is(w, "htmlwidget")) return(w)
+      else return(structure(list(x = as.character(w)), class = "html"))
+    }
+    w$preRenderHook(w)
+  })
+  nwidgets <- length(x$widgets)
+
+  # Get number of rows and cols
+  dims <- .getRowAndCols(nwidgets, x$params$nrow, x$params$ncol)
+  nrow <- dims$nrow
+  ncol <- dims$ncol
+
+  ncells <- nrow * ncol
+
+  # Relative size of rows and cols
+  rowsize <- rep(x$params$rowsize, length.out = nrow)
+  colsize <- rep(x$params$colsize, length.out = ncol)
+
+  # Get the html ID of each widget
+  if (!is.null(names(x$widgets))) {
+    elementId <- names(x$widgets)
+    elementId[elementId == ""] <- "widget"
+    elementId <- make.unique(elementId)
+  } else {
+    elementId <- sapply(widgets[1:ncells], function(w) {
+      if (is.null(w)) res <- NULL
+      else res <- w$elementId
+
+      if (is.null(res)) res <- paste0("widget", floor(stats::runif(1, max = 1e9)))
+
+      res
+    })
+  }
+
+  # Get the HTML class for each widget, plus "cw-widget"
+  elementClass <- sapply(widgets[1:ncells], function(w) {
+    result <- NULL
+    if (inherits(w, "htmlwidget"))
+      result <- class(w)[1]
+    else if (inherits(w, "shiny.tag"))
+      result <- tagGetAttribute(w, "class")
+    paste(result, "cw-widget", "html-widget-static-bound")
+  })
+
+  # Construct the html of the combined widget
+  dirClass <- ifelse(x$params$byrow, "cw-by-row", "cw-by-col")
+
+  widgetEL <- mapply(
+    function(id, size, class) {
+      sprintf('<div class="cw-col" style="flex:%s;-webkit-flex:%s">
+              <div id="%s" class="%s" style="width:100%%;height:100%%"></div>
+              </div>',
+              size, size, id, class)
+    },
+    id = elementId,
+    size = rep(colsize, length.out = ncells),
+    class = elementClass
+  )
+
+  rowsEl <- lapply(1:nrow, function(i) {
+    content <- widgetEL[((i-1) * ncol + 1):(i * ncol)]
+    sprintf('<div class="cw-row %s" style="flex:%s;-webkit-flex:%s">%s</div>',
+            dirClass, rowsize[i], rowsize[i], paste(content, collapse = ""))
+  })
+
+  content <- sprintf('<div class="cw-content %s">%s</div>',
+                     dirClass, paste(rowsEl, collapse = ""))
+
+  if(!is.null(x$params$title) && !x$params$title == "") {
+    titleEl <- sprintf('<div><h2 class="cw-title" style="%s">%s</h2></div>',
+                       x$params$titleCSS, x$params$title)
+  } else {
+    titleEl <- ""
+  }
+
+  if (is.null(x$params$footer)) footer <- ""
+  else footer <- paste0("<div>", x$params$footer, "</div>")
+  if (is.null(x$params$header)) header <- ""
+  else header <- paste0("<div>", x$params$header, "</div>")
+  if (is.null(x$params$leftCol)) leftCol <- ""
+  else leftCol <- paste0("<div style='height:100%'>", x$params$leftCol, "</div>")
+  if (is.null(x$params$rightCol)) rightCol <- ""
+  else rightCol <- paste0("<div style='height:100%'>", x$params$rightCol, "</div>")
+
+  html <- sprintf('<div class="cw-container">%s%s<div class="cw-subcontainer">%s%s%s</div>%s</div>',
+                  titleEl, header, leftCol, content, rightCol, footer)
+
+  data <- lapply(widgets, function(w) w$x)
+  widgetType <- sapply(widgets, function(w) class(w)[1])
+
+  x$x <- list(data = data, widgetType = widgetType, elementId = elementId, html = html,
+              hasCrosstalkInputs = hasCrosstalkInputs);
+
+  x
+}
+
+# Check whether a widget is a crosstalk-package input, which will need special
+# initialization within combineWidgets()
+
+isCrosstalkInput <- function(w) {
+  inherits(w, "shiny.tag") &&
+    !is.null(w$attribs) &&
+    grepl("crosstalk-input", w$attribs$class)
+}