The casper module

The Casper class

The easiest way to get a casper instance is to use the module's create() method:

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

But you can also retrieve the main Function and instantiate it by yourself:

var casper = new require('casper').Casper();

Both the Casper constructor and the create() function accept a single options argument which is a standard javascript object:

var casper = require('casper').create({
    verbose: true,
    logLevel: "debug"
});

Casper.options

An options object can be passed to the Casper constructor, eg.:

var casper = require('casper').create({
    clientScripts:  [
        'includes/jquery.js',      // These two scripts will be injected in remote
        'includes/underscore.js'   // DOM on every request
    ],
    pageSettings: {
        loadImages:  false,        // The WebPage instance used by Casper will
        loadPlugins: false         // use these settings
    },
    logLevel: "info",              // Only "info" level messages will be logged
    verbose: true                  // log messages will be printed out to the console
});

You can also alter options at runtime:

var casper = require('casper').create();
casper.options.waitTimeout = 1000;

The whole list of available options is detailed below.

clientScripts

Type: Array

Default: []

A collection of script filepaths to include in every page loaded

exitOnError

Type: Boolean

Default: true

Sets if CasperJS must exit when an uncaught error has been thrown by the script.

httpStatusHandlers

Type: Object

Default: {}

A javascript Object containing functions to call when a requested resource has a given HTTP status code. A dedicated sample is provided as an example.

logLevel

Type: String

Default: "error"

Logging level (see the logging section for more information)

onAlert

Type: Function

Default: null

A function to be called when a javascript alert() is triggered

onDie

Type: Function

Default: null

A function to be called when Casper#die() is called

onError

Type: Function

Default: null

A function to be called when an "error" level event occurs

onLoadError

Type: Function

Default: null

A function to be called when a requested resource cannot be loaded

onPageInitialized

Type: Function

Default: null

A function to be called after WebPage instance has been initialized

onResourceReceived

Type: Function

Default: null

Proxy method for PhantomJS' WebPage#onResourceReceived() callback, but the current Casper instance is passed as first argument.

onResourceRequested

Type: Function

Default: null

Proxy method for PhantomJS' WebPage#onResourceRequested() callback, but the current Casper instance is passed as first argument.

onStepComplete

Type: Function

Default: null

A function to be executed when a step function execution is finished.

onStepTimeout

Type: Function

Default: Function

A function to be executed when a step function execution time exceeds the value of the stepTimeout option, if any has been set.

By default, on timeout the script will exit displaying an error, except in test environment where it will just add a failure to the suite results.

onTimeout

Type: Function

Default: Function

A function to be executed when script execution time exceeds the value of the timeout option, if any has been set.

By default, on timeout the script will exit displaying an error, except in test environment where it will just add a failure to the suite results.

onWaitTimeout

Type: Function

Default: Function

A function to be executed when a waitFor* function execution time exceeds the value of the waitTimeout option, if any has been set.

By default, on timeout the script will exit displaying an error, except in test environment where it will just add a failure to the suite results.

page

Type: WebPage

Default: null

An existing PhantomJS WebPage instance

pageSettings

Type: Object

Default: {}

PhantomJS's WebPage settings object. Available settings are:

• javascriptEnabled defines whether to execute the script in the page or not (default to true)
• loadImages defines whether to load the inlined images or not
• loadPlugins defines whether to load NPAPI plugins (Flash, Silverlight, …) or not
• localToRemoteUrlAccessEnabled defines whether local resource (e.g. from file) can access remote URLs or not (default to false)
• userAgent defines the user agent sent to server when the web page requests resources
• userName sets the user name used for HTTP authentication
• password sets the password used for HTTP authentication
• XSSAuditingEnabled defines whether load requests should be monitored for cross-site scripting attempts (default to false)

remoteScripts

Type: Array

Default: []

A collection of remote script urls to include in every page loaded

safeLogs

Type: Boolean

Default: true

When this option is set to true — which is the default, any password information entered in <input type="password"> will be obfuscated in log messages. Set safeLogs to false to disclose passwords in plain text (not recommended).

silentErrors

Type: Boolean

Default: false

When this option is enabled, caught step errors are not thrown (though related events are still emitted). Mostly used internally in a testing context.

stepTimeout

Type: Number

Default: null

Max step timeout in milliseconds; when set, every defined step function will have to execute before this timeout value has been reached. You can define the onStepTimeout() callback to catch such a case. By default, the script will die() with an error message.

timeout

Type: Number

Default: null

Max timeout in milliseconds

verbose

Type: Boolean

Default: false

Realtime output of log messages

viewportSize

Type: Object

Default: null

Viewport size, eg. {width: 800, height: 600}

retryTimeout

Type: Number

Default: 100

Default delay between attempts, for wait* family functions.

waitTimeout

Type: Number

Default: 5000

Default wait timeout, for wait* family functions.

Casper prototype

back()

Signature: back()

Moves back a step in browser's history:

casper.start('http://foo.bar/1')
casper.thenOpen('http://foo.bar/2');
casper.thenOpen('http://foo.bar/3');
casper.back();
casper.run(function() {
    console.log(this.getCurrentUrl()); // 'http://foo.bar/2'
});

Also have a look at forward().

base64encode()

Signature: base64encode(String url [, String method, Object data])

Encodes a resource using the base64 algorithm synchronously using client-side XMLHttpRequest.

