blessed-contrib/lib/server-utils.js

Build dashboards (or any other application) using ascii/ansi art and javascript.

'use strict';
var url = require('url')
  , contrib = require('../index')
  , blessed = require('blessed');

function OutputBuffer(options) {
  this.isTTY = true;
  this.columns = options.cols;
  this.rows = options.rows;
  this.write = function(s) {
    s = s.replace('\x1b8', ''); //not clear from where in blessed this code comes from. It forces the terminal to clear and loose existing content.
    options.res.write(s);
  };

  this.on = function() {};
}

function InputBuffer() {
  this.isTTY = true;
  this.isRaw = true;

  this.emit = function() {};

  this.setRawMode = function() {};
  this.resume = function() {};
  this.pause = function() {};

  this.on = function() {};
}

function serverError(req, res, err) {
  setTimeout(function() {
    if (!res.headersSent) res.writeHead(500, {'Content-Type': 'text/plain'});
    res.write('\r\n\r\n'+err+'\r\n\r\n');
    //restore cursor
    res.end('\u001b[?25h');
  }, 0);

  return true;
}


function createScreen(req, res) {
  var query = url.parse(req.url, true).query;

  var cols = query.cols || 250;
  var rows = query.rows || 50;

  if (cols<=35 || cols>=500 || rows<=5 || rows>=300) {
    serverError(req, res, 'cols must be bigger than 35 and rows must be bigger than 5');
    return null;
  }

  res.writeHead(200, {'Content-Type': 'text/plain'});

  var output = new contrib.OutputBuffer({res: res, cols: cols, rows: rows});
  var input = new contrib.InputBuffer(); //required to run under forever since it replaces stdin to non-tty
  var program = blessed.program({output: output, input: input});

  if (query.terminal) program.terminal = query.terminal;
  if (query.isOSX) program.isOSXTerm = query.isOSX;
  if (query.isiTerm2) program.isiTerm2 = query.isiTerm2;

  var screen = blessed.screen({program: program});
  return screen;
}


exports.createScreen = createScreen;
exports.OutputBuffer = OutputBuffer;
exports.InputBuffer = InputBuffer;
exports.serverError = serverError;