PHP SDK

Introduction

Welcome to the developer documentation for the Kameleoon PHP SDK! Our SDK gives you the possibility of running experiments and activating feature flags on your back-end PHP server. Integrating our SDK into your web-application is easy, and its footprint (in terms of memory and network usage) is low.

You can refer to the SDK reference to check out all possible features of the SDK. Also make sure you check out our Getting started tutorial which we have prepared to walk you through the installation and implementation.

Latest version of the PHP SDK: 2.0.4.

Getting started

This guide is designed to help you integrate our SDK in a few minutes and start running experiments in your PHP applications. This tutorial will explain the setup of a simple A/B test to change the number of recommended products based on different variations.

Creating an experiment

First, you must create an experiment in the Kameleoon back-office so that our platform is aware of the new A/B test you're planning to implement on your side. Make sure that server-side type is chosen as shown below:

Upon successful creation of the experiment, you will need to get its ID to use in the SDK as an argument to the triggerExperiment() method.

Installing the SDK

You should install our SDK by downloading it from this link. Once uncompressed, you will see two directories: kameleoon/ and job/.

Installing the PHP client (Composer package)

The kameleoon/ directory corresponds to the PHP package itself, which should be used with the Composer dependency manager. Install this directory in your composer hierarchy (so you should have vendor/kameleoon/client/src). Then edit composer.json and add a Kameleoon entry:

"autoload": {
    "psr-4": {
        "Kameleoon\\": "vendor/kameleoon/client/src"
    }
}

Finally, execute the following command to regenerate the autoloader:

composer dump-autoload -o

Installing the cron job

The job/ directory corresponds to a job that must be executed via a standard job scheduler (like cron). We suggest to install the script itself to /usr/local/opt/kameleoon/kameleoon-client-php-process-queries.sh and to use our default supplied crontab entry. But you can install it in another location and modify the crontab entry accordingly.

Additional configuration

You can customize the behavior of the PHP SDK via a configuration file. We provide a sample configuration file named client-php.json.sample in the SDK archive. We suggest to install this file to the default path of /etc/kameleoon/client-php.json. With the current version of the PHP SDK, 6 keys are available:

• client_id: a client_id is required for authentication to the Kameleoon service.
• client_secret: a client_secret is required for authentication to the Kameleoon service.
• kameleoon_work_dir: this specifies a working directory for the PHP client (who will create files on this directory). It needs to be writable by the PHP user. If not specified, by default the directory will be /tmp/kameleoon/client-php/.
• actions_configuration_refresh_interval: this specifies the refresh interval, in minutes, of the configuration for experiments and personalizations (the active experiments and personalizations are fetched from the Kameleoon servers). It means that once you launch an experiment, pause it, or stop it the changes can take (at most) the duration of this interval to be propagated in production to your servers. If not specified, the default interval is 60 minutes.
• cookie_options: this is a map containing configuration options for the kameleoonVisitorCode cookie set by the obtainVisitorCode() method. Following keys are available:
  • domain: this controls the domain of the cookie and should be set to your top-level domain (very important). This value can be overriden by an argument of the obtainVisitorCode() method.
  • secure: this controls the secure cookie attribute. Default value is false.
  • http_only: this controls the httponly cookie attribute. Default value is false.
  • samesite: this controls the samesite cookie attribute. Default value is None.
• debug_mode: this parameter sends additional information to our tracking servers to help analyze difficult issues. It should usually be off (false), but activating it (true) has no impact on the SDK performance.

Initializing the Kameleoon client

<?php
    require "vendor/autoload.php";

    $kameleoonClient = Kameleoon\KameleoonClientFactory::create("a8st4f59bj", false);

    $kameleoonClient = Kameleoon\KameleoonClientFactory::create("a8st4f59bj", false, "/etc/kameleoon/client-php.json");

    $kameleoonClient = Kameleoon\KameleoonClientFactory::create("a8st4f59bj", true);
?>

After installing the SDK into your application, configuring the correct credentials (in /etc/kameleoon/client-php.json) and setting up a server-side experiment on Kameleoon's back-office, the next step is to create the Kameleoon client in your application code.

