complex JavaScript interactions are hard to test. That's why you may need to use waiters, actions with *wait* prefix.

They can be used to specify what event you expect to occur on a page, before continuing the test.

the test will fail. There are other `wait` methods you may use, like [waitForText](http://codeception.com/docs/modules/WebDriver#waitForText),

[waitForElementVisible](http://codeception.com/docs/modules/WebDriver#waitForElementVisible) and others.

If you don't know what exact element you need to wait for, you can simply pause execution with using `$I->wait()`

{% highlight php %}

$I->wait(3); // wait for 3 secs

{% endhighlight %}

#### Wait and Act

To combine `waitForElement` with actions inside that element you can use [performOn](http://codeception.com/docs/modules/WebDriver#performOn) method.

Let's see how can you perform some actions inside an HTML popup:

{% highlight php %}

$I->performOn('.confirm', \Codeception\Util\ActionSequence::build()

->see('Warning')

->see('Are you sure you want to delete this?')

->click('Yes')

);

{% endhighlight %}

Alternatively, this can be executed using callback, in this case WebDriver module instance is passed as argument

{% highlight php %}

$I->performOn('.confirm', function(\Codeception\Module\WebDriver $I) {

$I->see('Warning');

$I->see('Are you sure you want to delete this?');

$I->click('Yes');

});

{% endhighlight %}

For more options see [`performOn` reference]([performOn](http://codeception.com/docs/modules/WebDriver#performOn) ).

Binds a queue to an exchange

This is an alias of method `queue_bind` of `PhpAmqpLib\Channel\AMQPChannel`.

{% highlight php %}

$I->bindQueueToExchange(

'nameOfMyQueueToBind', // name of the queue

'transactionTracking.transaction', // exchange name to bind to

'your.routing.key' // Optionally, provide a binding key

//.. see the original method for more options

)

{% endhighlight %}

#### declareExchange

Declares an exchange

This is an alias of method `exchange_declare` of `PhpAmqpLib\Channel\AMQPChannel`.

{% highlight php %}

$I->declareExchange(

'nameOfMyExchange', // exchange name

'topic' // exchange type

//.. see the original method for more options

)

{% endhighlight %}

#### declareQueue

Declares a queue

This is an alias of method `queue_declare` of `PhpAmqpLib\Channel\AMQPChannel`.

{% highlight php %}

$I->declareQueue(

'nameOfMyQueue', // exchange name

//.. see the original method for more options

)

{% endhighlight %}

#### performOn

Waits for element and runs a sequence of actions inside its context.

Actions can be defined with array, callback, or `Codeception\Util\ActionSequence` instance.

Actions as array are recommended for simple to combine "waitForElement" with assertions;

`waitForElement($el)` and `see('text', $el)` can be simplified to:

{% highlight php %}

$I->performOn($el, ['see' => 'text']);

{% endhighlight %}

List of actions can be pragmatically build using `Codeception\Util\ActionSequence`:

{% highlight php %}

$I->performOn('.model', ActionSequence::build()

->see('Warning')

->see('Are you sure you want to delete this?')

->click('Yes')

);

{% endhighlight %}

Actions executed from array or ActionSequence will print debug output for actions, and adds an action name to

exception on failure.

Whenever you need to define more actions a callback can be used. A WebDriver module is passed for argument:

{% highlight php %}

$I->performOn('.rememberMe', function (WebDriver $I) {

$I->see('Remember me next time');

$I->seeElement('#LoginForm_rememberMe');

$I->dontSee('Login');

});

{% endhighlight %}

In 3rd argument you can set number a seconds to wait for element to appear

* `param` $element

* `param` $actions

* `param int` $timeout

* `[Part]` json

* `[Part]` xml

Checks if the hash of a binary response is not the same as provided.

{% highlight php %}

$I->dontSeeBinaryResponseEquals("8c90748342f19b195b9c6b4eff742ded");

?>

{% endhighlight %}

Opposite to `seeBinaryResponseEquals`

* `param` $hash the hashed data response expected

* `param` $algo the hash algorithm to use. Default md5.

* `[Part]` json

* `[Part]` xml

Checks if the hash of a binary response is exactly the same as provided.

Parameter can be passed as any hash string supported by hash(), with an

optional second parameter to specify the hash type, which defaults to md5.

Example: Using md5 hash key

{% highlight php %}

$I->seeBinaryResponseEquals("8c90748342f19b195b9c6b4eff742ded");

?>

{% endhighlight %}

Example: Using md5 for a file contents

{% highlight php %}

$I->seeBinaryResponseEquals(md5($fileData));

?>

{% endhighlight %}

Example: Using sha256 hsah

{% highlight php %}

$I->seeBinaryResponseEquals(hash("sha256", base64_decode($fileData)), 'sha256');

?>

{% endhighlight %}

* `param` $hash the hashed data response expected

* `param` $algo the hash algorithm to use. Default md5.

* `[Part]` json

* `[Part]` xml