一个项目中的common.js文件,仅以做收藏

(function () {
  var oldAjax = jQuery.ajax;
  var EMPTY = {};
  var defaultOpts = {
    contentType: 'application/json',
    dataType: 'json',
    processData: false,
    beforeSend: function (jqXHR, options) {
      if (options.contentType === 'application/json' && typeof options.data !== 'string') {
        options.data = JSON.stringify(options.data);
      }
    }
  };
  jQuery.ajax = function (url, options) {
    options = options || EMPTY;

    if (typeof url === 'object') options = url;
    else if (typeof url === 'string') options.url = url;
    if (!options.url) throw new Error('bad args.');
    return new Promise(function (resolve, reject) {
      //这里的链式调用使用的是原生promise?

      oldAjax(Object.assign({}, defaultOpts, options)).then(function (obj) {
        if (obj.statusCode === 0) {
          // 如果接口返回成功直接 resolve 成功数据
          return resolve(obj.data);
        }

        // 将 messages 默认 join 成 message，方便业务层直接使用。
        obj.message = obj.messages.join('\n');
        reject(obj);
      }).catch(function (xhr) {
        var obj = xhr.responseJSON;
        if (!obj) {
          obj = {
            statusCode: xhr.statusCode,
            messages: [xhr.statusText]
          };
        }
        obj.message = obj.messages.join('\n');
        reject(obj);
      });
    });
  };


  /**
   * 获取表单验证码,
   * 传入设置src的图片的jquery对象,
   * 传入需要再window上用于存储图片验证码的uuid的属性名
   * @param elm  jquery对象
   * @param string  window[属性名]
   */
  window.getValid = function (elm, string) {
    var count = 0;
    _getValid(count);

    function _getValid() {
      if (count >= 10) {
        anertTip({content: '获取验证码失败, 请检查您的网络, 或联系管理员'});
      }
      $.get('/verification_code').then(function (data) {
        elm.attr('src', data.url);
        window[string] = data.id;
      }).catch(function () {
        _getValid(++count);
      });
    }
  };


  /**
   *  传入元素选择器, 获取改元素的value, 用于获取元素最原始的值,(没有想getValuse哪样会判断other input的逻辑)
   * @param seletor
   * @returns {*}
   */
  window.getBaseValue = function getBaseValue(seletor) {
    var type = $(seletor).attr('type') ? $(seletor).attr('type').toLowerCase() : $(seletor)[0].tagName.toLowerCase();
    if (type === 'radio') {
      return $(seletor + ':checked').val();
    } else if (type === 'text' || type === 'tel' || type === 'email' || type === 'hidden' || type === 'textarea') {
      return $(seletor).val();
    } else if (type === 'checkbox') {
      return window.getCheckboxValues(seletor);
    } else if (type === 'select') {
      return $(seletor + ' option:selected').val();
    }
  };

  /**
   * 用于得到多选框的值
   *
   * @param {*} string jquery选择器
   * @returns 返回多选框的值组成的数组
   */
  window.getCheckboxValues = function getCheckboxValues(string) {
    var CheckboxValues = [];
    $(string).each(function (index, item) {
      if (item.checked) {
        CheckboxValues.push($(item).val());
      }
    });
    return CheckboxValues;
  };

  /**
   * 传入数组,使用getValue方法,获取表单元素的值
   * @param secletors  [{name: 'name', selector: 'selector'},/...]
   * @returns {name: value, name1: value1,...}
   */
  window.getValues = function getValues(selectors) {
    var map = {};
    selectors.forEach(function (item) {
      map[item.name] = window.getValue(item.selector);
    });
    return map;
  };

