CasperJS

Question

我的页面 A 有 9 个弹出窗口 link，我需要从每个弹出窗口中提取信息。在此之后，我需要 return 到页面 A 并继续处理它。

我在 for 循环中使用了 waitForPopup 和 withPopup，我认为这是打开和关闭每个弹出窗口的正确方法。但奇怪的是，我从第一个弹出窗口中得到的信息重复了 9 次。我花了整整一夜才把它弄好，但被卡住了。请在下面查看我的代码。谢谢。

更新我发现 link 说明了确切的问题。 Casperjs - Is ThenClick Or Any 'then Function' Synchronized Function?

Inside my script, there is a while loop, I discover my script will jump to the end of while loop just before the thenClick

供您参考：

1> The code is part of the var suite_1 = function() { ...my code... }

2> The regex /fulltext/ here is based on the popup links 
(only the Gid value varies), like url=http://www.***.com/fulltext_form.aspx&Gid=788...

3> I also have some debug info.

[debug] [phantom] Mouse event 'mousedown' on selector: xpath selector: (//a[@class="main-ljwenzi"])[9]
[debug] [phantom] Mouse event 'mouseup' on selector: xpath selector: (//a[@class="main-ljwenzi"])[9]
[debug] [phantom] Mouse event 'click' on selector: xpath selector: (//a[@class="main-ljwenzi"])[9]
[debug] [phantom] Navigation requested: url=http://www.***.com/fulltext_form.aspx&Gid=788, type=LinkClicked, willNavigate=true, isMainFrame=false

...和...

[info] [phantom] Step anonymous 119/122 http://www.***.com/fulltext_form.aspx&Gid=252923 (HTTP 200)

The program is expected to open the link with Gid=788, but after some _step, it still open the Gid=252923, which is the first popup.

代码

this.then(function() {

    var count = this.getElementsInfo('a.main').length;
    this.echo(count + ' fulltext links found:', 'INFO');

    for (var i = 1; i < count + 1; i++) {

    //According to the output,
the program will run the this.capture 9 times,
before run the following lines of code 9 times

        this.capture('before the click - ' + i + '.png');

        this.thenClick(x('(//a[@class="main"])[' + i + ']'));

        this.waitForPopup(/fulltext/, function() {
            this.echo('Popup opened', 'INFO');
            this.echo(this.getTitle(), 'INFO');
        }, null, 10000);

        this.withPopup(/fulltext/, function() {

            this.echo(this.getTitle(), 'INFO');
            this.waitForSelector('#tbl_content_main', function() {
                // do something
            });
        });

        this.then(function() {
            this.echo('Back to the main page' + this.getTitle(), 'INFO_BAR');
        });
    }
});

Answer 1

我做了一个简单的例子来测试你的情况：

HTML(popup.html):

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div>
    <button class="popup" id="casperjs" onclick="javascript:window.open('http://casperjs.org/')">casperjs</button>
    <button class="popup" id="phantomjs" onclick="javascript:window.open('http://phantomjs.org/')">phantomjs</button>
    <button class="popup" id="nodejs" onclick="javascript:window.open('https://nodejs.org/')">nodejs</button>
</div>
</body>
</html>

代码：

var casper = require('casper').create();

casper.start('http://localhost:63342/popup.html')

casper.then(function () {
    var count = casper.getElementsInfo('.popup').length
    var counter = 1
    for (var i = 0; i < count; i++) {
        casper.then(function () {
            var selector = 'body > div > button:nth-child(' + counter + ')';
            var text = casper.getElementInfo(selector).text
            casper.click(selector)
            casper.waitForPopup(text, undefined, undefined, 20000)
            casper.withPopup(text, function () {
                casper.echo(casper.getTitle())
            })
            counter ++
        })
    }
})

casper.run()

输出：

$ casperjs popup.js 
CasperJS, a navigation scripting and testing utility for PhantomJS and SlimerJS
PhantomJS | PhantomJS
Node.js

它按预期工作。

所以，你的代码有两个问题：

应该将 for 循环内的整个代码包装到 then 中。
应该使用另一个计数器而不是 i 来制作选择器（您可以回显 i 的值以查看它始终是 count。在我的例子中，它是 3）。

与thenClick无关。您可以将我的示例代码中的 click 替换为 thenClick，一切都保持不变......如果您看一下 thenClick 的实现，您会发现我背后的原因声明...

试试这个：

this.then(function() {

    var count = this.getElementsInfo('a.main').length;
    this.echo(count + ' fulltext links found:', 'INFO');
    var counter = 1 // +
    for (var i = 1; i < count + 1; i++) {
        this.then(function() { //+
            this.capture('before the click - ' + counter + '.png');//edit

            this.thenClick(x('(//a[@class="main"])[' + counter + ']'));//edit

            this.waitForPopup(/fulltext/, function() {
                this.echo('Popup opened', 'INFO');
                this.echo(this.getTitle(), 'INFO');
            }, null, 10000);

            this.withPopup(/fulltext/, function() {

                this.echo(this.getTitle(), 'INFO');
                this.waitForSelector('#tbl_content_main', function() {
                    // do something
                });
            });

            this.then(function() {
                this.echo('Back to the main page' + this.getTitle(), 'INFO_BAR');
            });
            counter ++ //+
        })//+
    }
});

如果你对为什么要使用另一个计数器感到好奇，你可以在另一个上阅读我的回答。

CasperJS - 在抓取所有弹出窗口后循环访问页面 A 上的弹出链接并 return 到页面 A？

CasperJS - Loop over popup links on Page A and return to Page A after scraping all popups?

javascript

web-scraping