常用工具方法整理

本文主要整理收录在项目开发中，遇到的工具方法

生成唯一的ID

export function genUid(){
  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
              var r = Math.random()*16|0, v = c == 'x' ? r : (r&0x3|0x8);
              return v.toString(16);
          });
}

获取Url上的参数，以{}返回

export function getQueryString() {
    let hash = location.hash;
    let queryObject = {};
    let markIndex = hash.indexOf("?");
    // contain query string in fragments
    if (markIndex > -1) {
      // build query object
      let queryString = hash.slice(markIndex + 1);
      let queryArray = queryString.split('&');
      for (let i = 0; i < queryArray.length; i++) {
        let queryPair = queryArray[i].split('=');
        if (queryPair[0] !== '_k') {
          queryObject[queryPair[0]] = decodeURIComponent(queryPair[1]);
        }
      }
    }
    return queryObject;
  }

获取指定cookie

function getCookie(name) {
  var arr, reg = new RegExp("(^| )" + name + "=([^;]*)(;|$)");
  if (arr = document.cookie.match(reg))
      return unescape(arr[2]);
      return null;
}

让插件兼容commonjs AMD CMD 和原生JS

    if (typeof module !== 'undefined' && typeof exports === 'object') {
        module.exports = beisenWebim;
    } else if (typeof define === 'function' && (define.amd || define.cmd)) {
        define(function () {
            return beisenWebim;
        });
    } else {
        this.beisenWebim = beisenWebim;
    }
}).call(function () {
    return this || (typeof window !== 'undefined' ? window : global);
});

异常捕获函数

let errorObject = { value: null }
function tryCatch(fn, ctx) {
  try {
    return fn.apply(ctx)
  } catch (e) {
    errorObject.value = e
    return errorObject
  }
}
//使用
var a=function(){
console.log(r)
}
let result = tryCatch(a,null)
if(result == errorObject) console.log(errorObject.value)
else{//do something else}

获取光标在textarea的位置坐标

// The properties that we copy into a mirrored div.
// Note that some browsers, such as Firefox,
// do not concatenate properties, i.e. padding-top, bottom etc. -> padding,
// so we have to do every single property specifically.
var properties = [
  'direction',  // RTL support
  'boxSizing',
  'width',  // on Chrome and IE, exclude the scrollbar, so the mirror div wraps exactly as the textarea does
  'height',
  'overflowX',
  'overflowY',  // copy the scrollbar for IE

  'borderTopWidth',
  'borderRightWidth',
  'borderBottomWidth',
  'borderLeftWidth',
  'borderStyle',

  'paddingTop',
  'paddingRight',
  'paddingBottom',
  'paddingLeft',

  // https://developer.mozilla.org/en-US/docs/Web/CSS/font
  'fontStyle',
  'fontVariant',
  'fontWeight',
  'fontStretch',
  'fontSize',
  'fontSizeAdjust',
  'lineHeight',
  'fontFamily',

  'textAlign',
  'textTransform',
  'textIndent',
  'textDecoration',  // might not make a difference, but better be safe

  'letterSpacing',
  'wordSpacing',

  'tabSize',
  'MozTabSize'

];

var isBrowser = (typeof window !== 'undefined');
var isFirefox = (isBrowser && window.mozInnerScreenX != null);

export default function getCaretCoordinates(element, position, options) {
  if(!isBrowser) {
    throw new Error('textarea-caret-position#getCaretCoordinates should only be called in a browser');
  }

  var debug = options && options.debug || false;
  if (debug) {
    var el = document.querySelector('#input-textarea-caret-position-mirror-div');
    if ( el ) { el.parentNode.removeChild(el); }
  }

  // mirrored div
  var div = document.createElement('div');
  div.id = 'input-textarea-caret-position-mirror-div';
  document.body.appendChild(div);

  var style = div.style;
  var computed = window.getComputedStyle? getComputedStyle(element) : element.currentStyle;  // currentStyle for IE < 9

  // default textarea styles
  style.whiteSpace = 'pre-wrap';
  if (element.nodeName !== 'INPUT')
    style.wordWrap = 'break-word';  // only for textarea-s

  // position off-screen
  style.position = 'absolute';  // required to return coordinates properly
  if (!debug)
    style.visibility = 'hidden';  // not 'display: none' because we want rendering

  // transfer the element's properties to the div
  properties.forEach(function (prop) {
    style[prop] = computed[prop];
  });

  if (isFirefox) {
    // Firefox lies about the overflow property for textareas: https://bugzilla.mozilla.org/show_bug.cgi?id=984275
    if (element.scrollHeight > parseInt(computed.height))
      style.overflowY = 'scroll';
  } else {
    style.overflow = 'hidden';  // for Chrome to not render a scrollbar; IE keeps overflowY = 'scroll'
  }

  div.textContent = element.value.substring(0, position);
  // the second special handling for input type="text" vs textarea: spaces need to be replaced with non-breaking spaces - http://stackoverflow.com/a/13402035/1269037
  if (element.nodeName === 'INPUT')
    div.textContent = div.textContent.replace(/\s/g, '\u00a0');

  var span = document.createElement('span');
  // Wrapping must be replicated *exactly*, including when a long word gets
  // onto the next line, with whitespace at the end of the line before (#7).
  // The  *only* reliable way to do that is to copy the *entire* rest of the
  // textarea's content into the <span> created at the caret position.
  // for inputs, just '.' would be enough, but why bother?
  span.textContent = element.value.substring(position) || '.';  // || because a completely empty faux span doesn't render at all
  div.appendChild(span);

  var coordinates = {
    top: span.offsetTop + parseInt(computed['borderTopWidth']),
    left: span.offsetLeft + parseInt(computed['borderLeftWidth'])
  };

  if (debug) {
    span.style.backgroundColor = '#aaa';
  } else {
    document.body.removeChild(div);
  }

  return coordinates;
}

//调用方式
let coordinates = getCaretCoordinates(e.target, e.target.selectionEnd);