本文介绍了js基于FileSaver.js 浏览器导出Excel文件，分享给大家，也给自己做个笔记
限制一：不同浏览器对 blob 对象有不同的限制
具体看看下面这个表格（出自FileSaver.js）：
这一点限制对小文件(几十kb)可能没什么影响，但对稍微大一点的文件影响就很大了。试想，用户要下载一个 100mb 的文件，如果他点击了下载按钮之后没看到下载提示的话，他肯定会继续按，等他按了几次之后还没看到下载提示时，他就会抱怨我们的网站，然后离开了。 然而事实上下载的的确确发生了，只是要等到下载完文件之后才能构建 blob 对象，再转化成文件。而且，用户再触发多几次下载就会造成一些资源上的浪费。 因此，如果是要下载大文件的话，还是推荐直接创建一个 标签拉~
写 html 也好，写 JavaScript 动态创建也好，用自己喜欢的方式去创建就好了。 FileSaver.js /global self / /! @source http://purl.eligrey.com/github/FileSaver.js/blob/master/FileSaver.js / var saveAs = saveAs || (function(view) { ; } FS_proto.abort = function(){}; FS_proto.error = return saveAs; if (typeof module !== "undefined" && module.exports) { 以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持编程之家。 原文地址：https://www.jb51.cc/js/37143.html 版权声明：本文内容由互联网用户自发贡献，该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容， 请发送邮件至 dio@foxmail.com 举报，一经查实，本站将立刻删除。Constructs as
Filenames
Max Blob Size
Dependencies
限制二：构建完 blob 对象后才会转换成文件
/jslint bitwise: true,indent: 4,laxbreak: true,laxcomma: true,smarttabs: true,plusplus: true /
"use strict";
// IE <10 is explicitly unsupported
if (typeof view === "undefined" || typeof navigator !== "undefined" && /MSIE [1-9]./.test(navigator.userAgent)) {
return;
}
var
doc = view.document
// only get URL when necessary in case Blob.js hasn't overridden it yet,get_URL = function() {
return view.URL || view.webkitURL || view;
},save_link = doc.createElementNS("http://www.w3.org/1999/xhtml","a"),can_use_save_link = "download" in save_link,click = function(node) {
var event = new MouseEvent("click");
node.dispatchEvent(event);
},is_safari = /constructor/i.test(view.HTMLElement) || view.safari,is_chrome_ios =/CriOS\/[\d]+/.test(navigator.userAgent),throw_outside = function(ex) {
(view.setImmediate || view.setTimeout)(function() {
throw ex;
},0);
},force_saveable_type = "application/octet-stream"
// the Blob API is fundamentally broken as there is no "downloadfinished" event to subscribe to,arbitrary_revoke_timeout = 1000 40 // in ms,revoke = function(file) {
var revoker = function() {
if (typeof file === "string") { // file is an object URL
get_URL().revokeObjectURL(file);
} else { // file is a File
file.remove();
}
};
setTimeout(revoker,arbitrary_revoke_timeout);
},dispatch = function(filesaver,event_types,event) {
event_types = [].concat(event_types);
var i = event_types.length;
while (i--) {
var listener = filesaver["on" + event_types[i]];
if (typeof listener === "function") {
try {
listener.call(filesaver,event || filesaver);
} catch (ex) {
throw_outside(ex);
}
}
}
},auto_bom = function(blob) {
// 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 (/^\s(?:text\/\S|application\/xml|\S\/\S+xml)\s;.charset\s=\sutf-8/i.test(blob.type)) {
return new Blob([String.fromCharCode(0xFEFF),blob],{type: blob.type});
}
return blob;
},FileSaver = function(blob,name,no_auto_bom) {
if (!no_auto_bom) {
blob = auto_bom(blob);
}
// First try a.download,then web filesystem,then object URLs
var
filesaver = this,type = blob.type,force = type === force_saveable_type,object_url,dispatch_all = function() {
dispatch(filesaver,"writestart progress write writeend".split(" "));
}
// on any filesys errors revert to saving with object URLs,fs_error = function() {
if ((is_chrome_ios || (force && is_safari)) && view.FileReader) {
// Safari doesn't allow downloading of blob urls
var reader = new FileReader();
reader.onloadend = function() {
var url = is_chrome_ios ? reader.result : reader.result.replace(/^data:[^;]*;/,'data:attachment/file;');
var popup = view.open(url,'_blank');
if(!popup) view.location.href = url;
url=undefined; // release reference before dispatching
filesaver.readyState = filesaver.DONE;
dispatch_all();
};
reader.readAsDataURL(blob);
filesaver.readyState = filesaver.INIT;
return;
}
// don't create more object URLs than needed
if (!object_url) {
object_url = get_URL().createObjectURL(blob);
}
if (force) {
view.location.href = object_url;
} else {
var opened = view.open(object_url,"_blank");
if (!opened) {
// Apple does not allow window.open,see https://developer.apple.com/library/safari/documentation/Tools/Conceptual/SafariExtensionGuide/WorkingwithWindowsandTabs/WorkingwithWindowsandTabs.html
view.location.href = object_url;
}
}
filesaver.readyState = filesaver.DONE;
dispatch_all();
revoke(object_url);
}
;
filesaver.readyState = filesaver.INIT; if (can_use_save_link) {
object_url = get_URL().<a href="https://www.jb51.cc/tag/createObjectURL/" target="_blank" class="keywords">createObjectURL</a>(blob);
setTimeout(function() {
save_link.href = object_url;
save_link.download = name;
click(save_link);
<a href="https://www.jb51.cc/tag/dis/" target="_blank" class="keywords">dis</a>patch_all();
revoke(object_url);
filesaver.readyState = filesaver.DONE;
});
return;
}
fs_error();
},FS_proto = FileSaver.prototype,saveAs = function(blob,no_auto_bom) {
return new FileSaver(blob,name || blob.name || "download",no_auto_bom);
}
// IE 10+ (native saveAs)
if (typeof navigator !== "undefined" && navigator.msSaveOrOpenBlob) {
return function(blob,no_auto_bom) {
name = name || blob.name || "download"; if (!no_auto_bom) {
blob = auto_bom(blob);
}
return navigator.msSaveOrOpenBlob(blob,name);
};
FS_proto.readyState = FS_proto.INIT = 0;
FS_proto.WRITING = 1;
FS_proto.DONE = 2;
FS_proto.onwritestart =
FS_proto.onprogress =
FS_proto.onwrite =
FS_proto.onabort =
FS_proto.onerror =
FS_proto.onwriteend =
null;
}(
typeof self !== "undefined" && self
|| typeof window !== "undefined" && window
|| this.content
));
// self is undefined in Firefox for Android content script context
// while this is nsIContentFrameMessageManager
// with an attribute content that corresponds to the window
module.exports.saveAs = saveAs;
} else if ((typeof define !== "undefined" && define !== null) && (define.amd !== null)) {
define("FileSaver.js",function() {
return saveAs;
});
}相关推荐
