Managing a variation's allocation according to specific criteria

Kameleoon randomly allocates a variation to a visitor by default. The statistical paper explains the assignment algorithm logic in the “Kameleoon’s assignation algorithm” section. The default function follows:

function (experiment)
{
  var registeredVariationId;
  var deviationRandom = experiment.obtainVariationAssignmentRandomNumber();
  var total = 0.0;
  for (var i = 0, l = experiment.variations.length; i < l; ++i)
  {
      total += experiment.variations[i].deviation;
      if (deviationRandom <= total)
      {
          registeredVariationId = experiment.variations[i].id;
          break;
      }
  }
  return registeredVariationId ? registeredVariationId : "none";
}

Overload this function to change how Kameleoon selects and displays variations. For example, selecting a variation based on a JavaScript variable is often beneficial:

function(experiment)
{
 if(experiment.id == "ID TEST"){ //code for the experiment you would like a specific behavior. It has to be adapted to your use case
 if(typeof versionTest != "undefined") { //versionTest variable has to be available before loading Kameleoon. Otherwise it will not work.
 if(versionTest == 1)
 return 81103; //ID of the variation 1
 else if(versionTest == 2)
 return 81104; //ID of the variation 2
 else if(versionTest == 3)
 return 81105; //ID of the variation 3
 else if(versionTest == 4) //ID of the variation 4
 return 81106;
 }
 }
 else{ //default behavior is applied for all other experiments
 var registeredVariationId;
 var deviationRandom = experiment.obtainVariationAssignmentRandomNumber();
 var total = 0.0;
 for (var i = 0, l = experiment.variations.length; i < l; ++i)
 {
 total += experiment.variations[i].deviation;
 if (deviationRandom <= total)
 {
 registeredVariationId = experiment.variations[i].id;
 break;
 }
 }
 return registeredVariationId ? registeredVariationId : "none";
 }
}

Add the custom code to the account:

Use the left menu to go to Admin > Projects.
Click Edit on your project’s row.
Click the Scripts tab.

The Scripts tab with the Global custom script and Variation selection script editors

Next to Variation selection script, click Edit, then add the script.

APIs