Data Element Types

A data element type library module has one goal: retrieve a piece of data. How this piece of data is retrieved is up to you. Perhaps you would like to allow Launch users to retrieve a piece of data from the XDM? Or from their custom data layer?

The module exports should look like this:

module.exports = (context) => { ... };

Let’s assume that we would like to allow users to retrieve a piece of data from the custom data layer. Our module may look like this:

module.exports = (context) => {
  const productName = context.arc.event.data.productName;
  return productName;
}

Now what if we wanted to make the data returned from the data layer configurable by the Launch user? In our view we would allow the user to input a key name and then save the name to the settings object. The object might look something like this:

{
  keyName: "campaignId"
}

In order to operate on the user-defined local storage item name, our module would need to change to this:

module.exports = (context) => {
  const data = context.arc.event.data;
  return data[keyName];
}

Default Value Support

Be aware that users have the option to configure a default value for any data element. If your data element library module returns a value of undefined or null, it will be automatically replaced by the default value the user has configured for the data element.

Library Module Context

All data element modules have access to a context variable that is provided when the module is called. You can learn more here.