Example: retrieving google logo image encoded in base64:

var base64logo = null;
casper.start('http://www.google.fr/', function() {
    base64logo = this.base64encode('http://www.google.fr/images/srpr/logo3w.png');
});

casper.run(function() {
    this.echo(base64logo).exit();
});

You can also perform an HTTP POST request to retrieve the contents to encode:

var base64contents = null;
casper.start('http://domain.tld/download.html', function() {
    base64contents = this.base64encode('http://domain.tld/', 'POST', {
        param1: 'foo',
        param2: 'bar'
    });
});

casper.run(function() {
    this.echo(base64contents).exit();
});

bypass()

Signature: bypass(Numbr nb)

Bypasses a given number of defined navigation steps:

casper.start();
casper.then(function() {
    // This step will be executed
});
casper.then(function() {
    this.bypass(2);
});
casper.then(function() {
    // This test won't be executed
});
casper.then(function() {
    // Nor this one
});
casper.run();

click()

Signature: click(String selector)

Performs a click on the element matching the provided :doc:`selector expression <../selectors>`. The method tries two strategies sequentially:

1. trying to trigger a MouseEvent in Javascript
2. using native QtWebKit event if the previous attempt failed

Example:

casper.start('http://google.fr/');

casper.thenEvaluate(function(term) {
    document.querySelector('input[name="q"]').setAttribute('value', term);
    document.querySelector('form[name="f"]').submit();
}, 'CasperJS');

casper.then(function() {
    // Click on 1st result link
    this.click('h3.r a');
});

casper.then(function() {
    console.log('clicked ok, new location is ' + this.getCurrentUrl());
});

casper.run();

clickLabel()

Signature: clickLabel(String label[, String tag])

Clicks on the first DOM element found containing label text. Optionaly ensures that the element node name is tag:

// <a href="...">My link is beautiful</a>
casper.then(function() {
    this.clickLabel('My link is beautiful', 'a');
});

// <button type="submit">But my button is sexier</button>
casper.then(function() {
    this.clickLabel('But my button is sexier', 'button');
});

capture()

Signature: capture(String targetFilepath, [Object clipRect, Object imgOptions])

Proxy method for PhantomJS' WebPage#render. Adds a clipRect parameter for automatically setting page clipRect setting and reverts it back once done:

casper.start('http://www.google.fr/', function() {
    this.capture('google.png', {
        top: 100,
        left: 100,
        width: 500,
        height: 400
    });
});

casper.run();

The imgOptions object allows to specify two options:

• format to set the image format manually, avoiding relying on the filename
• quality to set the image quality, from 1 to 100

Example:

casper.start('http://foo', function() {
    this.capture('foo', undefined, {
        format: 'jpg',
        quality: 75
    });
});

captureBase64()

Signature: captureBase64(String format[, Mixed area])

Computes the Base64 representation of a binary image capture of the current page, or an area within the page, in a given format.

Supported image formats are bmp, jpg, jpeg, png, ppm, tiff, xbm and xpm.

The area argument can be either of the following types:

• String: area is a CSS3 selector string, eg. div#plop form[name="form"] input[type="submit"]
• clipRect: area is a clipRect object, eg. {"top":0,"left":0,"width":320,"height":200}
• Object: area is a :doc:`selector object <../selectors>`, eg. an XPath selector

Example:

casper.start('http://google.com', function() {
    // selector capture
    console.log(this.captureBase64('png', '#lga'));
    // clipRect capture
    console.log(this.captureBase64('png', {
        top: 0,
        left: 0,
        width: 320,
        height: 200
    }));
    // whole page capture
    console.log(this.captureBase64('png'));
});

casper.run();

captureSelector()

Signature: captureSelector(String targetFile, String selector [, Object imgOptions])

Captures the page area containing the provided selector and saves it to targetFile:

casper.start('http://www.weather.com/', function() {
    this.captureSelector('weather.png', '#wx-main');
});

casper.run();

The imgOptions object allows to specify two options:

• format to set the image format manually, avoiding relying on the target filename
• quality to set the image quality, from 1 to 100

clear()

Signature: clear()

Clears the current page execution environment context. Useful to avoid having previously loaded DOM contents being still active.

Think of it as a way to stop javascript execution within the remote DOM environment:

casper.start('http://www.google.fr/', function() {
    this.clear(); // javascript execution in this page has been stopped
});

casper.then(function() {
    // ...
});

casper.run();

debugHTML()

Signature: debugHTML([String selector, Boolean outer])

Outputs the results of getHTML() directly to the console. It takes the same arguments as getHTML().

debugPage()

Signature: debugPage()

Logs the textual contents of the current page directly to the standard output, for debugging purpose:

casper.start('http://www.google.fr/', function() {
    this.debugPage();
});

casper.run();

die()

Signature: die(String message[, int status])

Exits phantom with a logged error message and an optional exit status code:

casper.start('http://www.google.fr/', function() {
    this.die("Fail.", 1);
});

casper.run();

download()

Signature: download(String url, String target[, String method, Object data])

Saves a remote resource onto the filesystem. You can optionally set the HTTP method using the method argument, and pass request arguments through the data object (see base64encode()):

casper.start('http://www.google.fr/', function() {
    var url = 'http://www.google.fr/intl/fr/about/corporate/company/';
    this.download(url, 'google_company.html');
});

casper.run(function() {
    this.echo('Done.').exit();
});

each()

Signature: each(Array array, Function fn)

