纯前端导出word文档(含样式、图片、canvas等元素)
丁某 2024-10-16 10:03:02 阅读 78
前言
有需要不依赖后端的情况下将网页原封不动的导出为word文档, 就写了这个工具函数。
思路
删除隐藏的或者排除的元素将所有样式转化为行内样式将图片和canvas转为Base64编码, 一起导入word中前端生成word有固定的头部模版, 替换内容为innerHTML即可导出work文档, 且保留行内样式手(复)写(制)的saveAs
使用技术
前端：JAVASCRIPT依赖: 无
开始操作
前端
将所有元素打标记, 然后放入iframe中, 这样不会影响原来的元素
<code>// 设置标记, 方便复制样式
Array.from(contEl.querySelectorAll('*')).forEach((item) => { -- -->
item.setAttribute('data-toword', Math.random().toString(32).slice(-5))
})
if (!window.contIframe) {
window.contIframe = document.createElement('iframe')
window.contIframe.style = 'display: none; width:100%;'
document.body.appendChild(window.contIframe)
}
let cloneEl = contEl.cloneNode(true)
cloneEl.style.width = getComputedStyle(contEl).width
window.contIframe.contentDocument.body.appendChild(cloneEl)
let domWrap = cloneEl
1. 删除隐藏的元素, 并且将元素样式设置为行内样式, 方便word识别
Array.from(domWrap.querySelectorAll('*')).forEach((item) => {
let attr = item.getAttribute('data-toword')
let originItem = contEl.querySelector('[data-toword="' + attr + '"]')code>
if (originItem) { -- -->
let sty = getComputedStyle(originItem)
if (sty.display == 'none ') return item.remove()
setStyle(item, sty)
}
})
// 1.1 删除排除的元素
if (Array.isArray(options.exclude) && options.exclude.length) {
options.exclude.forEach(ext => {
Array.from(domWrap.querySelectorAll(ext)).forEach((item) => item.remove())
})
}
将图片和canvas转为Base64编码
let imgList = domWrap.querySelectorAll('img')
console.log('加载图片数量: ', imgList.length)
await Promise.all(Array.from(imgList).filter(x => !x.src.startsWith('data')).map(tempimg => {
let img = new Image()
img.setAttribute('crossOrigin', 'anonymous')
img.src = options.proxyHost ? tempimg.src.replace(location.host, options.proxyHost) : tempimg.src
return new Promise((resolve, reject) => {
try {
img.onload = function () {
img.onload = null
const cw = Math.min(img.width, options.maxWidth)
const ch = img.height * (cw / img.width)
const canvas = document.createElement("CANVAS")
canvas.width = cw
canvas.height = ch
const context = canvas.getContext('2d')
context?.drawImage(img, 0, 0, cw, ch)
const uri = canvas.toDataURL("image/jpg", 0.8)
tempimg.src = uri
const w = Math.min(img.width, 550, options.maxWidth) // word图片最大宽度
tempimg.width = w
tempimg.height = img.height * (w / img.width)
console.log('img onload...', options.fileName, img.src, img.width, img.height, cw, ch, w, tempimg.height)
canvas.remove()
resolve(img.src)
}
img.onerror = function() {
console.log('img load error, ', img.src)
resolve('')
}
} catch (e) { console.log(e);resolve('') }
})
}))
// 将canvas转为Base64编码, 方便word保存
let canvasList = domWrap.querySelectorAll('canvas')
console.log('加载canvas数量: ', canvasList.length)
await Promise.all(Array.from(canvasList).map(tempCanvas => {
let img = new Image()
img.setAttribute('crossOrigin', 'anonymous');
return new Promise((resolve, reject) => {
try {
let attr = tempCanvas.getAttribute('data-toword')
let cvs = contEl.querySelector('[data-toword="' + attr + '"]')code>
console.log(cvs, attr);
if (!cvs) return resolve()
img.src = cvs.toDataURL("image/jpg", 0.8)
const w = Math.min(cvs.width, options.maxWidth)
const h = cvs.height * (w / cvs.width)
img.width = w
img.height = h
const parent = tempCanvas.parentNode
if (tempCanvas.nextSibling) { -- -->
parent.insertBefore(img, tempCanvas.nextSibling)
} else {
parent.appendChild(img)
}
tempCanvas.remove()
resolve('')
} catch (e) { console.log(e);resolve('') }
})
}))
将html内容写入word模版中并导出下载
