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I would like to count the number of, let's say, div elements with 'nice' class. I've got the selector div.nice, but don't know which casperjs class/method to use.

There is a tester.assertElementCount method in fact, but is there anything that simply returns the number of elements?

I would like to count the number of, let's say, div elements with 'nice' class. I've got the selector div.nice, but don't know which casperjs class/method to use.

There is a tester.assertElementCount method in fact, but is there anything that simply returns the number of elements?

• javascript
• dom
• phantomjs
• casperjs

Share Improve this question Follow asked Aug 5, 2013 at 15:33 ducinducin 26.5k4444 gold badges166166 silver badges261261 bronze badges 1

• I think you have to create your own function for this. It looks like the easiest way t do this is to check if the element exists and use the css ":nth-of-type(i)". I posted an answer below for this. – user1816910 Commented Feb 10, 2017 at 5:42

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6 Answers 6

Sorted by: Reset to default 5

Just

document.querySelectorAll("div.nice").length

If you can use jquery its fairly simple:

var count = $('div.classname').length;

Found an SO Post that seems to explain using jquery with casperjs, I have no experience with casperjs so I can't help much there.

One of the examples for CasperJS 1.1-beta3 involves checking the number of Google search results for CasperJS. It references __utils__.findAll(), which takes a selector as its argument. It allows you to check the number of items returned using the length property available to any JS object:

test.assertEval(function() {
  return __utils__.findAll("h3.r").length >= 10;
}, "google search for \"casperjs\" retrieves 10 or more results");

I've never tried it, but it seems like this utility function can be used outside a conditional, and it will allow you to report the number of elements without using jQuery, as a previous answer remended.

Casper provides getElementsInfo, you can use the attribute length to get the number of elements. e.g.

casper.getElementsInfo('myElement').length

you also can use assertElementCount to assert the count of the elment

test.assertElementCount("div.nice", 1)

I did not find the answers above to be helpful to my cause.

I think the goal was to count the number of elements without having to evaluate the js code in the page context, which could be frustrating overtime and have conflicting variables and functions.

Instead, it would be nice to leverage the casper automation context. This can be done with a bination of ".exists()" and the css psuedo-selector ":nth-of-type(i)"

The code below does this...

var counter = 1;          //set to one, for css selector setup

casper.then(function() {  //wait your turn
    //loop through our element
    while(casper.exists( 'div span:nth-of-type(' + counter + ')' )) {
        counter++;        //count the results
    }
});

You could make this a function and pass in all the arguments, or just copy and paste it as a step.

Best part, you could follow it with a repeat statement for a pretty cool loop.

casper.then(function(){
    this.repeat(counter, function() {
        console.log("Another one - item #" + counter);
    });
});

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