Primitive implementatin of text and image inclusion

DESCRIPTION

@@ -16,7 +16,8 @@ Imports:
     knitr,
     flexdashboard,
     yaml,
-    assertive.sets
+    assertive.sets,
+    stringr
 Suggests: 
     highcharter,
     plotly,

R/components.R

-#' Method to add a component to a page of an i2dashboard
+#' Method to add a component to a page of an i2dashboard.
+#'
+#' Components can be created by evaluating a function, or by including a text or image file.
+#' The function tries to guess the intended usage by applying regular expressions to the argument \code{component} (see below for details).
+#'
+#' @section Adding a component by evaluating a function:
+#' If the argument \code{component} is a valid function name, the function will be called and its return value is used as component content.
+#'
+#' @section Adding plain text as a component:
+#' If the argument \code{component} ends with \code{.md} or \code{.txt}, the function will try to open a file and use its content as the components content.
+#'
+#' @section Adding images as a component:
+#' If the argument \code{component} end matches \code{\\.[png|jpg|jpeg|gif]}, the function will try to include an image as the components content.
 #'
 #' @param dashboard A \linkS4class{i2dash::i2dashboard}.
 #' @param page The name of the page to add the component to.
-#' @param component The name of the component.
+#' @param component The name of a function of a path to a file.
+#' @param copy Whether or not to copy images to \code{dashboard@datadir}.
 #' @param ... Additional parameters passed to the components render function.
 #'
-#' @rdname i2dashboard-methods
+#' @rdname add-component
 #' @export
 setMethod("add_component",
           signature = signature(dashboard = "i2dashboard", component = "character"),
-          function(dashboard, component, page = "default", ...) {
-  name <- .create_page_name(page)
-  if (!(name %in% names(dashboard@pages))) {
-    warning(sprintf("i2dashboard dashboard does not contain a page named '%s'", name))
-    return(dashboard)
-  }
+          function(dashboard, component, page = "default", copy = FALSE, ...) {
+            # Logic to guess intended usage
+            mode <- "function"
+            if(stringr::str_detect(tolower(component), "\\.[md|txt]+$")) {
+              mode <- "text"
+            }
+            if(stringr::str_detect(tolower(component), "\\.[png|jpg|jpeg|gif]+$")) {
+              if(copy) {
+                location <- file.path(dashboard@datadir, basename(component))
+                file.copy(component, location)
+                component <- location
+              }
+              mode <- "image"
+            }
 
-  if(length(dashboard@pages[[name]]$components) + 1 > dashboard@pages[[name]]$max_components) {
-    warning(sprintf("Not enough space left on page '%s'", name))
-    return(dashboard)
-  }
+            # Create page
+            name <- .create_page_name(page)
+            if (!(name %in% names(dashboard@pages))) {
+              warning(sprintf("i2dashboard dashboard does not contain a page named '%s'", name))
+              return(dashboard)
+            }
 
-  pn <- strsplit(component, "::")[[1]]
-  eval_function <- if(length(pn) == 1) {
-    get(pn[[1]], envir = asNamespace("i2dash"), mode = "function")
-  } else {
-    get(pn[[2]], envir = asNamespace(pn[[1]]), mode = "function")
-  }
+            if(length(dashboard@pages[[name]]$components) + 1 > dashboard@pages[[name]]$max_components) {
+              warning(sprintf("Not enough space left on page '%s'", name))
+              return(dashboard)
+            }
 
-  component <- do.call(eval_function, args = list(dashboard, ...))
+            if(mode == "function") {
+              pn <- strsplit(component, "::")[[1]]
+              eval_function <- if(length(pn) == 1) {
+                get(pn[[1]], envir = asNamespace("i2dash"), mode = "function")
+              } else {
+                get(pn[[2]], envir = asNamespace(pn[[1]]), mode = "function")
+              }
+            }
 
-  if(is.list(component)) {
-    assertive.sets::is_subset(c("appendix", "component", "sidebar"), names(component))
-    dashboard@pages[[name]]$components <- append(dashboard@pages[[name]]$components, component$component)
-    dashboard@pages[[name]]$sidebar <- paste0(dashboard@pages[[name]]$sidebar, component$sidebar)
-    # ToDo: Handle appendix
-  } else {
-    dashboard@pages[[name]]$components <- append(dashboard@pages[[name]]$components, component)
-  }
-  return(dashboard)
-})
+            component <- switch(mode,
+              "function" = do.call(eval_function, args = list(dashboard, ...)),
+              "text" = do.call("render_text", args = list(component, ...)),
+              "image" = do.call("render_image", args = list(component, ...)))
+
+            if(is.list(component)) {
+              assertive.sets::is_subset(c("appendix", "component", "sidebar"), names(component))
+              dashboard@pages[[name]]$components <- append(dashboard@pages[[name]]$components, component$component)
+              dashboard@pages[[name]]$sidebar <- paste0(dashboard@pages[[name]]$sidebar, component$sidebar)
+              # ToDo: Handle appendix
+            } else {
+              dashboard@pages[[name]]$components <- append(dashboard@pages[[name]]$components, component)
+            }
+            return(dashboard)
+          })
 