Iterates over provided array items and execute a callback:

var links = [
    'http://google.com/',
    'http://yahoo.com/',
    'http://bing.com/'
];

casper.start().each(links, function(self, link) {
    self.thenOpen(link, function() {
        this.echo(this.getTitle());
    });
});

casper.run();

eachThen()

Signature: eachThen(Array array, Function then)

Iterates over provided array items and adds a step to the stack with current data attached to it:

casper.start().eachThen([1, 2, 3], function(response) {
    this.echo(response.data);
}).run();

Here's an example for opening an array of urls:

var casper = require('casper').create();
var urls = ['http://google.com/', 'http://yahoo.com/'];

casper.start().eachThen(urls, function(response) {
  this.thenOpen(response.data, function(response) {
    console.log('Opened', response.url);
  });
});

casper.run();

echo()

Signature: echo(String message[, String style])

Prints something to stdout, optionally with some fancy color (see the :ref:`colorizer module <colorizer_module>` for more information):

casper.start('http://www.google.fr/', function() {
    this.echo('Page title is: ' + this.evaluate(function() {
        return document.title;
    }), 'INFO'); // Will be printed in green on the console
});

casper.run();

evaluate()

Signature: evaluate(Function fn[, arg1[, arg2[, …]]])

Basically PhantomJS' WebPage#evaluate equivalent. Evaluates an expression in the current page DOM context:

casper.evaluate(function(username, password) {
    document.querySelector('#username').value = username;
    document.querySelector('#password').value = password;
    document.querySelector('#submit').click();
}, 'sheldon.cooper', 'b4z1ng4');

Understanding evaluate()

The concept behind this method is probably the most difficult to understand when discovering CasperJS. As a reminder, think of the evaluate() method as a gate between the CasperJS environment and the one of the page you have opened; everytime you pass a closure to evaluate(), you're entering the page and execute code as if you were using the browser console.

Here's a quickly drafted diagram trying to basically explain the separation of concerns:

evaluateOrDie()

Signature: evaluateOrDie(Function fn[, String message])

Evaluates an expression within the current page DOM and die() if it returns anything but true:

casper.start('http://foo.bar/home', function() {
    this.evaluateOrDie(function() {
        return /logged in/.match(document.title);
    }, 'not authenticated');
});

casper.run();

exit()

Signature: exit([int status])

Exits PhantomJS with an optional exit status code.

exists()

Signature: exists(String selector)

Checks if any element within remote DOM matches the provided :doc:`selector <../selectors>`:

casper.start('http://foo.bar/home', function() {
    if (this.exists('#my_super_id')) {
        this.echo('found #my_super_id', 'INFO');
    } else {
        this.echo('#my_super_id not found', 'ERROR');
    }
});

casper.run();

fetchText()

Signature: fetchText(String selector)

Retrieves text contents matching a given :doc:`selector expression <../selectors>`. If you provide one matching more than one element, their textual contents will be concatenated:

casper.start('http://google.com/search?q=foo', function() {
    this.echo(this.fetchText('h3'));
}).run();

forward()

Signature: forward()

Moves a step forward in browser's history:

casper.start('http://foo.bar/1')
casper.thenOpen('http://foo.bar/2');
casper.thenOpen('http://foo.bar/3');
casper.back();    // http://foo.bar/2
casper.back();    // http://foo.bar/1
casper.forward(); // http://foo.bar/2
casper.run();

Also have a look at back().

log()

Signature: log(String message[, String level, String space])

Logs a message with an optional level in an optional space. Available levels are debug, info, warning and error. A space is a kind of namespace you can set for filtering your logs. By default, Casper logs messages in two distinct spaces: phantom and remote, to distinguish what happens in the PhantomJS environment from the remote one:

casper.start('http://www.google.fr/', function() {
    this.log("I'm logging an error", "error");
});

casper.run();

fill()

Signature: fill(String selector, Object values[, Boolean submit])

Fills the fields of a form with given values and optionally submits it. Fields are referenced by their name attribute.

Example with this sample html form:

<form action="/contact" id="contact-form" enctype="multipart/form-data">
    <input type="text" name="subject"/>
    <textearea name="content"></textearea>
    <input type="radio" name="civility" value="Mr"/> Mr
    <input type="radio" name="civility" value="Mrs"/> Mrs
    <input type="text" name="name"/>
    <input type="email" name="email"/>
    <input type="file" name="attachment"/>
    <input type="checkbox" name="cc"/> Receive a copy
    <input type="submit"/>
</form>

A script to fill and submit this form:

casper.start('http://some.tld/contact.form', function() {
    this.fill('form#contact-form', {
        'subject':    'I am watching you',
        'content':    'So be careful.',
        'civility':   'Mr',
        'name':       'Chuck Norris',
        'email':      'chuck@norris.com',
        'cc':         true,
        'attachment': '/Users/chuck/roundhousekick.doc'
    }, true);
});

casper.then(function() {
    this.evaluateOrDie(function() {
        return /message sent/.test(document.body.innerText);
    }, 'sending message failed');
});

casper.run(function() {
    this.echo('message sent').exit();
});

fillSelectors()

Signature: fillSelectors(String selector, Object values[, Boolean submit])

