R/print.R

In biblio: Interacting with BibTeX Databases

#' @name print
#' @rdname print
#'
#' @title Print content of lib_df objects
#'
#' @description
#' A method for a brief overview on the content of a [lib_df-class] or a
#' [comp_df-class] object.
#'
#' @param x An object of class 'lib_df'.
#' @param maxsum An integer value indicating the number of entries to be
#'     displayed in the printed output.
#' @param ... Further arguments passed among methods.
#'
#' @author Miguel Alvarez
#'
#' @example examples/print.R
#'
#' @return
#' A print in the console.
#'
#' @aliases print,lib_df-method
#' @method print lib_df
#'
#' @export
print.lib_df <- function(x, maxsum = 4, ...) {
  cat(paste0(
    "Object of class 'lib_df'\n\n",
    "Number of references: ", nrow(x), "\n",
    "Number of variables: ", ncol(x), "\n",
    "Duplicated entries: ", sum(duplicated(x$bibtexkey)), "\n\n"
  ))
  if (maxsum > nrow(x)) {
    print(as(x, "bibentry"))
  } else {
    print(as(x[1:maxsum, ], "bibentry"))
    cat("\n[TRUNCATED]\n")
  }
}

#' @rdname print
#' @aliases print,comp_df-method
#' @method print comp_df
#' @export
print.comp_df <- function(x, ...) {
  if (length(x$deleted_vars) > 0) {
    cat(paste0(
      "## deleted variables (", length(x$deleted_vars), "):\n'",
      paste0(x$deleted_vars, collapse = "' '"), "'\n\n"
    ))
  }
  if (length(x$added_vars) > 0) {
    cat(paste0(
      "## added variables (", length(x$added_vars), "):\n'",
      paste0(x$added_vars, collapse = "' '"), "'\n\n"
    ))
  }
  if (length(x$deleted) > 0) {
    cat(paste0(
      "## deleted entries (", length(x$deleted), "):\n'",
      paste0(x$deleted, collapse = "' '"), "'\n\n"
    ))
  }
  if (length(x$added) > 0) {
    cat(paste0(
      "## added entries (", length(x$added), "):\n'",
      paste0(x$added, collapse = "' '"), "'\n\n"
    ))
  }
  if (nrow(x$updated) > 0) {
    for (i in rownames(x$updated)) {
      cat(paste0("## updates in entry '", i, "'\n"))
      for (j in colnames(x$updated)[x$updated[i, ]]) {
        cat(paste0(
          " - old ", j, ": ", x$old_vals[i, j],
          "\n - new ", j,
          ": ", x$new_vals[i, j], "\n\n"
        ))
      }
    }
  }
  if ((length(x$deleted_vars) == 0) & (length(x$added_vars) == 0) &
    (length(x$deleted) == 0) & (length(x$added) == 0) &
    (nrow(x$updated) == 0)) {
    cat("## no changes detected\n\n")
  }
}