fh-fhc/lib/utils/prompt.js

A Command Line Interface for FeedHenry

/* globals i18n */

module.exports = prompt;

var buffer = "";
var tty = require("tty");

process.stdin.setRawMode = process.stdin.setRawMode || tty.setRawMode;

function prompt(p, def, silent, cb) {
  if (!cb) {
    cb = silent; silent = false;
  }
  if (!cb) {
    cb = def; def = undefined;
  }
  if (def) {
    p += "("+(silent ? "<hidden>" : def)+") ";
  }
  var r = (silent ? silentRead : read).bind(null, def, cb);
  if (!process.stdout.write(p)) {
    process.stdout.on("drain", function D() {
      process.stdout.removeListener("drain", D);
      r();
    });
  } else {
    r();
  }
}

function read(def, cb) {
  var stdin = process.openStdin(), val = "";
  stdin.resume();
  stdin.setEncoding("utf8");
  stdin.on("error", cb);
  stdin.on("data", function D(chunk) {
    val += buffer + chunk;
    buffer = "";
    val = val.replace(/\r/g, '');
    if (val.indexOf("\n") !== -1) {
      if (val !== "\n") {
        val = val.replace(/^\n+/, "");
      }
      buffer = val.substr(val.indexOf("\n"));
      val = val.substr(0, val.indexOf("\n"));
      stdin.pause();
      stdin.removeListener("data", D);
      stdin.removeListener("error", cb);
      val = val.trim() || def;
      cb(null, val);
    }
  });
}

function silentRead(def, cb) {
  var stdin = process.openStdin();
  var val = "";
  process.stdin.setRawMode(true);
  stdin.resume();
  stdin.on("error", cb);
  stdin.on("data", function D(c) {
    c = "" + c;
    switch (c) {
    case "\n": case "\r": case "\r\n": case "\u0004":
      process.stdin.setRawMode(false);
      stdin.removeListener("data", D);
      stdin.removeListener("error", cb);
      val = val.trim() || def;
      process.stdout.write("\n");
      stdin.pause();
      return cb(null, val);
    case "\u0003": case "\0":
      return cb(i18n._("cancelled"));
    default:
      val += buffer + c;
      buffer = "";
      break;
    }
  });
}