R/index.R

In kylebmetrum/mdcontent: Manage content in markdown files

# Copyright (C) 2017  Metrum Research Group, LLC
#
# This file is part of mdcontent
#
# mdcontent is free software: you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 2 of the License, or
# (at your option) any later version.
#
# mdcontent is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with mdcontent  If not, see <http://www.gnu.org/licenses/>.


default <- list(title="",file="",
                tags="",maintainer="",ext="")


parse_index <- function(file,where,link) {
  stopifnot(file.exists(file))
  index <- yaml.load_file(file)
  out <- vector(mode="list",length=length(index))
  for(i in seq_along(index)) {
    x <- index[[i]]

    file <- paste0(names(index)[i])
    tags <- paste(x$tags,collapse=',')
    dd <- data_frame(title=x$title,
                     file=file,
                     tags=x$tags,
                     description=x$description,
                     maintainer=x$maintainer)
    out[[i]] <- dd

  }

  out <- bind_rows(out) %>% mutate(path = where)
  out <- mutate(out,File = file.path(link,file))
  out
}


taglink <- function(tag) {
  hash <- paste0("#tag--",tolower(gsub("[[:punct:]]", "-",tag)))
  paste0("[",tag,"](",hash,")")

}
initfile <- function(file,what) {
  if(file.exists(file)) {
    file.remove(file)
  }
  cat(file=file, what)
  return(file)
}
catapp <- function(file,...) {
  cat(file=file,...,append=TRUE)
}
link <- function(a,b) paste0("[",a,"](",b,")")
link2 <- function(a,b,sep=":",basename_only=TRUE) {
  bb <- b
  if(basename_only) bb <- basename(bb)
  paste0(a,sep," ",paste0("[",bb,"](",b,")"))
}
lvl1 <- function(...) {
  x <- paste(unlist(list(...)),collapse=" ")
  paste0("- ", x)
}
subheader <- function(...) {
  x <- paste(unlist(list(...)),collapse=" ")
  paste0("## ", x)
}
subsubheader <- function(...) paste0("#", subheader(...))

lvl2 <- function(...) {
  x <- paste(unlist(list(...)),collapse=" ")
  paste0("  - ", x)
}
mlvl2 <- function(...) {
  x <- unlist(list(...))
  x <- paste0("  - ",x)
  x <- paste(x,collapse="\n")
  x
}
details <- function(x) {
  paste0("<details>\n",x[1],"</details>")
}

write_file <- function(x,con) {
  tags <- unique(x$tags)
  File <- x$File[1]
  lnk <- link(x$title[1],x$File[1])
  tagsl <- taglink(tags)
  descr <- x$description

  catapp(file=con, lvl1(lnk),"\n")
  #catapp(file=con, lvl2("__title__: ", x$title[1]),"\n")
  catapp(file=con, lvl2("__file__: ", x$file[1]), "\n")
  #catapp(file=con,lvl2("__maintainer__: ", x$maintainer[1]),"\n")
  catapp(file=con,lvl2("__tags__: ", tagsl),"\n")
  catapp(file=con,lvl2(x$description[1]), "\n")

}

write_tag <- function(x,con) {
  .tag <- x$tags[1]
  catapp(con, subsubheader("tag: ", .tag), "\n")
  catapp(con, mlvl2(link2(x$title,x$File)),"\n")

}

##' Write an index.md file
##'
##' @param target target directory
##' @param index a yaml file containing index information
##' @param output output file name
##' @param link path prefix to link index document to indexed files
##'
##' @export
write_index <- function(target,index="index.yaml",output="index.md",link='.') {
  out <- parse_index(index,target,link)
  con <- initfile(output, "## Index by file\n")
  out <- dplyr::arrange(out,file)
  file_chunks <- split(out,out$File)
  foo <- lapply(file_chunks,write_file,con=con)
  catapp(con,"\n\n## Index by tag\n")
  out <- dplyr::arrange(out,tags)
  tag_chunks <- split(out,out$tags)
  foo <- lapply(tag_chunks,write_tag,con=con)
  return(out)
}