alert弹框插件

(function (window, document) {
  'use strict';

  var win = window;
  var doc = document;
  var utils;
  function Utils() {
    this.overlayClass = 'bean-panel';
    this.box = null;
    this.textTemplate = {
      text: 'It is OK!',
      confirmButtonText: '确定',
      confirmButtonColor: '#FF5D3D',
      cancelButtonText: '取消',
      cancelButtonColor: '#CECECE',
      showCancelButton: false
    };
  }
  Utils.prototype = {
    // 初始化DOM节点
    init: function () {
      var temp = '' +
     '
 ' +
     '
 
  ' +
     '
  
' + this.textTemplate.text + '
 ' +
     '
  
    ' + '
   ' + this.textTemplate.cancelButtonText + '' + '
   ' + this.textTemplate.confirmButtonText + '' + '
  ' +
     '
 ';
      return temp;
    },
    getChild: function (opt) {
      var box = document.createElement('div');
      var _this = this;
      box.className = this.overlayClass;
      this.textTemplate.text = opt.text || this.textTemplate.text;
      this.textTemplate.confirmButtonText = opt.confirmButtonText ||
      this.textTemplate.confirmButtonText;
      this.textTemplate.cancelButtonText = opt.cancelButtonText ||
      this.textTemplate.cancelButtonText;
      this.textTemplate.cancelButtonColor = opt.cancelButtonColor ||
      this.textTemplate.cancelButtonColor;
      box.innerHTML = this.init();
      this.box = box;
      document.body.appendChild(this.box);
    },
    alert: function (opt) {
      var btns = null;
      var _this = this;
      this.getChild(opt);
      btns = doc.getElementsByClassName('btn-footer-ok');
      if (opt.showCancelButton) {
        btns[0].style.display = 'inline-block';
        btns[0].style.marginRight = '.2rem';
        btns[0].onclick = function () {
          if (opt.onCancel) {
            opt.onCancel();
          }
          _this.removeBox();
        };
      } else {
        btns[0].style.display = 'none';
        btns[1].style.width = '4.8rem';
      }
      btns[1].onclick = function () {
        if (opt.onConfirm) {
          opt.onConfirm();
        }
        _this.removeBox();
      };
    },
    extend: function (a, b) {
      var az = a;
      Object.keys(b).forEach(function (key) {
        az[key] = b[key];
      });
      return az;
    },
    removeBox: function () {
      var box = document.getElementsByClassName(this.overlayClass);
      document.body.removeChild(box[box.length - 1]);
    }
  };
  utils = new Utils();
  function BeanAlert(obj, callback) {
    var pars = obj || utils.textTemplate;
    if (callback) {
      pars.onConfirm = callback;
    }
    if (this instanceof BeanAlert) {
      this.params = pars;
    } else {
      utils.alert(pars);
    }
  }
  BeanAlert.prototype.show = function () {
    utils.alert(this.params);
  };
  if (typeof exports === 'object') {
    module.exports = BeanAlert;
  } else {
    win.beanAlert = BeanAlert;
  }
}(window, document));