I'm developing an electronic invoicing system, and one of our features is generating PDFs of the invoices, and mailing them. We have multiple templates for invoices, and will create more later, so we decided to use HTML templates, generate HTML document, and then convert it to PDF. But we're facing a problem with wkhtmltopdf, that as far as I know (I've been Googleing for days to find the solution) we cannot simply both use HTML as header/footer, and show page numbers in them.
In a bug report (or such) ( http://code.google.com/p/wkhtmltopdf/issues/detail?id=140 ) I read that with JavaScript it is achievable this combo. But no other information on how to do it can be found on this page, or elsewhere.
It is, of course not so important to force using JavaScript, if with wkhtmltopdf some CSS magic could work, it would be just as awesome, as any other hackish solutions.
Thanks!
To show the page number and total pages you can use this javascript snippet in your footer or header code:
var pdfInfo = {};
var x = document.location.search.substring(1).split('&');
for (var i in x) { var z = x[i].split('=',2); pdfInfo[z[0]] = unescape(z[1]); }
function getPdfInfo() {
var page = pdfInfo.page || 1;
var pageCount = pdfInfo.topage || 1;
document.getElementById('pdfkit_page_current').textContent = page;
document.getElementById('pdfkit_page_count').textContent = pageCount;
}
And call getPdfInfo with page onload
Of course pdfkit_page_current and pdfkit_page_count will be the two elements that show the numbers.
Snippet taken from here
Actually it's much simpler than with the code snippet. You can add the following argument on the command line: --footer-center [page]/[topage].
Like richard mentioned, further variables are in the Footers and Headers section of the documentation.
Among a few other parameters, the page number and total page number are passed to the footer HTML as query params, as outlined in the official docs:
... the [page number] arguments are sent to the header/footer html documents in GET fashion.
Source: http://wkhtmltopdf.org/usage/wkhtmltopdf.txt
So the solution is to retrieve these parameters using a bit of JS and rendering them into the HTML template. Here is a complete working example of a footer HTML:
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<script>
function substitutePdfVariables() {
function getParameterByName(name) {
var match = RegExp('[?&]' + name + '=([^&]*)').exec(window.location.search);
return match && decodeURIComponent(match[1].replace(/\+/g, ' '));
}
function substitute(name) {
var value = getParameterByName(name);
var elements = document.getElementsByClassName(name);
for (var i = 0; elements && i < elements.length; i++) {
elements[i].textContent = value;
}
}
['frompage', 'topage', 'page', 'webpage', 'section', 'subsection', 'subsubsection']
.forEach(function(param) {
substitute(param);
});
}
</script>
</head>
<body onload="substitutePdfVariables()">
<p>Page <span class="page"></span> of <span class="topage"></span></p>
</body>
</html>
substitutePdfVariables() is called in body onload. We then get each supported variable from the query string and replace the content in all elements with a matching class name.
From the wkhtmltopdf documentation (http://madalgo.au.dk/~jakobt/wkhtmltoxdoc/wkhtmltopdf-0.9.9-doc.html) under the heading "Footers and Headers" there is a code snippet to achieve page numbering:
<html><head><script>
function subst() {
var vars={};
var x=document.location.search.substring(1).split('&');
for(var i in x) {var z=x[i].split('=',2);vars[z[0]] = unescape(z[1]);}
var x=['frompage','topage','page','webpage','section','subsection','subsubsection'];
for(var i in x) {
var y = document.getElementsByClassName(x[i]);
for(var j=0; j<y.length; ++j) y[j].textContent = vars[x[i]];
}
}
</script></head><body style="border:0; margin: 0;" onload="subst()">
<table style="border-bottom: 1px solid black; width: 100%">
<tr>
<td class="section"></td>
<td style="text-align:right">
Page <span class="page"></span> of <span class="topage"></span>
</td>
</tr>
</table>
</body></html>
There are also more available variables which can be substituted other than page numbers for use in Headers/Footers.
The way it SHOULD be done (that is, if wkhtmltopdf supported it) would be using proper CSS Paged Media: http://www.w3.org/TR/css3-gcpm/
I'm looking into what it will take now.
Safe approach, even if you are using XHTML (for example, with thymeleaf). The only difference with other's solution is the use of // tags.
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8"/>
<script>
/*<![CDATA[*/
function subst() {
var vars = {};
var query_strings_from_url = document.location.search.substring(1).split('&');
for (var query_string in query_strings_from_url) {
if (query_strings_from_url.hasOwnProperty(query_string)) {
var temp_var = query_strings_from_url[query_string].split('=', 2);
vars[temp_var[0]] = decodeURI(temp_var[1]);
}
}
var css_selector_classes = ['page', 'topage'];
for (var css_class in css_selector_classes) {
if (css_selector_classes.hasOwnProperty(css_class)) {
var element = document.getElementsByClassName(css_selector_classes[css_class]);
for (var j = 0; j < element.length; ++j) {
element[j].textContent = vars[css_selector_classes[css_class]];
}
}
}
}
/*]]>*/
</script>
</head>
<body onload="subst()">
<div class="page-counter">Page <span class="page"></span> of <span class="topage"></span></div>
</body>
Last note: if using thymeleaf, replace <script> with <script th:inline="javascript">.
来源：https://stackoverflow.com/questions/7174359/how-to-do-page-numbering-in-header-footer-htmls-with-wkhtmltopdf