How can I inject JS and collect alert message from website?
Question
I am trying to collect alert from website by using overwrite method. I searched on google and found wappalyzer , a Chrome/Firefox extension to detect software on website. It injects a script inject.js when page load and collect information. My method is similar. I make a local website and test it. When I inject overwrite_alert.js manually then it works.
But I want to do it dynamically and apply to other website. So I use headless browser like PhantomJS. The following code which I tried in PhantomJS but it does not work.
I am trying to inject a JavaScript on phantom JS. Like this code:
<!DOCTYPE html>
<html>
<head>
<title>Test alert</title>
<!-- !!! Inject here !!! <script src="overwrite_alert.js"></script> -->
<script type="text/javascript" src="other_script.js"> </script>
<script type="text/javascript">
alert("Alert content");
</script>
</head>
<body>
<h1>website content</h1>
</body>
</html>
overwrite_alert.js file from this question :
(function() {
var _alert = window.alert; // <-- Reference
window.alert = function(str) {
// do something additional
if(console) console.log(str);
//return _alert.apply(this, arguments); // <-- The universal method
_alert(str); // Suits for this case
};
})();
I tried with onLoadStarted event and My PhantomJS code:
var webPage = require('webpage');
var page = webPage.create();
var url = "https://localhost:5000/alert.html";
page.onConsoleMessage = function(msg, lineNum, sourceId) {
console.log('CONSOLE> ' + msg);
};
page.onLoadStarted = function() {
if (page.injectJs('do.js')) {
var title = page.evaluate(function() {
// returnTitle is a function loaded from our do.js file - see below
console.log("evaluate completed");
});
console.log(title);
}
}
page.open(url, function(status) {
if (status === "success") {
if (page.injectJs('do.js')) {
var title = page.evaluate(function() {
// returnTitle is a function loaded from our do.js file - see below
console.log("evaluate completed");
});
console.log(title);
phantom.exit();
}
page.render("onOpen.png");
}
});
Result:
$ phantomjs test_inject.js
CONSOLE> from onLoadStarted completed
null
CONSOLE> from page.open
null
1 answers
solution1
0 ACCPTED 2016-05-26 05:11:47
Since the page.open callback is called after a page is loaded, it would be simply to late to change the implementation of window.alert . You would need to use earlier events such as page.onInitialized , page.onLoadStarted , etc.
Since you're interested in alerts, you don't need to do that at all, because PhantomJS provides an event for that: page.onAlert
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.