let topstr = 'xmlns:v=\"urn:schemas-microsoft-com:vml\" xmlns:o=\"urn:schemas-microsoft-com:office:office\" xmlns:w=\"urn:schemas-microsoft-com:office:word\" xmlns:m=\"http://schemas.microsoft.com/office/2004/12/omml\" xmlns=\"http://www.w3.org/TR/REC-html40\"'
let headstr = '<!--[if gte mso 9]><xml><w:WordDocument><w:View>Print</w:View><w:TrackMoves>false</w:TrackMoves><w:TrackFormatting/><w:ValidateAgainstSchemas/><w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid><w:IgnoreMixedContent>false</w:IgnoreMixedContent><w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText><w:DoNotPromoteQF/><w:LidThemeOther>EN-US</w:LidThemeOther><w:LidThemeAsian>ZH-CN</w:LidThemeAsian><w:LidThemeComplexScript>X-NONE</w:LidThemeComplexScript><w:Compatibility><w:BreakWrappedTables/><w:SnapToGridInCell/><w:WrapTextWithPunct/><w:UseAsianBreakRules/><w:DontGrowAutofit/><w:SplitPgBreakAndParaMark/><w:DontVertAlignCellWithSp/><w:DontBreakConstrainedForcedTables/><w:DontVertAlignInTxbx/><w:Word11KerningPairs/><w:CachedColBalance/><w:UseFELayout/></w:Compatibility><w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel><m:mathPr><m:mathFont m:val=\"Cambria Math\"/><m:brkBin m:val=\"before\"/><m:brkBinSub m:val=\"--\"/><m:smallFrac m:val=\"off\"/><m:dispDef/><m:lMargin m:val=\"0\"/> <m:rMargin m:val=\"0\"/><m:defJc m:val=\"centerGroup\"/><m:wrapIndent m:val=\"1440\"/><m:intLim m:val=\"subSup\"/><m:naryLim m:val=\"undOvr\"/></m:mathPr></w:WordDocument></xml><![endif]-->'
let mhtml = {
top: "Mime-Version: 1.0\nContent-Base: " + location.href + "\nContent-Type: Multipart/related; boundary=\"NEXT.ITEM-BOUNDARY\";type=\"text/html\"\n\n--NEXT.ITEM-BOUNDARY\nContent-Type: text/html; charset=\"utf-8\"\nContent-Location: " + location.href + `\n\n<!DOCTYPE html>\n<html ${ topstr}>\n_html_</html>`,
head: `<head>\n<meta http-equiv=\"Content-Type\" content=\"text/html; charset=utf-8\">\n${ headstr}\n<style>\n_styles_\n</style>\n</head>\n`,
body: "<body>_body_</body>"
};
let exthtml = (options.title ? `<h1 style="text-align:center">${ -- -->options.title}</h1>` : '') + (options.time ? `<p style="text-align:center">${ -- -->options.time}</p>` : '')code>
let styles = "";
let fileContent = mhtml.top.replace("_html_", mhtml.head.replace("_styles_", styles) + mhtml.body.replace("_body_", exthtml + domWrap.innerHTML));
let blob = new Blob([fileContent], { -- --> type: "application/msword;charset=utf-8" });
console.log('即将生成文件大小: ', blob.size, (blob.size / 1024 / 1024).toFixed(2) + 'M');
if (options.blob) return blob
saveAs(blob, options.fileName + ".doc");
saveAs
export function saveAs(blob, fileName) {
var URL = window.URL || window.webkitURL;
var a = document.createElement('a');
fileName = fileName || blob.name || 'download';
a.download = fileName;
a.rel = 'noopener';
a.target = '_blank'
if (typeof blob === 'string') {
a.href = blob;
a.click()
} else {
a.href = URL.createObjectURL(blob);
setTimeout(() => a.click(), 0);
setTimeout(() => URL.revokeObjectURL(a.href), 2E4); // 20s
}
}
使用
详见example/index.html
<script src="../dist/export-doc.js"></script>code>
<script>
ExportDoc.toWord('#test-word', { -- -->
title: '关于导出王麻子这件事情',
time: '2024年8月15日 上午10点',
fileName: '剑来.doc',
exclude: ['.not-export', '.not-export1']
})
</script>
后言
将元素移入新的iframe并且保留样式思考了下, 且canvas在cloneNode的时候不会将内容拷贝过去, 这点采坑后期将完善纯前端导出excel
源码地址
源码和程序截图详见https://github.com/dhjz/export-doc示例 http://199311.xyz/export-doc/example/index.html
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