The code on the right gives a clear example. A KameleoonClient is a singleton object that acts as a bridge between your application and the Kameleoon platform. It includes all the methods and properties you will need to run an experiment. Note that the SDK takes its settings from a configuration file. By default, the path /etc/kameleoon/client-php.json will be used, but you can use a different path for the configuration file by providing an optional third argument to the KameleoonClientFactory::create() method.

Triggering an experiment

<?php
    require "vendor/autoload.php";

    $kameleoonClient = Kameleoon\KameleoonClientFactory::create("a8st4f59bj", false, "/etc/kameleoon/client-php.json");

    $visitorCode = $kameleoonClient->obtainVisitorCode("example.com");
    $recommendedProductsNumber;

    try
    {
        $variationId;
        try {
            $variationID = $kameleoonClient->triggerExperiment($visitorCode, 75253);
        }
        catch (Kameleoon\Exception\NotTargeted $e)
        {
           // The user did not trigger the experiment, as the associated targeting segment conditions were not fulfilled. He should see the reference variation
            $variationID = 0;
        }
        catch (Kameleoon\Exception\NotActivated $e) {
            // The user triggered the experiment, but did not activate it. Usually, this happens because the user has been associated with excluded traffic
            variationID = 0;
        }
        catch (Kameleoon\Exception\ExperimentConfigurationNotFound $e) {
            // The user will not be counted into the experiment, but should see the reference variation
            variationID = 0;
        }

        if ($variationID == 0)
        {
            //We are changing number of recommended products for this variation to 5
            $recommendedProductsNumber = 5;
        }
        else if ($variationID == 148382)
        {
            //We are changing number of recommended products for this variation to 10
            $recommendedProductsNumber = 10;
        }
        else if ($variationID == 187791)
        {
            //We are changing number of recommended products for this variation to 8
            $recommendedProductsNumber = 8;
        }

        // Here you should have code to generate the HTML page back to the client, where recommendedProductsNumber will be used
        echo $recommendedProductsNumber;
    }
    catch (Exception $e)
    {
        echo "Exception: ",  $e->getMessage(), "\n";
    }
?>

Running an A/B experiment on your PHP application means bucketing your visitors into several groups (one per variation). The SDK takes care of this bucketing (and the associated reporting) automatically.

Triggering an experiment by calling the triggerExperiment() method will register a random variation for a given visitorCode. If this visitorCode is already associated with a variation (most likely a returning visitor that has already been exposed to the experiment previously), then it will return the previous variation associated with a given experiment.

Implementing variation code

<?php
$recommendedProductsNumber;
if ($variationID == 0)
{
    //We are changing number of recommended products for this variation to 5
    $recommendedProductsNumber = 5;
}
else if ($variationID == 148382)
{
    //We are changing number of recommended products for this variation to 10
    $recommendedProductsNumber = 10;
}
else if ($variationID == 187791)
{
    //We are changing number of recommended products for this variation to 8
    $recommendedProductsNumber = 8;
}
?>

To execute different code paths depending on the variation assigned to the visitor, you will need the list of all the experiment's variation IDs. You can find these variation IDs (as well as the experiment ID) by opening the experiment in hte back-office interface.

Once you have the IDs of the different variations, you can implement a different action for each variation, and one of the code paths will be executed, based on the associated variationID for the current visitor. Generally, this can be done using a simple if / else or switch mechanism. In our example, we just change the number of recommended products with two different variations.

Tracking conversion

<?php
    require "vendor/autoload.php";

    $kameleoonClient = Kameleoon\KameleoonClientFactory::create("a8st4f59bj", false, "/etc/kameleoon/client-php.json");
    $visitorCode = $kameleoonClient->obtainVisitorCode("example.com");
    $recommendedProductsNumber;

    $goalID = 83023;
    $kameleoonClient->trackConversion($visitorCode, $goalID);
?>

After you are done with triggering an experiment, the next step is usually to start tracking conversions. This is done to measure performance characteristics according to the goals that make sense for your business.

