appium/sample-code/examples/node/helpers/promise-utils.js

"use strict";

var Q = require('q'),
    _ = require('underscore');

exports.each = function (fn) {
  return function (els) {
    var seq = _(els).map(function (el, i) {
      return function () {
        return fn(el, i);
      };
    });
    // iterating
    return seq.reduce(Q.when, new Q()).then(function () {
      return els;
    });
  };
};

exports.filter = function (fn) {
  return function (els) {
    var seq = _(els).map(function (el, i) {
      return function (filteredEls) {
        return fn(el, i).then(function (isOk) {
          if (isOk) filteredEls.push(el);
          return filteredEls;
        });
      };
    });
    // iterating
    return seq.reduce(Q.when, new Q([]));
  };
};

exports.printNames = exports.each(function (el, i) {
  return el.getAttribute('name').print(i + "--> ");
});

exports.filterDisplayed = exports.filter(function (el) {
  return el.isDisplayed();
});

exports.filterWithName = function (name) {
  return exports.filter(function (el) {
    return el.getAttribute('name').then(function (_name) {
      return _name === name;
    });
  });
};