CODEWITHSUNDEEP
javascriptscopephantomjscasperjs
Hommer Smith
Hommer Smith

Reputation: 27852

How to call another function from the function that is passed to evaluate in CasperJS

Here is what I am trying to do:

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

casper.start('mysite.html', function() {
});

/* Casper configuration */

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

function getAllImages()
{
    // Get all images
    var images = document.getElementsByTagName('img'); 
    evaluateImages(images);
}

function evaluateImages(images)
{
    console.log("I am in evaluateImages");
}

// Then find all pictures
casper.then(function() {
    var product_image = this.evaluate(getAllImages);
});

casper.run();

But it never gets to evaluteImages function. What am I missing here?

Upvotes: 2

Views: 2412

Answers (1)

plalx
plalx

Reputation: 43718

Well, I have never used CasperJS, however from what i've read in the docs, I believe that it's because the evaluateImages function doesn't exist in the page's context.

I am not sure what's the best practice here, however it seems that you can return primitives from evaluate callbacks, so you could technically do something like:

function getAllImages() {
    // Get all images
    var images = document.getElementsByTagName('img');

    //Return an array that contains all images src attribute
    return Array.prototype.map.call(images, function (img) {
        return img.src;
    });
}

Then you can do something like:

var images = this.evaluate(getAllImages);

evaluateImages(images);

EDIT:

I need to treat all the images in the page context, as I am comparing each of them with other elements that are in the page...

Perhaps you could define a module in the page's context first:

this.evaluate(function () {
    window.yourNS = {
        evaluateImages: function (images) {
            //do something with images
        },
        getAllImages: function () {
            return document.getElementsByTagName('img');
        }
    };
});

Then you can do something like:

this.evaluate(function () {
    yourNS.evaluateImages(yourNS.getAllImages());
});

Upvotes: 4

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