Fills form fields with given values and optionally submits it. Fields are referenced by CSS3 selectors:

casper.start('http://some.tld/contact.form', function() {
    this.fillSelectors('form#contact-form', {
        'input[name="subject"]':    'I am watching you',
        'input[name="content"]':    'So be careful.',
        'input[name="civility"]':   'Mr',
        'input[name="name"]':       'Chuck Norris',
        'input[name="email"]':      'chuck@norris.com',
        'input[name="cc"]':         true,
        'input[name="attachment"]': '/Users/chuck/roundhousekick.doc'
    }, true);
});

fillXPath()

Signature: fillXPath(String selector, Object values[, Boolean submit])

Fills form fields with given values and optionally submits it. While the form element is always referenced by a CSS3 selector, fields are referenced by XPath selectors:

casper.start('http://some.tld/contact.form', function() {
    this.fillXPath('form#contact-form', {
        '//input[@name="subject"]':    'I am watching you',
        '//input[@name="content"]':    'So be careful.',
        '//input[@name="civility"]':   'Mr',
        '//input[@name="name"]':       'Chuck Norris',
        '//input[@name="email"]':      'chuck@norris.com',
        '//input[@name="cc"]':         true,
    }, true);
});

getCurrentUrl()

Signature: getCurrentUrl()

Retrieves current page URL. Note that the url will be url-decoded:

casper.start('http://www.google.fr/', function() {
    this.echo(this.getCurrentUrl()); // "http://www.google.fr/"
});

casper.run();

getElementAttribute()

Signature: getElementAttribute(String selector, String attribute)

Retrieves the value of an attribute on the first element matching the provided :doc:`selector <../selectors>`:

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

casper.start('http://www.google.fr/', function() {
    require('utils').dump(this.getElementAttribute('div[title="Google"]', 'title')); // "Google"
});

casper.run();

getElementsAttribute()

Signature: getElementsAttribute(String selector, String attribute)

Retrieves the values of an attribute on each element matching the provided :doc:`selector <../selectors>`:

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

casper.start('http://www.google.fr/', function() {
    require('utils').dump(this.getElementsAttribute('div[title="Google"]', 'title')); // "['Google']"
});

casper.run();

getElementBounds()

Signature: getElementBounds(String selector)

Retrieves boundaries for a DOM element matching the provided :doc:`selector <../selectors>`.

It returns an Object with four keys: top, left, width and height, or null if the selector doesn't exist:

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

casper.start('http://www.google.fr/', function() {
    require('utils').dump(this.getElementBounds('div[title="Google"]'));
});

casper.run();

This will output something like:

{
    "height": 95,
    "left": 352,
    "top": 16,
    "width": 275
}

getElementsBounds()

Signature: getElementsBounds(String selector)

Retrieves a list of boundaries for all DOM elements matching the provided :doc:`selector <../selectors>`.

It returns an array of objects with four keys: top, left, width and height (see getElementBounds()).

getElementInfo()

Signature: getElementInfo(String selector)

Retrieves information about the first element matching the provided :doc:`selector <../selectors>`:

casper.start('http://google.fr/', function() {
    require('utils').dump(this.getElementInfo('#hplogo'));
});

Gives something like:

{
    "attributes": {
        "align": "left",
        "dir": "ltr",
        "id": "hplogo",
        "onload": "window.lol&&lol()",
        "style": "height:110px;width:276px;background:url(/images/srpr/logo1w.png) no-repeat",
        "title": "Google"
    },
    "height": 110,
    "html": "<div nowrap=\"nowrap\" style=\"color:#777;font-size:16px;font-weight:bold;position:relative;left:214px;top:70px\">France</div>",
    "nodeName": "div",
    "tag": "<div dir=\"ltr\" title=\"Google\" align=\"left\" id=\"hplogo\" onload=\"window.lol&amp;&amp;lol()\" style=\"height:110px;width:276px;background:url(/images/srpr/logo1w.png) no-repeat\"><div nowrap=\"nowrap\" style=\"color:#777;font-size:16px;font-weight:bold;position:relative;left:214px;top:70px\">France</div></div>",
    "text": "France\n",
    "visible": true,
    "width": 276,
    "x": 62,
    "y": 76
}

getElementsInfo()

Signature: getElementsInfo(String selector)

Retrieves information about all elements matching the provided :doc:`selector <../selectors>`:

casper.start('http://google.fr/', function() {
    require('utils').dump(this.getElementsInfo('#hplogo'));
});

Gives something like:

[
    {
        "attributes": {
            "align": "left",
            "dir": "ltr",
            "id": "hplogo",
            "onload": "window.lol&&lol()",
            "style": "height:110px;width:276px;background:url(/images/srpr/logo1w.png) no-repeat",
            "title": "Google"
        },
        "height": 110,
        "html": "<div nowrap=\"nowrap\" style=\"color:#777;font-size:16px;font-weight:bold;position:relative;left:214px;top:70px\">France</div>",
        "nodeName": "div",
        "tag": "<div dir=\"ltr\" title=\"Google\" align=\"left\" id=\"hplogo\" onload=\"window.lol&amp;&amp;lol()\" style=\"height:110px;width:276px;background:url(/images/srpr/logo1w.png) no-repeat\"><div nowrap=\"nowrap\" style=\"color:#777;font-size:16px;font-weight:bold;position:relative;left:214px;top:70px\">France</div></div>",
        "text": "France\n",
        "visible": true,
        "width": 276,
        "x": 62,
        "y": 76
    }
]

getFormValues()

Signature: getFormValues(String selector)

Retrieves a given form all of its field values:

casper.start('http://www.google.fr/', function() {
    this.fill('form', {q: 'plop'}, false);
    this.echo(this.getFormValues('form').q); // 'plop'
});

casper.run();

getGlobal()