For this purpose, use the trackConversion() method of the SDK as shown in the example. You need to pass the visitorCode and goalID parameters so we can correctly track conversion for this particular visitor.

Obtaining results

Once your implementation is in place on the server side (experiment triggering, variations handling, and conversion tracking), it is time to launch the experiment on the Kameleoon platform. You do this in the same way as for a front-end test. Basic operations such as starting, pausing and stopping the experiment work exactly the same way.

After the experiment is launched, the first results will be available on our standard results page in the back-office after a duration of 30 minutes. This is because (as is the case with front-end testing) visits are considered over after 30 minutes of inactivity. Inactivity in this context means the absence of calls sent to the Kameleoon back-end servers (such calls are made via triggerExperiment(), trackConversion() or flush() methods).

Reference

This is a full reference documentation of the PHP SDK.

If this is your first time working with the PHP SDK, we strongly recommend you go over our Getting started tutorial to integrate the SDK and start experimenting in a few minutes.

Kameleoon\KameleoonClientFactory

create

<?php
    require "vendor/autoload.php";

    $kameleoonClient = Kameleoon\KameleoonClientFactory::create("a8st4f59bj");
?>

The starting point for using the SDK is the initialization step. All interaction with the SDK is done through an object named KameleoonClient, therefore you need to create this object.

Arguments

Return value

Exceptions Thrown

Kameleoon\KameleoonClient

obtainVisitorCode

<?php
    require "vendor/autoload.php";

    $visitorCode = $kameleoonClient->obtainVisitorCode(); // The cookie's domain must be provided in the configuration file if no argument is given
    $visitorCode = $kameleoonClient->obtainVisitorCode("example.com");
    $visitorCode = $kameleoonClient->obtainVisitorCode("example.co.uk", $userID);
?>

This helper method should be called to obtain the Kameleoon visitorCode for the current visitor. This is especially important when using Kameleoon in a mixed front-end and back-end environment, where user identification consistency must be guaranteed. The implementation logic is described here:

1. First we check if a kameleoonVisitorCode cookie or query parameter associated with the current HTTP request can be found. If so, we will use this as the visitor identifier.

2. If no cookie / parameter is found in the current request, we either randomly generate a new identifier, or use the defaultVisitorCode argument as identifier if it is passed. This allows our customers to use their own identifiers as visitor codes, should they wish to. This can have the added benefit of matching Kameleoon visitors with their own users without any additional look-ups in a matching table.

3. In any case, the server-side (via HTTP header) kameleoonVisitorCode cookie is set with the value. Then this identifier value is finally returned by the method.

For more information, refer to this article.

Arguments

Return value

Exceptions Thrown

triggerExperiment

<?php
    require "vendor/autoload.php";

    $kameleoonClient = Kameleoon\KameleoonClientFactory::create("a8st4f59bj");
    $visitorCode = $kameleoonClient->obtainVisitorCode("example.com");
    $experimentID = 75253;
    $variationID;

    try {
        $variationID = $kameleoonClient->triggerExperiment($visitorCode, $experimentID);
    }
    catch (Kameleoon\Exception\NotTargeted $e) {
        // The user did not trigger the experiment, as the associated targeting segment conditions were not fulfilled. He should see the reference variation
        variationID = 0;
    }
    catch (Kameleoon\Exception\NotActivated $e) {
        // The user triggered the experiment, but did not activate it. Usually, this happens because the user has been associated with excluded traffic
        variationID = 0;
    }
    catch (Kameleoon\Exception\ExperimentConfigurationNotFound $e) {
        // This experiment was not found in the SDK configuration. The user will not be counted into the experiment, but should see the reference variation
        variationID = 0;
    }
?>

To trigger an experiment call the triggerExperiment() method of our SDK.

This method takes visitorCode and experimentID as mandatory arguments to register a variation for a given user.

