让你事半功倍的JS utils工具函数2

export function hasClass(el, className) {
  let reg = new RegExp('(^|\\s)' + className + '(\\s|$)');
  return reg.test(el.className);
}

export function addClass(el, className) {
  if (hasClass(el, className)) {
    return;
  }
  let curClass = el.className.split(' ');
  curClass.push(className);
  el.className = curClass.join(' ');
}

export function removeClass(el, className) {
  if (!hasClass(el, className)) {
    return;
  }
  let reg = new RegExp('(^|\\s)' + className + '(\\s|$)', 'g');
  el.className = el.className.replace(reg, ' ');
}

export function getScrollTop() {
  let e = 0
  return (
    document.documentElement && document.documentElement.scrollTop
      ? (e = document.documentElement.scrollTop)
      : document.body && (e = document.body.scrollTop),
    e
  )
}

export function distanceScroll(distance, callback) {
  const scrollTop = document.body.scrollTop || document.documentElement.scrollTop
  const docHeight = document.body.clientHeight
  const screenHeight = window.screen.availHeight
  const differ = scrollTop > docHeight - screenHeight - distance
  if (differ) {
    callback && callback()
  }
}

export const callPhone = (phone) => {
  const aElement = document.createElement('a')
  aElement.setAttribute('href', `tel:${phone}`)
  document.body.appendChild(aElement)
  aElement.click()
  document.body.removeChild(aElement)
}

export function copy(value, callback) {
  if (!document.queryCommandSupported('copy')) {
    callback('暂不支持复制')
    return
  }
  const textarea = document.createElement('textarea')
  textarea.value = value
  textarea.readOnly = Boolean('readOnly')
  document.body.appendChild(textarea)
  textarea.select()
  textarea.setSelectionRange(0, value.length)
  document.execCommand('copy')
  textarea.remove()
  callback('复制成功')
}

export function asyncLoadScript(url) {
  return new Promise(function (resolve, reject) {
    const tag = document.getElementsByTagName('script')
    for (const i of tag) {
      if (i.src === url) {
        resolve()
        return
      }
    }
    const script = document.createElement('script')
    script.type = 'text/javascript'
    script.src = url
    script.onerror = reject
    document.body.appendChild(script)
    script.onload = () => {
      resolve()
    }
  })
}

export function requestAnimationFrame() {
  return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || function (callback) {
    return setTimeout(callback, (callback.interval || （100 / 60) / 2);
  };
}()

const postExport = (url, data = {}) => {
  const form = document.createElement("form");
  form.style.display = "none";
  form.action = `${Config.baseURL}${url}`;
  form.method = "post";
  document.body.appendChild(form);
  // 动态创建input并给value赋值
  for (const key in data) {
    const input = document.createElement("input");
    input.type = "hidden";
    input.name = key;
    input.value = data[key];
    form.appendChild(input);
  }
  form.submit();
  form.remove();
}

export function dataURItoBuffer(dataURI) {
  var byteString = atob(dataURI.split(',')[1]);
  var buffer = new ArrayBuffer(byteString.length);
  var view = new Uint8Array(buffer);
  for (var i = 0; i < byteString.length; i++) {
    view[i] = byteString.charCodeAt(i);
  }
  return buffer;
}

export function dataURItoBlob(dataURI) {
  var mimeString = dataURI.split(',')[0].split(':')[1].split(';')[0];
  var buffer = dataURItoBuffer(dataURI);
  return new Blob([buffer], {
    type: mimeString
  });
}

export function orientationHelper(canvas, ctx, orientation) {
  var w = canvas.width;
  var h = canvas.height;
  if (orientation > 4) {
    canvas.width = h;
    canvas.height = w;
  }
  switch (orientation) {
    case 2:
      ctx.translate(w, 0);
      ctx.scale(-1, 1);
      break;
    case 3:
      ctx.translate(w, h);
      ctx.rotate(Math.PI);
      break;
    case 4:
      ctx.translate(0, h);
      ctx.scale(1, -1);
      break;
    case 5:
      ctx.rotate(0.5 * Math.PI);
      ctx.scale(1, -1);
      break;
    case 6:
      ctx.rotate(0.5 * Math.PI);
      ctx.translate(0, -h);
      break;
    case 7:
      ctx.rotate(0.5 * Math.PI);
      ctx.translate(w, -h);
      ctx.scale(-1, 1);
      break;
    case 8:
      ctx.rotate(-0.5 * Math.PI);
      ctx.translate(-w, 0);
      break;
  }
}