Signature: getGlobal(String name)

Retrieves a global variable value within the remote DOM environment by its name. Basically, getGlobal('foo') will retrieve the value of window.foo from the page:

casper.start('http://www.google.fr/', function() {
    this.echo(this.getGlobal('innerWidth')); // 1024
});

casper.run();

getHTML()

Signature: getHTML([String selector, Boolean outer])

Retrieves HTML code from the current page. By default, it outputs the whole page HTML contents:

casper.start('http://www.google.fr/', function() {
    this.echo(this.getHTML());
});

casper.run();

The getHTML() method can also dump HTML contents matching a given :doc:`selector <../selectors>`; for example with this HTML code:

<html>
    <body>
        <h1 id="foobar">Plop</h1>
    </body>
</html>

You can fetch those contents using:

casper.start('http://www.site.tld/', function() {
    this.echo(this.getHTML('h1#foobar')); // => 'Plop'
});

The outer argument allows to retrieve the outer HTML contents of the matching element:

casper.start('http://www.site.tld/', function() {
    this.echo(this.getHTML('h1#foobar', true)); // => '<h1 id="foobar">Plop</h1>'
});

getPageContent()

Signature: getPageContent()

Retrieves current page contents, dealing with exotic other content types than HTML:

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

casper.start().then(function() {
    this.open('http://search.twitter.com/search.json?q=casperjs', {
        method: 'get',
        headers: {
            'Accept': 'application/json'
        }
    });
});

casper.run(function() {
    require('utils').dump(JSON.parse(this.getPageContent()));
    this.exit();
});

getTitle()

Signature: getTitle()

Retrieves current page title:

casper.start('http://www.google.fr/', function() {
    this.echo(this.getTitle()); // "Google"
});

casper.run();

mouseEvent()

Signature: mouseEvent(String type, String selector)

Triggers a mouse event on the first element found matching the provided selector.

Supported events are mouseup, mousedown, click, mousemove, mouseover and mouseout:

casper.start('http://www.google.fr/', function() {
    this.mouseEvent('click', 'h2 a');
});

casper.run();

open()

Signature: open(String location, Object Settings)

Performs an HTTP request for opening a given location. You can forge GET, POST, PUT, DELETE and HEAD requests.

Example for a standard GET request:

casper.start();

casper.open('http://www.google.com/').then(function() {
    this.echo('GOT it.');
});

casper.run();

Example for a POST request:

casper.start();

casper.open('http://some.testserver.com/post.php', {
    method: 'post',
    data:   {
        'title': 'Plop',
        'body':  'Wow.'
    }
});

casper.then(function() {
    this.echo('POSTED it.');
});

casper.run();

To pass nested parameters arrays:

casper.open('http://some.testserver.com/post.php', {
       method: 'post',
       data: {
            'standard_param': 'foo',
            'nested_param[]': [       // please note the use of square brackets!
                'Something',
                'Something else'
            ]
       }
});

You can also set custom request headers to send when performing an outgoing request, passing the headers option:

casper.open('http://some.testserver.com/post.php', {
    method: 'post',
    data:   {
        'title': 'Plop',
        'body':  'Wow.'
    },
    headers: {
        'Accept-Language': 'fr,fr-fr;q=0.8,en-us;q=0.5,en;q=0.3'
    }
});

reload()

Signature: reload([Function then])

Reloads current page location:

casper.start('http://google.com', function() {
    this.echo("loaded");
    this.reload(function() {
        this.echo("loaded again");
    });
});

casper.run();

repeat()

Signature: repeat(int times, Function then)

Repeats a navigation step a given number of times:

casper.start().repeat(3, function() {
    this.echo("Badger");
});

casper.run();

resourceExists()

Signature: resourceExists(String|Function|RegExp test)

Checks if a resource has been loaded. You can pass either a function, a string or a RegExp instance to perform the test:

casper.start('http://www.google.com/', function() {
    if (this.resourceExists('logo3w.png')) {
        this.echo('Google logo loaded');
    } else {
        this.echo('Google logo not loaded', 'ERROR');
    }
});

casper.run();

run()

Signature: run(fn onComplete[, int time])

Runs the whole suite of steps and optionally executes a callback when they've all been done. Obviously, calling this method is mandatory in order to run the Casper navigation suite.

Casper suite won't run:

casper.start('http://foo.bar/home', function() {
    // ...
});

// hey, it's missing .run() here!

Casper suite will run:

casper.start('http://foo.bar/home', function() {
    // ...
});

casper.run();

Casper.run() also accepts an onComplete callback, which you can consider as a custom final step to perform when all the other steps have been executed. Just don't forget to exit() Casper if you define one!:

casper.start('http://foo.bar/home', function() {
    // ...
});

casper.then(function() {
    // ...
});

casper.run(function() {
    this.echo('So the whole suite ended.');
    this.exit(); // <--- don't forget me!
});

Binding a callback to complete.error will trigger when the onComplete callback fails.

scrollTo()

Signature: scrollTo(Number x, Number y)

Scrolls current document to the coordinates defined by the value of x and y:

casper.start('http://foo.bar/home', function() {
    this.scrollTo(500, 300);
});

scrollToBottom()

Signature: scrollToBottom()

Scrolls current document to its bottom:

casper.start('http://foo.bar/home', function() {
    this.scrollToBottom();
});

sendKeys()

Signature: sendKeys(Selector selector, String keys[, Object options])

Sends native keyboard events to the element matching the provided :doc:`selector <../selectors>`:

casper.then(function() {
    this.sendKeys('form.contact input#name', 'Duke');
    this.sendKeys('form.contact textarea#message', "Damn, I'm looking good.");
    this.click('form.contact input[type="submit"]');
});

The currently supported HTMLElements that can receive keyboard events from sendKeys are <input>, <textarea>, and any HTMLElement with attribute contenteditable="true".