If such a user has never been associated with any variation, the SDK returns a randomly selected variation. If a user with a given visitorCode is already registered with a variation, it will detect the previously registered variation and return the variationID.

You have to make sure that proper error handling is set up in your code as shown in the example to the right to catch potential exceptions.

Arguments

Return value

Exceptions Thrown

activateFeature

<?php
    require "vendor/autoload.php";

    $visitorCode = $kameleoonClient->obtainVisitorCode("example.com");
    $featureKey = "new_checkout";
    $hasNewCheckout = false;

    try {
        $hasNewCheckout = $kameleoonClient->activateFeature($visitorCode, $featureKey);
    }
    catch (Kameleoon\Exception\NotTargeted $e) {
        // The user did not trigger the feature, as the associated targeting segment conditions were not fulfilled. The feature should be considered inactive
        $hasNewCheckout = false;
    }
    catch (Kameleoon\Exception\FeatureConfigurationNotFound $e) {
        // Feature toggle not yet activated on Kameleoon's side - we consider the feature inactive
        $hasNewCheckout = false;
    }
    catch (Exception $e) {
        // This is generic Exception handler which will handle all exceptions.
        echo "Exception: ",  $e->getMessage(), "\n";
    }
    if ($hasNewCheckout)
    {
        // Implement new checkout code here
    }
?>

To activate a feature toggle, call the activateFeature() method of our SDK.

This method takes a visitorCode and featureKey (or featureID) as mandatory arguments to check if the specified feature will be active for a given user.

If such a user has never been associated with this feature flag, the SDK returns a boolean value randomly (true if the user should have this feature or false if not). If a user with a given visitorCode is already registered with this feature flag, it will detect the previous featureFlag value.

You have to make sure that proper error handling is set up in your code as shown in the example to the right to catch potential exceptions.

Arguments

Return value

Exceptions Thrown

obtainVariationAssociatedData

$visitorCode = $kameleoonClient->obtainVisitorCode("example.com");
$experimentID = 75253;

try {
    $variationID = $kameleoonClient->triggerExperiment(visitorCode, experimentID);
    $jsonObject = $kameleoonClient->obtainVariationAssociatedData(variationID);
    $firstName = $jsonObject->firstName;
}
catch (Kameleoon\Exception\VariationConfigurationNotFound $e) {
    // The variation is not yet activated on Kameleoon's side, ie the associated experiment is not online
}
catch (Exception $e) {
    // This is generic Exception handler which will handle all exceptions.
    echo "Exception: ",  $e->getMessage(), "\n";
}

To retrieve JSON data associated with a variation, call the obtainVariationAssociatedData() method of our SDK. The JSON data usually represents some metadata of the variation, and can be configured on our web application interface or via our Automation API.

This method takes the variationID as a parameter and will return the data as a Object instance. It will throw an exception (Kameleoon\Exception\VariationConfigurationNotFound) if the variation ID is wrong or corresponds to an experiment that is not yet online.

Arguments

Return value

Exceptions Thrown

obtainFeatureVariable

$featureKey = "myFeature";
$variableKey = "myVariable";
$data;

try {
    $data = $kameleoonClient->obtainFeatureVariable($featureKey, $variableKey);
}
catch (Kameleoon\Exception\FeatureConfigurationNotFound $e) {
    // The feature is not yet activated on Kameleoon's side
}
catch (Exception $e) {
    // This is generic Exception handler which will handle all exceptions.
    echo "Exception: ",  $e->getMessage(), "\n";
}

To retrieve a feature variable, call the obtainFeatureVariable() method of our SDK. A feature variable can be changed easily via our web application.

This method takes two input parameters: featureKey and variableKey. It will return the data as a Object instance. Usually it should be casted to the expected type (the one defined on the web interface). It will throw an exception (Kameleoon\Exception\FeatureConfigurationNotFound) if the requested feature has not been found in the internal configuration of the SDK.

