zcloud-ui/src/utils/download.js

A Component Library for Vue.js.

/* eslint-disable*/
function download (data, strFileName, strMimeType) {
  var self = window, // this script is only for browsers anyway...
    defaultMime = 'application/octet-stream', // this default mime also triggers iframe downloads
    mimeType = strMimeType || defaultMime,
    payload = data,
    url = !strFileName && !strMimeType && payload,
    anchor = document.createElement('a'),
    toString = function (a) { return String(a); },
    myBlob = (self.Blob || self.MozBlob || self.WebKitBlob || toString),
    fileName = strFileName || 'download',
    blob,
    reader;
  myBlob = myBlob.call ? myBlob.bind(self) : Blob;
  if (String(this) === 'true') { // reverse arguments, allowing download.bind(true, "text/xml", "export.xml") to act as a callback
    payload = [payload, mimeType];
    mimeType = payload[0];
    payload = payload[1];
  }

  if (url && url.length < 2048) { // if no filename and no mime, assume a url was passed as the only argument
    fileName = url.split('/').pop().split('?')[0];
    anchor.href = url; // assign href prop to temp anchor
		  	if (anchor.href.indexOf(url) !== -1) { // if the browser determines that it's a potentially valid url path:
        		var ajax = new XMLHttpRequest();
        		ajax.open('GET', url, true);
        		ajax.responseType = 'blob';
        		ajax.onload = function (e) { 
				  download(e.target.response, fileName, defaultMime);
      };
        		setTimeout(function () { ajax.send(); }, 0); // allows setting custom ajax headers using the return:
			    return ajax;
    } // end if valid url?
  } // end if url?

  // go ahead and download dataURLs right away
  if (/^data\:[\w+\-]+\/[\w+\-]+[,;]/.test(payload)) {
    if (payload.length > (1024 * 1024 * 1.999) && myBlob !== toString) {
      payload = dataUrlToBlob(payload);
      mimeType = payload.type || defaultMime;
    } else {			
      return navigator.msSaveBlob // IE10 can't do a[download], only Blobs:
        ? navigator.msSaveBlob(dataUrlToBlob(payload), fileName)
        : saver(payload); // everyone else can save dataURLs un-processed
    }
  }// end if dataURL passed?

  blob = payload instanceof myBlob
    ? payload
    : new myBlob([payload], { type: mimeType });

  function dataUrlToBlob (strUrl) {
    var parts = strUrl.split(/[:;,]/),
      type = parts[1],
      decoder = parts[2] == 'base64' ? atob : decodeURIComponent,
      binData = decoder(parts.pop()),
      mx = binData.length,
      i = 0,
      uiArr = new Uint8Array(mx);

    for (i; i < mx; ++i) uiArr[i] = binData.charCodeAt(i);

    return new myBlob([uiArr], { type: type });
		 }

  function saver (url, winMode) {
    if ('download' in anchor) { // html5 A[download]
      anchor.href = url;
      anchor.setAttribute('download', fileName);
      anchor.className = 'download-js-link';
      anchor.innerHTML = 'downloading...';
      anchor.style.display = 'none';
      document.body.appendChild(anchor);
      setTimeout(function () {
        anchor.click();
        document.body.removeChild(anchor);
        if (winMode === true) { setTimeout(function () { self.URL.revokeObjectURL(anchor.href); }, 250); }
      }, 66);
      return true;
    }

    // handle non-a[download] safari as best we can:
    if (/(Version)\/(\d+)\.(\d+)(?:\.(\d+))?.*Safari\//.test(navigator.userAgent)) {
      url = url.replace(/^data:([\w\/\-\+]+)/, defaultMime);
      if (!window.open(url)) { // popup blocked, offer direct download:
        if (confirm('Displaying New Document\n\nUse Save As... to download, then click back to return to this page.')) { location.href = url; }
      }
      return true;
    }

    // do iframe dataURL download (old ch+FF):
    var f = document.createElement('iframe');
    document.body.appendChild(f);

    if (!winMode) { // force a mime that will download:
      url = 'data:' + url.replace(/^data:([\w\/\-\+]+)/, defaultMime);
    }
    f.src = url;
    setTimeout(function () { document.body.removeChild(f); }, 333);
  }// end saver

  if (navigator.msSaveBlob) { // IE10+ : (has Blob, but not a[download] or URL)
    return navigator.msSaveBlob(blob, fileName);
  }

  if (self.URL) { // simple fast and modern way using Blob and URL:
    saver(self.URL.createObjectURL(blob), true);
  } else {
    // handle non-Blob()+non-URL browsers:
    if (typeof blob === 'string' || blob.constructor === toString) {
      try {
        return saver('data:' + mimeType + ';base64,' + self.btoa(blob));
      } catch (y) {
        return saver('data:' + mimeType + ',' + encodeURIComponent(blob));
      }
    }

    // Blob but not URL support:
    reader = new FileReader();
    reader.onload = function (e) {
      saver(this.result);
    };
    reader.readAsDataURL(blob);
  }
  return true;
} /* end download() */

export default download;