Options

• (Boolean) reset:

  When set to true, this option will first empty the current field value. By default, it's set to false and sendKeys() will just append string to the current field value.

• (Boolean) keepFocus:

  sendKeys() by default will remove the focus on text input fields, which will typically close autocomplete widgets. If you want to maintain focus, use the keepFocus option. For example, if using jQuery-UI, you can click on the first autocomplete suggestion using:

  casper.then(function() {
      this.sendKeys('form.contact input#name', 'action', {keepFocus: true});
      this.click('form.contact ul.ui-autocomplete li.ui-menu-item:first-  child a');
  });
  

• (String) modifiers:

  sendKeys() accepts a modifiers option to support key modifiers. The options is a string representing the composition of modifiers to use, separated by the + character:

  casper.then(function() {
      this.sendKeys('document', 's', {modifiers: 'ctrl+alt+shift'});
  });
  

  Available modifiers are:

  • ctrl
  • alt
  • shift
  • meta
  • keypad

setHttpAuth()

Signature: setHttpAuth(String username, String password)

Sets HTTP_AUTH_USER and HTTP_AUTH_PW values for HTTP based authentication systems:

casper.start();

casper.setHttpAuth('sheldon.cooper', 'b4z1ng4');

casper.thenOpen('http://password-protected.domain.tld/', function() {
    this.echo("I'm in. Bazinga.");
})
casper.run();

Of course you can directly pass the auth string in the url to open:

var url = 'http://sheldon.cooper:b4z1ng4@password-protected.domain.tld/';

casper.start(url, function() {
    this.echo("I'm in. Bazinga.");
})

casper.run();

start()

Signature: start(String url[, Function then])

Configures and starts Casper, then open the provided url and optionally adds the step provided by the then argument:

casper.start('http://google.fr/', function() {
    this.echo("I'm loaded.");
});

casper.run();

Alternatively:

casper.start('http://google.fr/');

casper.then(function() {
    this.echo("I'm loaded.");
});

casper.run();

Or alternatively:

casper.start('http://google.fr/');

casper.then(function() {
    casper.echo("I'm loaded.");
});

casper.run();

Matter of taste!

status()

Signature: status(Boolean asString)

Returns the status of current Casper instance:

casper.start('http://google.fr/', function() {
    this.echo(this.status(true));
});

casper.run();

then()

Signature: then(Function then)

This method is the standard way to add a new navigation step to the stack, by providing a simple function:

casper.start('http://google.fr/');

casper.then(function() {
    this.echo("I'm in your google.");
});

casper.then(function() {
    this.echo('Now, let me write something');
});

casper.then(function() {
    this.echo('Oh well.');
});

casper.run();

You can add as many steps as you need. Note that the current Casper instance automatically binds the this keyword for you within step functions.

To run all the steps you defined, call the run() method, and voila.

casper.start('http://www.google.fr/', function(response) {
    require('utils').dump(response);
});

$ casperjs dump-headers.js
{
    "contentType": "text/html; charset=UTF-8",
    "headers": [
        {
            "name": "Date",
            "value": "Thu, 18 Oct 2012 08:17:29 GMT"
        },
        {
            "name": "Expires",
            "value": "-1"
        },
        // ... lots of other headers
    ],
    "id": 1,
    "redirectURL": null,
    "stage": "end",
    "status": 200,
    "statusText": "OK",
    "time": "2012-10-18T08:17:37.068Z",
    "url": "http://www.google.fr/"
}

casper.start('http://www.google.fr/', function(response) {
    this.echo(response.headers.get('Date'));
});

$ casperjs dump-headers.js
Thu, 18 Oct 2012 08:26:34 GMT

thenBypass()

Signature: thenBypass(Number nb)

Adds a navigation step which will bypass a given number of following steps:

casper.start('http://foo.bar/');
casper.thenBypass(2);
casper.then(function() {
    // This test won't be executed
});
casper.then(function() {
    // Nor this one
});
casper.then(function() {
    // While this one will
});
casper.run();

thenBypassIf()

Signature: thenBypassIf(Mixed condition, Number nb)

Bypass a given number of navigation steps if the provided condition is truthy or is a function that returns a truthy value:

var universe = {
    answer: 42
};
casper.start('http://foo.bar/');
casper.thenBypassIf(function() {
    return universe && universe.answer === 42;
}, 2);
casper.then(function() {
    // This step won't be executed as universe.answer is 42
});
casper.then(function() {
    // Nor this one
});
casper.then(function() {
    // While this one will
});
casper.run();

thenBypassUnless()

Signature: thenBypassUnless(Mixed condition, Number nb)

Opposite of thenBypassIf().

thenClick()

Signature: thenClick(String selector[, Function then])

Adds a new navigation step to click a given selector and optionally add a new navigation step in a single operation:

// Click the first link in the casperJS page
casper.start('http://casperjs.org/').thenClick('a', function() {
    this.echo("I clicked on first link found, the page is now loaded.");
});

casper.run();

