bridge.js

/*global phantom*/
/*eslint-disable strict*/
var webpage     = require('webpage');
var webserver   = require('webserver').create();
var system      = require('system');

var pages  = {};
var page_id = 1;

var callback_stack = [];

// Max interval without requests from master process
var WATCHDOG_TIMEOUT = 30000;

phantom.onError = function (msg, trace) {
  var msgStack = [ 'PHANTOM ERROR: ' + msg ];

  if (trace && trace.length) {
    msgStack.push('TRACE:');
    trace.forEach(function (t) {
      msgStack.push(' -> ' + (t.file || t.sourceURL) + ': ' + t.line + (t.function ? ' (in function ' + t.function + ')' : ''));
    });
  }

  system.stderr.writeLine(msgStack.join('\n'));
  phantom.exit(1);
};

var watchdog_timer_id = null;

// Kill phantom if parent disconnected
function watchdog_clear() {
  clearTimeout(watchdog_timer_id);

  watchdog_timer_id = setTimeout(function () {
    phantom.exit(0);
  }, WATCHDOG_TIMEOUT);
}

function lookup(obj, key, value) {
  // key can be either string or an array of strings
  if (!(typeof obj === 'object')) return null;

  if (typeof key === 'string') key = key.split('.');

  if (!Array.isArray(key)) return null;

  if (arguments.length > 2) {
    if (key.length === 1) obj[key[0]] = value;
    else obj[key[0]] = lookup(typeof obj[key[0]] === 'object' ? obj[key[0]] : {}, key.slice(1), value);

    return obj;
  }

  if (key.length === 1) return obj[key[0]];

  return lookup(obj[key[0]], key.slice(1));
}

function page_open(res, page, args) {
  page.open.apply(page, args.concat(function (success) {
    res.statusCode = 200;
    res.setHeader('Content-Type', 'application/json');
    res.write(JSON.stringify({ data: success }));
    res.close();
  }));
}

function include_js(res, page, args) {
  res.statusCode = 200;
  res.setHeader('Content-Type', 'application/json');
  res.write(JSON.stringify({ data: 'success' }));

  page.includeJs.apply(page, args.concat(function () {
    try {
      res.write('');
      res.close();
    } catch (e) {
      if (!/cannot call function of deleted QObject/.test(e)) { // Ignore this error
        page.onError(e);
      }
    }
  }));
}

webserver.listen('127.0.0.1:0', function (req, res) {
  // Update watchdog timer on every request
  watchdog_clear();

  if (req.method === 'GET') {
    res.statusCode = 200;
    res.setHeader('Content-Type', 'application/json');
    res.write(JSON.stringify({ data: callback_stack }));
    callback_stack = [];
    res.close();
  } else if (req.method === 'POST') {
    var request, error, output;

    try {
      request = JSON.parse(req.post);
    } catch (err) {
      error = err;
    }

    if (!error) {
      if (request.page) {
        if (request.method === 'open') { // special case this as it's the only one with a callback
          page_open(res, pages[request.page], request.args);
          return;
        } else if (request.method === 'includeJs') {
          include_js(res, pages[request.page], request.args);
          return;
        }
        try {
          output = pages[request.page][request.method].apply(pages[request.page], request.args);
        } catch (err) {
          error = err;
        }
      } else {
        try {
          output = global_methods[request.method].apply(global_methods, request.args);
        } catch (err) {
          error = err;
        }
      }
    }

    res.setHeader('Content-Type', 'application/json');
    if (error) {
      res.statusCode = 500;
      res.write(JSON.stringify(error));
    } else {
      res.statusCode = 200;
      res.write(JSON.stringify({ data: output }));
    }
    res.close();
  } else {
    throw 'Unknown request type!';
  }
});

var callbacks = [
  'onAlert', 'onCallback', 'onClosing', 'onConfirm', 'onConsoleMessage', 'onError', 'onFilePicker',
  'onInitialized', 'onLoadFinished', 'onLoadStarted', 'onNavigationRequested',
  'onPrompt', 'onResourceRequested', 'onResourceReceived', 'onResourceTimeout', 'onResourceError', 'onUrlChanged',
  // SlimerJS only
  'onAuthPrompt'
];

function setup_callbacks(id, page) {
  callbacks.forEach(function (cb) {
    page[cb] = function (parm) {
      var args = Array.prototype.slice.call(arguments);

      if ((cb === 'onResourceRequested') && (parm.url.indexOf('data:image') === 0)) {
        return;
      }

      if (cb === 'onClosing') { args = []; }
      callback_stack.push({ page_id: id, callback: cb, args: args });
    };
  });
  // Special case this
  page.onPageCreated = function (page) {
    var new_id = setup_page(page);
    callback_stack.push({ page_id: id, callback: 'onPageCreated', args: [ new_id ] });
  };
}

function setup_page(page) {
  var id    = page_id++;
  page.getProperty = function (prop) {
    return lookup(page, prop);
  };
  page.setProperty = function (prop, val) {
    // Special case for `paperSize.header.contents` property.
    if (prop === 'paperSize.header.contents' && val) {
      val = phantom.callback(eval('(' + val + ')'));
    } else if (prop === 'paperSize.header' && val.contents) {
      val.contents = phantom.callback(eval('(' + val.contents + ')'));
    } else if (prop === 'paperSize' && val.header && val.header.contents) {
      val.header.contents = phantom.callback(eval('(' + val.header.contents + ')'));
    }

    // Special case for `paperSize.footer.contents` property.
    if (prop === 'paperSize.footer.contents' && val) {
      val = phantom.callback(eval('(' + val + ')'));
    } else if (prop === 'paperSize.footer' && val.contents) {
      val.contents = phantom.callback(eval('(' + val.contents + ')'));
    } else if (prop === 'paperSize' && val.footer && val.footer.contents) {
      val.footer.contents = phantom.callback(eval('(' + val.footer.contents + ')'));
    }

    lookup(page, prop, val);
    return true;
  };
  page.setFunction = function (name, fn) {
    page[name] = eval('(' + fn + ')');
    return true;
  };
  pages[id] = page;
  setup_callbacks(id, page);
  return id;
}

var global_methods = {
  setProxy: function (ip, port, proxyType, user, password) {
    return phantom.setProxy(ip, port, proxyType, user, password);
  },
  createPage: function () {
    var page  = webpage.create();
    var id = setup_page(page);
    return { page_id: id };
  },

  injectJs: function (filename) {
    return phantom.injectJs(filename);
  },

  exit: function (code) {
    return phantom.exit(code);
  },

  addCookie: function (cookie) {
    return phantom.addCookie(cookie);
  },

  clearCookies: function () {
    return phantom.clearCookies();
  },

  deleteCookie: function (name) {
    return phantom.deleteCookie(name);
  },

  getProperty: function (prop) {
    return lookup(phantom, prop);
  },

  setProperty: function (prop, value) {
    lookup(phantom, prop, value);
    return true;
  }
};

// Start watchdog timer
watchdog_clear();

/*eslint-disable no-console*/
console.log('Ready [' + system.pid + '] [' + webserver.port + ']');