javascript - Passing variable from this.evaluate to casper.then - Stack Overflow

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I must have lost my mind on this but why it didn't print out "1: Google Search" and "2: Google Search"? Basically: how do I get a variable within this.evaluate and use it in the rest of casper.js scope?

var casper = require("casper").create();
var buttonText;

casper.start("");

casper.then(function() {
  buttonText = this.evaluate(function () {
    var myTxt = document.querySelector('#gbqfsa').innerText;
    console.log('1: ' + myTxt);

    return myTxt;
  }); 
});

casper.then(function() {
  this.echo('2: ' + buttonText);
});

casper.on('remote.message', function(msg) {
    this.echo('remote message caught: ' + msg);
});

casper.run();

I am using these libraries here:

.html

I must have lost my mind on this but why it didn't print out "1: Google Search" and "2: Google Search"? Basically: how do I get a variable within this.evaluate and use it in the rest of casper.js scope?

var casper = require("casper").create();
var buttonText;

casper.start("http://google.");

casper.then(function() {
  buttonText = this.evaluate(function () {
    var myTxt = document.querySelector('#gbqfsa').innerText;
    console.log('1: ' + myTxt);

    return myTxt;
  }); 
});

casper.then(function() {
  this.echo('2: ' + buttonText);
});

casper.on('remote.message', function(msg) {
    this.echo('remote message caught: ' + msg);
});

casper.run();

I am using these libraries here:

https://github./ariya/phantomjs

http://casperjs/index.html

• javascript
• webkit
• scope
• phantomjs
• casperjs

Share Improve this question Follow asked Dec 9, 2012 at 7:55 HP.HP. 19.9k5656 gold badges159159 silver badges258258 bronze badges

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3 Answers 3

Sorted by: Reset to default 9

The problem is that Google seems to be serving different versions when browsed with different user agents, for some very obscure reason. I'm suspecting heavy browser/user agent sniffing.

In our case, playing with Casper.debugHTML() shows that the code doesn't contain the button matching the #gbqfsa selector (while Chrome shows one); instead a standard submit <input name="btnG"> is there.

So here's your script using the actual selector for the button:

var casper = require("casper").create();
var buttonText;

casper.start("http://google./", function() {
    buttonText = this.evaluate(function () {
        var myTxt = document.querySelector('input[name="btnG"]').getAttribute('value');
        __utils__.echo('1: ' + myTxt);
        return myTxt;
    });
    this.echo('2: ' + buttonText);
});

casper.run();

Just an idea, try to use Casper.userAgent() to set the UA to something more mon, eg. a recent chrome version.

PS: also notice the use of __utils__.echo() to print stuff directly from within evaluate().

Edit: It works by setting a mon UA:

casper.start();

casper.userAgent("Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US) AppleWebKit/534.16 (KHTML, like Gecko) Chrome/10.0.648.204 Safari/534.16");

casper.thenOpen('http://google./', function() {
    this.test.assertExists('#gbqfsa'); // PASS
});

casper.run(function() {
    this.test.done();
});

I think there is serious issue with casper.js or phantom.js about debugging within evaluate(). If I replace below line, it works

var myTxt = document.querySelector('.gbts').innerHTML;

The question is: how to debug when there are javascript errors within evaluate()? There is no way to know...

Did you try this for debugging?

casper.on('remote.message', function(message) {
    this.echo('remote console message: ' + message);
});

Have a look at Events & filters - hooking & altering the CasperJS environment at runtime.

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