页脚的内容似乎无效

本文介绍了页脚的内容似乎无效的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我正在尝试在phantomjs示例中创建自定义页脚: https: //github/ariya/phantomjs/blob/master/examples/printheaderfooter.js

I'm trying create custom footers such in phantomjs examples: github/ariya/phantomjs/blob/master/examples/printheaderfooter.js

这是我的代码:

var phantom = require('node-phantom'); phantom.create(function (err, ph) { ph.createPage(function (err, page) { page.set('paperSize', { format: 'A4', orientation: 'portrait', footer: { contents: ph.callback(function (pageNum, numPages) { if (pageNum == 1) { return ""; } return "<h1>Header <span style='float:right'>" + pageNum + " / " + numPages + "</span></h1>"; }) } }, function () { page.open('www.google', function () { }) }) }) });

但不幸的是，我收到以下错误消息:

But unfortunately I get the following error:

TypeError: Object #<Object> has no method 'callback';

ph不公开回调方法是错误的吗?

Is it bug that ph does not expose callback method?

推荐答案

脚本中存在两个问题:

• ph不是经典的幻像对象，而是代理对象. node-phantom使用Web套接字调用phantomjs.当然，使用此实现会丢失某些功能.
调用page.set 时
• 函数未序列化

• ph is not the classic phantom object, but a proxy object. node-phantom use web sockets to invoke phantomjs. Of course, some features are lost using this implementation.
• functions are not serialized when calling page.set

打印自定义页眉/页脚还需要调用phantom.callback.此方法没有记录，因此没有被node-phantom公开(并且不能公开).我们需要找到一种在此程序包中应用此方法的方法.

Printing custom header/footer also requires to call phantom.callback. This method is not documented and so not exposed by node-phantom (and can't be). We need to find a way to apply this method in this package.

有很多解决方案.这是我可能的解决方法:

There are many solutions. Here is my possible solution :

在脚本中的字符串中序列化您的函数

Serialize your functions in a string in your script

var phantom = require('node-phantom'); phantom.create(function (err, ph) { ph.createPage(function (err, page) { page.set('paperSize', { format: 'A4', orientation: 'portrait', header: { height: "1cm", contents: 'function(pageNum, numPages) { return pageNum + "/" + numPages; }' }, footer: { height: "1cm", contents: 'function(pageNum, numPages) { return pageNum + "/" + numPages; }' } }, function () { page.open('www.google.fr', function () { page.render('google.pdf'); ph.exit(); }) }) }) });

编辑bridge.js并添加phantom.callback + eval.这样我们就可以重新插入header/footer .contents.

edit bridge.js and add phantom.callback + eval. This allow us to re-plug the header/footer .contents.

case 'pageSet': eval('request[4].header.contents = phantom.callback('+request[4].header.contents+')'); eval('request[4].footer.contents = phantom.callback('+request[4].footer.contents+')'); page[request[3]]=request[4]; respond([id,cmdId,'pageSetDone']); break;

如您所见，这行得通！ (法语的Google)

As you can see this works ! (Google in French)