This method is basically a convenient a shortcut for chaining a then() and an click() calls.

thenEvaluate()

Signature: thenEvaluate(Function fn[, arg1[, arg2[, …]]])

Adds a new navigation step to perform code evaluation within the current retrieved page DOM:

// Querying for "Chuck Norris" on Google
casper.start('http://google.fr/').thenEvaluate(function(term) {
    document.querySelector('input[name="q"]').setAttribute('value', term);
    document.querySelector('form[name="f"]').submit();
}, 'Chuck Norris');

casper.run();

This method is basically a convenient a shortcut for chaining a then() and an evaluate() calls.

thenOpen()

Signature: thenOpen(String location[, mixed options])

Adds a new navigation step for opening a new location, and optionally add a next step when its loaded:

casper.start('http://google.fr/').then(function() {
    this.echo("I'm in your google.");
});

casper.thenOpen('http://yahoo.fr/', function() {
    this.echo("Now I'm in your yahoo.")
});

casper.run();

You can also specify request settings by passing a setting object (see open()) as the second argument:

casper.start().thenOpen('http://url.to/some/uri', {
    method: "post",
    data: {
        username: 'chuck',
        password: 'n0rr15'
    }
}, function() {
    this.echo("POST request has been sent.")
});

casper.run();

thenOpenAndEvaluate()

Signature: thenOpenAndEvaluate(String location[, Function then[, arg1[, arg2[, …]]])

Basically a shortcut for opening an url and evaluate code against remote DOM environment:

casper.start('http://google.fr/').then(function() {
    this.echo("I'm in your google.");
});

casper.thenOpenAndEvaluate('http://yahoo.fr/', function() {
    var f = document.querySelector('form');
    f.querySelector('input[name=q]').value = 'chuck norris';
    f.submit();
});

casper.run(function() {
    this.debugPage();
    this.exit();
});

toString()

Signature: toString()

Returns a string representation of current Casper instance:

casper.start('http://google.fr/', function() {
    this.echo(this); // [object Casper], currently at http://google.fr/
});

casper.run();

unwait()

Signature: unwait()

Abort all current waiting processes, if any.

userAgent()

Signature: userAgent(String agent)

Sets the User-Agent string to send through headers when performing requests:

casper.start();

casper.userAgent('Mozilla/5.0 (Macintosh; Intel Mac OS X)');

casper.thenOpen('http://google.com/', function() {
    this.echo("I'm a Mac.");
    this.userAgent('Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)');
});

casper.thenOpen('http://google.com/', function() {
    this.echo("I'm a PC.");
});

casper.run();

viewport()

Signature: viewport(Number width, Number height[, Function then])

Changes current viewport size:

casper.viewport(1024, 768);

To be sure page reflowing has occured, you have to use it asynchronously:

casper.viewport(1024, 768).then(function() {
    // new view port is now effective
});

As of 1.1 you can pass a then step function directly to viewport():

casper.viewport(1024, 768, function() {
    // new view port is effective
});

visible()

Signature: visible(String selector)

Checks if the DOM element matching the provided :doc:`selector expression <../selectors>` is visible in remote page:

casper.start('http://google.com/', function() {
    if (this.visible('#hplogo')) {
        this.echo("I can see the logo");
    } else {
        this.echo("I can't see the logo");
    }
});

wait()

Signature: wait(Number timeout[, Function then])

Pause steps suite execution for a given amount of time, and optionally execute a step on done:

casper.start('http://yoursite.tld/', function() {
    this.wait(1000, function() {
        this.echo("I've waited for a second.");
    });
});

casper.run();

You can also write the same thing like this:

casper.start('http://yoursite.tld/');

casper.wait(1000, function() {
    this.echo("I've waited for a second.");
});

casper.run();

waitFor()

Signature: waitFor(Function testFx[, Function then, Function onTimeout, Number timeout, Object details])

Waits until a function returns true to process any next step.

You can also set a callback on timeout using the onTimeout argument, and set the timeout using the timeout one, in milliseconds. The default timeout is set to 5000ms:

casper.start('http://yoursite.tld/');

casper.waitFor(function check() {
    return this.evaluate(function() {
        return document.querySelectorAll('ul.your-list li').length > 2;
    });
}, function then() {
    this.captureSelector('yoursitelist.png', 'ul.your-list');
});

casper.run();

Example using the onTimeout callback:

casper.start('http://yoursite.tld/');

casper.waitFor(function check() {
    return this.evaluate(function() {
        return document.querySelectorAll('ul.your-list li').length > 2;
    });
}, function then() {    // step to execute when check() is ok
    this.captureSelector('yoursitelist.png', 'ul.your-list');
}, function timeout() { // step to execute if check has failed
    this.echo("I can't haz my screenshot.").exit();
});

casper.run();

details is a property bag of various information that will be passed to the waitFor.timeout event, if it is emitted. This can be used for better error messages or to conditionally ignore some timeout events.

waitForAlert()

Signature: waitForAlert(Function then[, Function onTimeout, Number timeout])

Waits until a JavaScript alert is triggered. The step function will be passed the alert message in the response.data property:

casper.waitForAlert(function(response) {
    this.echo("Alert received: " + response.data);
});

waitForPopup()

Signature: waitForPopup(String|RegExp urlPattern[, Function then, Function onTimeout, Number timeout])

Waits for a popup having its url matching the provided pattern to be opened and loaded.