Arguments

Return value

Exceptions Thrown

trackConversion

<?php
    require "vendor/autoload.php";

    $kameleoonClient = Kameleoon\KameleoonClientFactory::create("a8st4f59bj", false, "/etc/kameleoon/client-php.json");
    $visitorCode = $kameleoonClient->obtainVisitorCode("example.com");
    $goalID = 83023;

    $kameleoonClient->addData($visitorCode, new Kameleoon\Data\Browser(Kameleoon\Data\Browser::$browsers["CHROME"]));
    $kameleoonClient->addData(
        $visitorCode,
        new Kameleoon\Data\PageView("https://url.com", "title", 3),
        new Kameleoon\Data\Interest(2)
    );
    $kameleoonClient->addData($visitorCode, new Kameleoon\Data\Conversion(32, 10, false));

    $kameleoonClient->trackConversion($visitorCode, $goalID);
?>

To track conversion, use the trackConversion() method. This method requires visitorCode and goalID to track conversion on this particular goal. In addition, this method also accepts revenue as a third optional argument to track revenue. The visitorCode usually is identical to the one that was used when triggering the experiment.

The trackConversion() method doesn't return any value. This method is non-blocking as the server call is made asynchronously.

Arguments

addData

<?php
    $kameleoonClient->addData($visitorCode, new Kameleoon\Data\Browser(Kameleoon\Data\Browser::$browsers["CHROME"]));
    $kameleoonClient->addData(
        $visitorCode,
        new Kameleoon\Data\PageView("https://url.com", "title", 3),
        new Kameleoon\Data\Interest(0)
    );
    $kameleoonClient->addData($visitorCode, new Kameleoon\Data\Conversion(32, 10, false));
?>

To associate various data with the current user, we can use the addData() method. This method requires the visitorCode as a first parameter, and then accepts several additional parameters. Those additional parameters represent the various Data Types allowed in Kameleoon.

Note that the addData() method doesn't return any value and doesn't interact with the Kameleoon back-end servers by itself. Instead, the declared data is saved for future sending via the flush() method described in the next paragraph. This reduces the number of server calls made, as data is usually grouped into a single server call triggered by the execution of flush().

Arguments

flush

<?php
    $visitorCode = $kameleoonClient->obtainVisitorCode("example.com");

    $kameleoonClient->addData($visitorCode, new Kameleoon\Data\Browser(Kameleoon\Data\Browser::$browsers["CHROME"]));
    $kameleoonClient->addData(
        $visitorCode,
        new Kameleoon\Data\PageView("https://url.com", "title", 3),
        new Kameleoon\Data\Interest(0)
    );
    $kameleoonClient->addData($visitorCode, new Kameleoon\Data\Conversion(32, 10, false));

    $kameleoonClient->flush($visitorCode);
?>

Data associated with the current user via addData() method is not sent immediately to the server. It is stored and accumulated until it is sent automatically by the triggerExperiment() or trackConversion() methods, or manually by the flush() method. This allows the developer to control exactly when the data is flushed to our servers. For instance, if you call the addData() method a dozen times, it would be a waste of ressources to send data to the server after each addData() invocation. Just call flush() once at the end.

The flush() method doesn't return any value. This method is non-blocking as the server call is made asynchronously.

Arguments

Kameleoon\Data

Browser

<?php
    $kameleoonClient->addData($visitorCode, new Kameleoon\Data\Browser(Kameleoon\Data\Browser::$browsers["CHROME"]));
?>

PageView

<?php
    $kameleoonClient->addData(
        $visitorCode,
        new Kameleoon\Data\PageView("https://url.com", "title", 3)
    );
?>

Conversion Data Type

<?php
    $kameleoonClient->addData($visitorCode, new Kameleoon\Data\Conversion(32, 10, false));
?>

CustomData

<?php
    $kameleoonClient->addData($visitorCode, new Kameleoon\Data\CustomData(1, "some custom value"));
?>

Interest

<?php
    $kameleoonClient->addData($visitorCode, new Kameleoon\Data\Interest(0));
?>