  /**
   * 用于获取一个问题的值, 传入一个选择其, 判断是否有data-ohter这个自定义属性;
   * 如果有, 获取data-other的值,并凭借判断当前值是否等于data-other的值, 如果等于就判断为,需要获取other input的值.
   */
  window.getValue = function getValue(selector) {
    var value, otherData;
    value = window.getBaseValue(selector);
    otherData = $(selector).data('other');
    if (otherData && value == otherData) {//如果元素没有data-other的值, 或在值为空(单选情况)
      value = window.getBaseValue(selector.slice(0, -1) + 'Value]');
    } else if (otherData && $.isArray(value) && $.inArray(otherData, value) !== -1) {//如果存在, 或otherData被包含在了getValue中(多选情况)
      for (var i = 0; i < value.length; i++) {
        if (value[i] === otherData) {
          value[i] = window.getBaseValue(selector.slice(0, -1) + 'Value]');
          break;
        }
      }
    }
    return value;
  };

  /**
   * 下载文件
   * @param url
   */
  window.downloadFile = function downloadFile(url) {

    //以a标签加download实现, 兼容性不确定
    /*  var a = $('<a download="">');
      a.attr('href', url);
      $('body').append(a);
      a[0].click();
      a.remove();
  */
    //使用新开窗口实现, 只能下载不可被浏览器解析的文件
    window.open(url, '_blank');

    //使用iframe
    // var iframe = $('<iframe>');
    // $('body').append(iframe);
    // iframe[0].src = url;
  };

  /**
   * 点击下一步的时候， 提示waringNext
   *
   * @param {*} seletor
   */
  window.waringNext = function waringNext(seletor) {

    var type = $(seletor).attr('type') ? $(seletor).attr('type').toLowerCase() : $(seletor)[0].tagName.toLowerCase();

    if (type === 'radio') {
      // 判断是否需要提示other input是否为空
      var baseValue = window.getBaseValue(seletor),
        otherData = $(seletor).data('other');
      if (otherData && baseValue == otherData) {
        var otherValue = window.getValue(seletor.slice(0, -1) + 'Value]'),
          otherElm = $(seletor.slice(0, -1) + 'Value]');
        if (otherValue) {
          otherElm.css('border', '1px solid #d7dbe0');
        } else {
          otherElm.css('border', '1px solid #ff0000');
          otherElm[0].focus();
        }
      }
      // 通用的判断空
      if (!window.getValue(seletor)) {
        $('.' + ($(seletor).attr('name') + 'Tip')).show();
        $('.' + ($(seletor).attr('name') + 'Tip'))[0].scrollIntoView();
        return false;
      } else {
        $('.' + ($(seletor).attr('name') + 'Tip')).hide();
        return true;
      }
    } else if (type === 'text' || type === 'tel' || type === 'email') {
      if ($(seletor).data('type') === 'first') {
        var reg = new RegExp($(seletor).data('valid').slice(1, -1));
        if (!reg.test($(seletor).val())) {
          $('.' + ($(seletor).attr('name') + 'Tip')).show();
          return false;
        } else {
          $('.' + ($(seletor).attr('name') + 'Tip')).hide();
          return true;
        }
      } else if ($(seletor).data('type') === 'second' || $(seletor).data('type') === 'three') {
        if ($(seletor).val() === '') {
          $('.' + ($(seletor).attr('name') + 'Tip')).show();
          $('.' + ($(seletor).attr('name') + 'Tip'))[0].scrollIntoView();
          return false;
        } else {
          $('.' + ($(seletor).attr('name') + 'Tip')).hide();
          return true;
        }
      }
    } else if (type === 'checkbox') {
      var checkboxValue = window.getCheckboxValues(seletor);
      if ($.inArray('其他', checkboxValue) != -1 && !window.getValue(seletor.slice(0, -1) + 'Value]')) {
        //需要判断值other input是否为空
        $(seletor.slice(0, -1) + 'Value]').css('border', '1px solid #ff0000');
        $(seletor.slice(0, -1) + 'Value]')[0].focus();
        $('.' + ($(seletor).attr('name') + 'Tip')).show();
        $('.' + ($(seletor).attr('name') + 'Tip'))[0].scrollIntoView();
        return false;
      } else {
        $('.' + ($(seletor).attr('name') + 'Tip')).hide();
        $(seletor.slice(0, -1) + 'Value]').css('border', '1px solid #d7dbe0');
      }
      if (window.getCheckboxValues(seletor).length === 0) {
        $('.' + ($(seletor).attr('name') + 'Tip')).show();
        $('.' + ($(seletor).attr('name') + 'Tip'))[0].scrollIntoView();
        return false;
      } else {
        $('.' + ($(seletor).attr('name') + 'Tip')).hide();
        return true;
      }
    } else if (type === 'select') {