The currently loaded popups are available in the Casper.popups array-like property:

casper.start('http://foo.bar/').then(function() {
    this.test.assertTitle('Main page title');
    this.clickLabel('Open me a popup');
});

// this will wait for the popup to be opened and loaded
casper.waitForPopup(/popup\.html$/, function() {
    this.test.assertEquals(this.popups.length, 1);
});

// this will set the popup DOM as the main active one only for time the
// step closure being executed
casper.withPopup(/popup\.html$/, function() {
    this.test.assertTitle('Popup title');
});

// next step will automatically revert the current page to the initial one
casper.then(function() {
    this.test.assertTitle('Main page title');
});

waitForResource()

Signature: waitForResource(String|Function|RegExp testFx[, Function then, Function onTimeout, Number timeout])

Wait until a resource that matches a resource matching constraints defined by testFx are satisfied to process a next step.

The testFx argument can be either a string, a function or a RegExp instance:

casper.waitForResource("foobar.png", function() {
    this.echo('foobar.png has been loaded.');
});

Using a regexp:

casper.waitForResource(/foo(bar|baz)\.png$/, function() {
    this.echo('foobar.png or foobaz.png has been loaded.');
});

Using a function:

casper.waitForResource(function testResource(resource) {
    return resource.url.indexOf("https") === 0;
}, function onReceived() {
    this.echo('a secure resource has been loaded.');
});

waitForUrl()

Signature: waitForUrl(String|RegExp url[, Function then, Function onTimeout, Number timeout])

Waits for the current page url to match the provided argument (String or RegExp):

casper.start('http://foo/').waitForUrl(/login\.html$/, function() {
    this.echo('redirected to login.html');
});

casper.run();

waitForSelector()

Signature: waitForSelector(String selector[, Function then, Function onTimeout, Number timeout])

Waits until an element matching the provided :doc:`selector expression <../selectors>` exists in remote DOM to process any next step. Uses waitFor():

casper.start('https://twitter.com/#!/n1k0');

casper.waitForSelector('.tweet-row', function() {
    this.captureSelector('twitter.png', 'html');
});

casper.run();

waitWhileSelector()

Signature: waitWhileSelector(String selector[, Function then, Function onTimeout, Number timeout])

Waits until an element matching the provided :doc:`selector expression <../selectors>` does not exist in remote DOM to process a next step. Uses waitFor():

casper.start('http://foo.bar/');

casper.waitWhileSelector('.selector', function() {
    this.echo('.selector is no more!');
});

casper.run();

waitForSelectorTextChange()

Signature: waitForSelectorTextChange(String selectors[, Function then, Function onTimeout, Number timeout])

Waits until the text on an element matching the provided :doc:`selector expression <../selectors>` is changed to a different value before processing the next step. Uses waitFor():

casper.start('http://foo.bar/');

casper.waitForSelectorTextChange('.selector', function() {
    this.echo('The text on .selector has been changed.');
});

casper.run();

waitForText()

Signature: waitForText(String text[, Function then, Function onTimeout, Number timeout])

Waits until the passed text is present in the page contents before processing the immediate next step. Uses waitFor():

casper.start('http://why.univer.se/').waitForText("42", function() {
    this.echo('Found the answer.');
});

casper.run();

waitUntilVisible()

Signature: waitUntilVisible(String selector[, Function then, Function onTimeout, Number timeout])

Waits until an element matching the provided :doc:`selector expression <../selectors>` is visible in the remote DOM to process a next step. Uses waitFor().

waitWhileVisible()

Signature: waitWhileVisible(String selector[, Function then, Function onTimeout, Number timeout])

Waits until an element matching the provided :doc:`selector expression <../selectors>` is no longer visible in remote DOM to process a next step. Uses waitFor().

warn()

Signature: warn(String message)

Logs and prints a warning message to the standard output:

casper.warn("I'm a warning message.");

withFrame()

Signature: withFrame(String|Number frameInfo, Function then)

Switches the main page to the frame having the name or frame index number matching the passed argument, and processes a step.

The page context switch only lasts until the step execution is finished:

casper.start('tests/site/frames.html', function() {
    this.test.assertTitle('FRAMESET TITLE');
});

casper.withFrame('frame1', function() {
    this.test.assertTitle('FRAME TITLE');
});

casper.withFrame(0, function() {
    this.test.assertTitle('FRAME TITLE');
});

casper.then(function() {
    this.test.assertTitle('FRAMESET TITLE');
});

withPopup()

Signature: withPopup(Mixed popupInfo, Function then)

Switches the main page to a popup matching the information passed as argument, and processes a step. The page context switch only lasts until the step execution is finished:

casper.start('http://foo.bar/').then(function() {
    this.test.assertTitle('Main page title');
    this.clickLabel('Open me a popup');
});

// this will wait for the popup to be opened and loaded
casper.waitForPopup(/popup\.html$/, function() {
    this.test.assertEquals(this.popups.length, 1);
});

// this will set the popup DOM as the main active one only for time the
// step closure being executed
casper.withPopup(/popup\.html$/, function() {
    this.test.assertTitle('Popup title');
});

// next step will automatically revert the current page to the initial one
casper.then(function() {
    this.test.assertTitle('Main page title');
});

zoom()

Signature: zoom(Number factor)

Sets the current page zoom factor:

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

casper.start().zoom(2).thenOpen('http://google.com', function() {
    this.capture('big-google.png');
});

casper.run();