一个允许在客户端保存文件的解决方案
This script should not be not be installed directly. It is a library for other scripts to include with the meta directive // @require https://update.greasyfork.org/scripts/450828/1090308/FileSaver-eligrey.js
function enableSaveAs() {
/*
* FileSaver.js
* A saveAs() FileSaver implementation.
*
* By Eli Grey, http://eligrey.com
*
* License : https://github.com/eligrey/FileSaver.js/blob/master/LICENSE.md (MIT)
* source : http://purl.eligrey.com/github/FileSaver.js
*/
// The one and only way of getting global scope in all environments
// https://stackoverflow.com/q/3277182/1008999
var _global = typeof window === 'object' && window.window === window
? window : typeof self === 'object' && self.self === self
? self : typeof global === 'object' && global.global === global
? global
: this
function bom(blob, opts) {
if (typeof opts === 'undefined') opts = { autoBom: false }
else if (typeof opts !== 'object') {
console.warn('Deprecated: Expected third argument to be a object')
opts = { autoBom: !opts }
}
// prepend BOM for UTF-8 XML and text/* types (including HTML)
// note: your browser will automatically convert UTF-16 U+FEFF to EF BB BF
if (opts.autoBom && /^\s*(?:text\/\S*|application\/xml|\S*\/\S*\+xml)\s*;.*charset\s*=\s*utf-8/i.test(blob.type)) {
return new Blob([String.fromCharCode(0xFEFF), blob], { type: blob.type })
}
return blob
}
function download(url, name, opts) {
var xhr = new XMLHttpRequest()
xhr.open('GET', url)
xhr.responseType = 'blob'
xhr.onload = function () {
saveAs(xhr.response, name, opts)
}
xhr.onerror = function () {
console.error('could not download file')
}
xhr.send()
}
function corsEnabled(url) {
var xhr = new XMLHttpRequest()
// use sync to avoid popup blocker
xhr.open('HEAD', url, false)
try {
xhr.send()
} catch (e) { }
return xhr.status >= 200 && xhr.status <= 299
}
// `a.click()` doesn't work for all browsers (#465)
function click(node) {
try {
node.dispatchEvent(new MouseEvent('click'))
} catch (e) {
var evt = document.createEvent('MouseEvents')
evt.initMouseEvent('click', true, true, window, 0, 0, 0, 80,
20, false, false, false, false, 0, null)
node.dispatchEvent(evt)
}
}
// Detect WebView inside a native macOS app by ruling out all browsers
// We just need to check for 'Safari' because all other browsers (besides Firefox) include that too
// https://www.whatismybrowser.com/guides/the-latest-user-agent/macos
var isMacOSWebView = _global.navigator && /Macintosh/.test(navigator.userAgent) && /AppleWebKit/.test(navigator.userAgent) && !/Safari/.test(navigator.userAgent)
var saveAs = _global.saveAs || (
// probably in some web worker
(typeof window !== 'object' || window !== _global)
? function saveAs() { /* noop */ }
// Use download attribute first if possible (#193 Lumia mobile) unless this is a macOS WebView
: ('download' in HTMLAnchorElement.prototype && !isMacOSWebView)
? function saveAs(blob, name, opts) {
var URL = _global.URL || _global.webkitURL
// Namespace is used to prevent conflict w/ Chrome Poper Blocker extension (Issue #561)
var a = document.createElementNS('http://www.w3.org/1999/xhtml', 'a')
name = name || blob.name || 'download'
a.download = name
a.rel = 'noopener' // tabnabbing
// TODO: detect chrome extensions & packaged apps
// a.target = '_blank'
if (typeof blob === 'string') {
// Support regular links
a.href = blob
if (a.origin !== location.origin) {
corsEnabled(a.href)
? download(blob, name, opts)
: click(a, a.target = '_blank')
} else {
click(a)
}
} else {
// Support blobs
a.href = URL.createObjectURL(blob)
setTimeout(function () { URL.revokeObjectURL(a.href) }, 4E4) // 40s
setTimeout(function () { click(a) }, 0)
}
}
// Use msSaveOrOpenBlob as a second approach
: 'msSaveOrOpenBlob' in navigator
? function saveAs(blob, name, opts) {
name = name || blob.name || 'download'
if (typeof blob === 'string') {
if (corsEnabled(blob)) {
download(blob, name, opts)
} else {
var a = document.createElement('a')
a.href = blob
a.target = '_blank'
setTimeout(function () { click(a) })
}
} else {
navigator.msSaveOrOpenBlob(bom(blob, opts), name)
}
}
// Fallback to using FileReader and a popup
: function saveAs(blob, name, opts, popup) {
// Open a popup immediately do go around popup blocker
// Mostly only available on user interaction and the fileReader is async so...
popup = popup || open('', '_blank')
if (popup) {
popup.document.title =
popup.document.body.innerText = 'downloading...'
}
if (typeof blob === 'string') return download(blob, name, opts)
var force = blob.type === 'application/octet-stream'
var isSafari = /constructor/i.test(_global.HTMLElement) || _global.safari
var isChromeIOS = /CriOS\/[\d]+/.test(navigator.userAgent)
if ((isChromeIOS || (force && isSafari) || isMacOSWebView) && typeof FileReader !== 'undefined') {
// Safari doesn't allow downloading of blob URLs
var reader = new FileReader()
reader.onloadend = function () {
var url = reader.result
url = isChromeIOS ? url : url.replace(/^data:[^;]*;/, 'data:attachment/file;')
if (popup) popup.location.href = url
else location = url
popup = null // reverse-tabnabbing #460
}
reader.readAsDataURL(blob)
} else {
var URL = _global.URL || _global.webkitURL
var url = URL.createObjectURL(blob)
if (popup) popup.location = url
else location.href = url
popup = null // reverse-tabnabbing #460
setTimeout(function () { URL.revokeObjectURL(url) }, 4E4) // 40s
}
}
)
_global.saveAs = saveAs.saveAs = saveAs
if (typeof module !== 'undefined') {
module.exports = saveAs;
}
}