      if ($(seletor + ' option:selected').val() === '请选择') {
        $('.' + ($(seletor).attr('name') + 'Tip')).show();
        $('.' + ($(seletor).attr('name') + 'Tip'))[0].scrollIntoView();
        return false;
      } else {
        $('.' + ($(seletor).attr('name') + 'Tip')).hide();
        return true;
      }
    }
  };

  /**
   *
   * @returns {boolean}
   */
  window.is_weixin = function is_weixin() {
    var ua = navigator.userAgent.toLowerCase();
    if (ua.indexOf('micromessenger') != -1 && ua.indexOf('android') != -1) {
      return true;
    } else {
      return false;
    }
  };

  /**
   * 限制输入的函数
   */
  window.limitTextLength = function limitTextLength(targetParent, length) {
    $(targetParent + '> .input').on('input', function () {
      var value = $(this).val();
      if (value.length > length) {
        $(this).val(value.substring(0, length));
      } else {
        $(targetParent + '> span').text((length - value.length) + '/' + length);
      }
    });
  };
  /**
   * 禁止使用回车
   * @param event
   */
  window.nowrap = function noWrap(event) {
    if (event.keyCode==13) event.returnValue = false;
  };
})();

/**
 * 文本框根据输入内容自适应高度
 * @param                {HTMLElement}        输入框元素
 * @param                {Number}                设置光标与输入框保持的距离(默认0)
 * @param                {Number}                设置最大高度(可选)
 */
window.autoTextarea = function (elem, extra, maxHeight) {
  extra = extra || 0;
  var isFirefox = !!document.getBoxObjectFor || 'mozInnerScreenX' in window,
    isOpera = !!window.opera && !!window.opera.toString().indexOf('Opera'),
    addEvent = function (type, callback) {
      elem.addEventListener ?
        elem.addEventListener(type, callback, false) :
        elem.attachEvent('on' + type, callback);
    },
    getStyle = elem.currentStyle ? function (name) {
      var val = elem.currentStyle[name];
      if (name === 'height' && val.search(/px/i) !== 1) {
        var rect = elem.getBoundingClientRect();
        return rect.bottom - rect.top -
          parseFloat(getStyle('paddingTop')) -
          parseFloat(getStyle('paddingBottom')) + 'px';
      }
      return val;
    } : function (name) {
      return getComputedStyle(elem, null)[name];
    },
    minHeight = parseFloat(getStyle('height'));
  elem.style.resize = 'none';
  var change = function () {
    var scrollTop, height,
      padding = 0,
      style = elem.style;
    if (elem._length === elem.value.length) return;
    elem._length = elem.value.length;
    if (!isFirefox && !isOpera) {
      padding = parseInt(getStyle('paddingTop')) + parseInt(getStyle('paddingBottom'));
    }
    scrollTop = document.body.scrollTop || document.documentElement.scrollTop;
    elem.style.height = minHeight + 'px';
    if (elem.scrollHeight > minHeight) {
      if (maxHeight && elem.scrollHeight > maxHeight) {
        height = maxHeight - padding;
        style.overflowY = 'auto';
      } else {
        height = elem.scrollHeight - padding;
        style.overflowY = 'hidden';
      }
      style.height = height + extra + 'px';
      scrollTop += parseInt(style.height) - elem.currHeight;
      document.body.scrollTop = scrollTop;
      document.documentElement.scrollTop = scrollTop;
      elem.currHeight = parseInt(style.height);
    }
  };
  addEvent('propertychange', change);
  addEvent('input', change);
  addEvent('focus', change);
  change();
};