Rmarkdown caption tool

rmd_caption_helper.R

require(knitr)
render_caption = function(caption) {
  paste('<p class="caption">', caption, "</p>", sep="")
}
 
knit_hooks$set(html.cap = function(before, options, envir) {
    if(!before) {
      render_caption(options$html.cap)
    } else {
      # Do nothing (or set isTable flag to render_caption at the top?
    }
  }
)

require(R6)
Caption <-  R6Class("Caption",
  public = list(
    label_ = c(),
    text_ = c(),
    type_ = NA,
    initialize = function(type="Figure") {
      self$type_ <- type
    },
    label = function(l, t=NULL) {
        index = length(self$label_) + 1
        if (l %in% self$label_) {
            index <- which(self$label_ == l)
        } else {
            self$label_[index] <- l
        }
        if (!is.null(t)) {
            self$text_[index] <- t
        }
        which(l == self$label_)
    },
    text = function(l, t=NULL) {
        if (!l %in% self$label_) stop("No such label")
        index = which(l == self$label_)
        if (!is.null(t)) {
            self$text_[index] <- t
        }
        paste(self$type_, " ", which(l == self$label_), ". ", self$text_[index], sep="")
    }
  )
)

Footnote <- R6Class("Footnote",
  public = list(
    label_ = c(),
    text_ = c(),
    
    label = function(l, t=NULL) {
      self$update(l, t)
      writeLines(paste('<a href="#', l, '">',
        '<span id="', l, '_back"><sup>',
        which(l == self$label_), '</sup></span></a>', sep=""))
    },
    
    update = function(l, t=NULL) {
        index = length(self$label_) + 1
        if (l %in% self$label_) {
            index = which(self$label_ == l)
        } else {
            self$label_[index] <- l
        }
        if (!is.null(t)) {
            self$text_[index] <- t
        }
    },
    
    render = function(head="Notes") {
        writeLines('<div class="footnotes">')
        writeLines(head)
        writeLines('<ol>')
        items = paste('<li id="', self$label_, '">', self$text_,
                      ' <a href="#', self$label_,'_back">&#8617;</a>', '</li>', sep="")
        writeLines(items)
        writeLines('</ol></div>')
    }
  )
)