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遇到了需要将页面内容导出为word的需求,本以为是个简单的需求,却折腾了一天,主要难点在css样式和echarts图表的导出,wordexport.js插件的使用非常简单:
导出内容
$("#content").wordExport("文件名");
这样就可以导出content 里的内容,但是你会发现页面上呈现的样式并没有展示在word里,这里需要改动wordexport.js的部分代码来实现样式表的导入,下面是源码(改动后):
if (typeof jQuery !== "undefined" && typeof saveAs !== "undefined") {
(function($) {
$.fn.wordExport = function(fileName,rule) {
fileName = typeof fileName !== 'undefined' ? fileName : "jQuery-Word-Export";
var static = {
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\n\n_html_",
head: "
\n\n\n\n",body: "
_body_"}
};
var options = {
maxWidth: 624
};
// Clone selected element before manipulating it
var markup = $(this).clone();
// Remove hidden elements from the output
markup.each(function() {
var self = $(this);
if (self.is(':hidden'))
self.remove();
});
// Embed all images using Data URLs
var images = Array();
var img = markup.find('img');
for (var i = 0; i < img.length; i++) {
// Calculate dimensions of output image
var w = Math.min(img[i].width, options.maxWidth);
var h = img[i].height * (w / img[i].width);
// Create canvas for converting image to data URL
var canvas = document.createElement("CANVAS");
canvas.width = w;
canvas.height = h;
// Draw image to canvas
var context = canvas.getContext('2d');
context.drawImage(img[i], 0, 0, w, h);
// Get data URL encoding of image
var uri = canvas.toDataURL("image/png");
$(img[i]).attr("src", img[i].src);
img[i].width = w;
img[i].height = h;
// Save encoded image to array
images[i] = {
type: uri.substring(uri.indexOf(":") + 1, uri.indexOf(";")),
encoding: uri.substring(uri.indexOf(";") + 1, uri.indexOf(",")),
location: $(img[i]).attr("src"),
data: uri.substring(uri.indexOf(",") + 1)
};
}
// Prepare bottom of mhtml file with image data
var mhtmlBottom = "\n";
for (var i = 0; i < images.length; i++) {
mhtmlBottom += "--NEXT.ITEM-BOUNDARY\n";
mhtmlBottom += "Content-Location: " + images[i].location + "\n";
mhtmlBottom += "Content-Type: " + images[i].type + "\n";
mhtmlBottom += "Content-Transfer-Encoding: " + images[i].encoding + "\n\n";
mhtmlBottom += images[i].data + "\n\n";
}
mhtmlBottom += "--NEXT.ITEM-BOUNDARY--";
//TODO: load css from included stylesheet
//源码将styles置为"",这里我们只需改动成传入css,赋值给styles即可;
var styles = rule || "";
// Aggregate parts of the file together
var fileContent = static.mhtml.top.replace("_html_", static.mhtml.head.replace("_styles_", styles) + static.mhtml.body.replace("_body_", markup.html())) + mhtmlBottom;
// Create a Blob with the file contents
var blob = new Blob([fileContent], {
type: "application/msword;charset=utf-8"
});
saveAs(blob, fileName + ".doc");
};
})(jQuery);
} else {
if (typeof jQuery === "undefined") {
console.error("jQuery Word Export: missing dependency (jQuery)");
}
if (typeof saveAs === "undefined") {
console.error("jQuery Word Export: missing dependency (FileSaver.js)");
}
}
如文中注释部分所言:源码将styles置为"",这里我们只需改动成传入css,赋值给styles即可;在调用的时候先将html中使用的css拼接成一个字符串,再传入该插件中:
var rules = "",
ss = document.styleSheets;
for (var i = 0; i < ss.length; ++i) {
for (var x = 0; x < ss[i].cssRules.length; ++x) {
rules += ss[i].cssRules[x].cssText;
}
}
$("#content").wordExport(name, rules);
如此一来,你将发现:一部分css样式生效了,比如文字的宽高和颜色等,然而还有很多样式没有生效:如大部分css3选择器~;这里是因为word上支持的样式有限导致的;
这就非常难受了,最开始我的页面上的表格使用dhtmlx构建,导出后不仅样式完全没有,而且发现dhtmlxGrid的表头和表体是两个table,这样在word里非常不好调整,于是我更换了dataTables插件,问题依然是样式没有生效;
于是我想到一个办法:既然是因为css3选择器不支持导致的,那将dom的样式取出来,写入html标签的style里是否可以解析:
var node = $("#container")[0];
var treeWalker = document.createTreeWalker(node, NodeFilter.SHOW_ELEMENT, null, false);
if(node && node.nodeType === 1) {
var rule = getComputedStyle(node);
$(node).attr("style", rule.cssText)
}
var node = treeWalker.nextNode();
while(node != null) {
var rule = getComputedStyle(node);
$(node).attr("style", rule.cssText)
node = treeWalker.nextNode();
}
测试以后果然可以,但是若是页面结构复杂,这种方法会很耗时,而且因为rule.cssText 得到的样式字符串很长,生成的word体积就很庞大,
解决思路:
可以只取出部分需要的样式信息,先列出页面所需的样式名数组,然后通过rule.样式名 的方式获取,这样可以去掉rule.cssText 中绝大部分的无用样式;
可以只对需要的部分结构进行以上操作,比如我的页面中只有表格样式加载不出,那我只需对所有表格追加style 即可;
因为项目时间紧迫,我没有实践以上思路,而是直接在wordexport.js中写入了word可以解析的table样式:
var rules = "table{border-collapse:collapse;margin:0 auto;text-align:center;width: 100%;}table td,table th{border:1px solid #cad9ea;color:#666;height:30px}table thead th{background-color:#F1F1F1;min-width:400px}table tr{background:#fff}",
ss = document.styleSheets;
for (var i = 0; i < ss.length; ++i) {
for (var x = 0; x < ss[i].cssRules.length; ++x) {
rules += ss[i].cssRules[x].cssText;
}
}
关于echarts图表的导出:word的导出会忽略很多dom结构,echarts的canvas正是其中之一,于是在这里我们需要先使用curEchart.getConnectedDataURL()将图表转为base64的编码的图片,然后指定img标签的src为获取到的base64字符串,这样就可以顺利导出图片啦~,下面是我最终的代码:
var rules = "table{border-collapse:collapse;margin:0 auto;text-align:center;width: 100%;}table td,table th{border:1px solid #cad9ea;color:#666;height:30px}table thead th{background-color:#F1F1F1;min-width:400px}table tr{background:#fff}",
ss = document.styleSheets;
for(var i = 0; i < ss.length; ++i) {
for(var x = 0; x < ss[i].cssRules.length; ++x) {
rules += ss[i].cssRules[x].cssText;
}
}
//先clone来避免影响页面显示
var clone = $("#container").clone();
//找到所有echarts图表容器
var charts = clone.find(".chart");
//隐藏无需导出的dom
clone.find(".input_div").hide();
//简单控制流程
var flag = charts.length;
for(var i = 0; i < charts.length; i++) {
//获取echarts对象
var curEchart = echarts.getInstanceByDom(charts[i]);
if(curEchart) {
//将图表替换为图片
var base = curEchart.getConnectedDataURL();
var img = $('');
$(charts[i]).html(img);
flag--;
} else {
flag--;
}
}
var interval = setInterval(function() {
if(!flag) {
clearInterval(interval);
//导出word
clone.wordExport(name, rules);
}
}, 200)