 #' Method to download embed files into an Rmd-file
 #'
@@ -47,8 +80,40 @@ setMethod("add_component",
 #' @param ... Additional parameters.
 #'
 #' @export
-embed_var = function(x, ...) {
+embed_var <- function(x, ...) {
   f = tempfile(fileext = '.csv')
   write.csv(x, f)
   xfun::embed_file(f, text = 'Download full data as .csv', ...)
 }
+
+#' Method to embed content from a text file in a component
+#'
+#' @param file The file containing the text content.
+#' @param title The components title.
+#'
+#' @return A character string containing the evaluated component
+render_text <- function(file, title = NULL) {
+  content <- readLines(con = file)
+  knitr::knit_expand(file = system.file("templates", "text_component.Rmd", package = "i2dash"),
+                     delim = c("<%", "%>"),
+                     content = content,
+                     title = title)
+}
+
+#' Method to embed an image file in a component
+#'
+#' @param image The path to the image file.
+#' @param image_alt_text The alt text of the image.
+#' @param title The components title.
+#'
+#' @return A character string containing the evaluated component
+render_image <- function(image, image_alt_text = NULL, title = NULL) {
+  if(is.null(image_alt_text)) {
+    image_alt_text <- image
+  }
+  knitr::knit_expand(file = system.file("templates", "image_component.Rmd", package = "i2dash"),
+                     delim = c("<%", "%>"),
+                     image = image,
+                     image_alt_text = image_alt_text,
+                     title = title)
+}

inst/templates/image_component.Rmd

+### <% title %>
+
+![<% image_alt_text %>](<% image %>)

inst/templates/text_component.Rmd

+### <% title %>
+
+<% content %>

man/add-component.Rd

+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/components.R
+\docType{methods}
+\name{add_component,i2dashboard,character-method}
+\alias{add_component,i2dashboard,character-method}
+\title{Method to add a component to a page of an i2dashboard.}
+\usage{
+\S4method{add_component}{i2dashboard,character}(dashboard, component,
+  page = "default", copy = FALSE, ...)
+}
+\arguments{
+\item{dashboard}{A \linkS4class{i2dash::i2dashboard}.}
+
+\item{component}{The name of a function of a path to a file.}
+
+\item{page}{The name of the page to add the component to.}
+
+\item{copy}{Whether or not to copy images to \code{dashboard@datadir}.}
+
+\item{...}{Additional parameters passed to the components render function.}
+}
+\description{
+Components can be created by evaluating a function, or by including a text or image file.
+The function tries to guess the intended usage by applying regular expressions to the argument \code{component} (see below for details).
+}
+\section{Adding a component by evaluating a function}{
+
+If the argument \code{component} is a valid function name, the function will be called and its return value is used as component content.
+}
+
+\section{Adding plain text as a component}{
+
+If the argument \code{component} ends with \code{.md} or \code{.txt}, the function will try to open a file and use its content as the components content.
+}
+
+\section{Adding images as a component}{
+
+If the argument \code{component} end matches \code{\\.[png|jpg|jpeg|gif]}, the function will try to include an image as the components content.
+}
+

man/i2dashboard-methods.Rd

 % Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/assemble.R, R/components.R, R/pages.R
+% Please edit documentation in R/assemble.R, R/pages.R
 \docType{methods}
 \name{assemble,i2dashboard-method}
 \alias{assemble,i2dashboard-method}
-\alias{add_component,i2dashboard,character-method}
 \alias{add_page,i2dashboard-method}
 \alias{remove_page,i2dashboard-method}
 \title{Method to assemble a dashboard to a Rmd file.}
@@ -12,9 +11,6 @@
   pages = names(dashboard@pages), file = dashboard@file,
   exclude = NULL, render = FALSE, ...)
 
-\S4method{add_component}{i2dashboard,character}(dashboard, component,
-  page = "default", ...)
-
 \S4method{add_page}{i2dashboard}(dashboard, page, title,
   layout = "default", menu = NULL, sidebar = NULL, ...)
 
@@ -33,9 +29,7 @@
 
 \item{...}{Additional arguments passed on to \code{rmarkdown::render}.}
 
-\item{component}{The name of the component.}
-
-\item{page}{The name of the page to add the component to.}
+\item{page}{The name of the page to be added.}
 
 \item{title}{The title of the page to be added.}
 
@@ -45,12 +39,6 @@
 
 \item{dashboard}{A \linkS4class{i2dash::i2dashboard}.}
 
-\item{...}{Additional parameters passed to the components render function.}
-
-\item{dashboard}{A \linkS4class{i2dash::i2dashboard}.}
-
-\item{page}{The name of the page to be added.}
-
 \item{dashboard}{A \linkS4class{i2dash::i2dashboard}.}
 
 \item{page}{The name of the page to be removed.}
@@ -58,8 +46,6 @@
 \description{
 Method to assemble a dashboard to a Rmd file.
 
-Method to add a component to a page of an i2dashboard
-
 Method to add a page to an i2dashboard
 
 Method to remove a page to an i2dashboard

man/render_image.Rd

+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/components.R
+\name{render_image}
+\alias{render_image}
+\title{Method to embed an image file in a component}
+\usage{
+render_image(image, image_alt_text = NULL, title = NULL)
+}
+\arguments{
+\item{image}{The path to the image file.}
+
+\item{image_alt_text}{The alt text of the image.}
+
+\item{title}{The components title.}
+}
+\value{
+A character string containing the evaluated component
+}
+\description{
+Method to embed an image file in a component
+}

man/render_text.Rd

+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/components.R
+\name{render_text}
+\alias{render_text}
+\title{Method to embed content from a text file in a component}
+\usage{
+render_text(file, title = NULL)
+}
+\arguments{
+\item{file}{The file containing the text content.}
+
+\item{title}{The components title.}
+}
+\value{
+A character string containing the evaluated component
+}
+\description{
+Method to embed content from a text file in a component
+}