R/flashCard.R

In jienagu/flashCard: Create a Flash Card

#' Create a flash card
#'
#' Create a flash card  with desired data frame
#'
#' @param data df with front and back columns
#' @param frontColor frond side background color
#' @param backColor back side background color
#' @param front_text_color frond text color
#' @param back_text_color back text color
#' @param width width
#' @param height height
#' @param elementId element id
#'
#' @import htmlwidgets
#' @examples
#' df1 <- data.frame(
#' front = c("Title front","contentfront", "content second line"),
#' back = c("Title back","content back", "second line")
#' )
#' flashCard(df1, elementId = "card", front_text_color = "grey")
#'
#' @export
flashCard <- function(data, frontColor = '#090e87', backColor = '#3443c9',front_text_color = "white",
                      text_align = "center", back_text_color = "white", width = NULL, height = NULL, elementId = NULL) UseMethod("flashCard")

#' @export
#' @method flashCard data.frame
flashCard.data.frame <- function(data, frontColor = '#090e87', backColor = '#3443c9',front_text_color = "white",
                                 text_align = "center", back_text_color = "white", width = NULL, height = NULL, elementId = NULL) {

  # forward options using x
  x = list(
    data = data,
    frontColor = frontColor,
    backColor = backColor,
    front_text_color = front_text_color,
    back_text_color = back_text_color,
    text_align = text_align
  )

  attr(x, "TOJSON_ARGS") <- list(
    dataframe = "columns", null = "null", na = "null", auto_unbox = TRUE,
    use_signif = TRUE, force = TRUE,
    POSIXt = "ISO8601", UTC = TRUE, rownames = FALSE, keep_vec_names = TRUE,
    json_verbatim = TRUE
  )

  # create widget
  create_card(x, width, height, elementId)
}

#' @export
#' @method flashCard list
flashCard.list <- function(data, frontColor = '#090e87', backColor = '#3443c9',front_text_color = "white",
                      back_text_color = "white", width = NULL, height = NULL, elementId = NULL) {
  # accept list but force conversion to character
  # Converts shiny::h1() to <h1></h1>
  data[["front"]] <- lapply(data[["front"]], as.character)
  data[["back"]] <- lapply(data[["back"]], as.character)

  # forward options using x
  x = list(
    data = data,
    frontColor = frontColor,
    backColor = backColor,
    front_text_color = front_text_color,
    back_text_color = back_text_color
  )

  attr(x, "TOJSON_ARGS") <- list(
    dataframe = "columns", null = "null", na = "null", auto_unbox = TRUE,
    use_signif = TRUE, force = TRUE,
    POSIXt = "ISO8601", UTC = TRUE, rownames = FALSE, keep_vec_names = TRUE,
    json_verbatim = TRUE
  )

  # create widget
  create_card(x, width, height, elementId)
}

create_card <- function(x, width, height, elementId){
  htmlwidgets::createWidget(
    name = 'flashCard',
    x,
    width = width,
    height = height,
    package = 'flashCard',
    elementId = elementId,
    sizingPolicy = htmlwidgets::sizingPolicy(
      defaultWidth = "100%",
      defaultHeight = 135
    )
  )
}

#' Shiny bindings for flashCard
#'
#' Output and render functions for using flashCard within Shiny
#' applications and interactive Rmd documents.
#'
#' @param outputId output variable to read from
#' @param width width of the widget
#' @param height height of the widget
#' @param expr An expression that generates a flashCard
#' @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 flashCard-shiny
#'
#' @export
flashCardOutput <- function(outputId, width = "300px", height = "135px"){
  htmlwidgets::shinyWidgetOutput(outputId, 'flashCard', width, height, package = 'flashCard')
}

#' @rdname flashCard-shiny
#' @export
renderFlashCard <- function(expr, env = parent.frame(), quoted = FALSE) {
  if (!quoted) { expr <- substitute(expr) } # force quoted
  htmlwidgets::shinyRenderWidget(expr, flashCardOutput, env, quoted = TRUE)
}