How to use list and composite entities in Dialogflow ES

I will explain how to use list and composite entities in the article.

Suppose you sell three products - KitKat, Snickers and Twix. The user can place an order where they can ask for any quantity of each type. E.g. “I would like 3 Snickers, 1 Twix and 2 Kitkat”

Is there a way to get this input in Dialogflow?

The list and composite entities can help.

Declare the chocolate entity.

Next use the chocolate entity to create an item entity. As you can see the item entity is a “composite” entity, meaning it combines two entities - a number (for quantity) and the chocolate entity

In the Default Welcome intent, add await_order as the output context

Add another intent called provides.order

Notice the following:

when you provide the training phrase, Dialogflow ES annotates multiple “item” entities and then also suggests that the item entity (in the parameters table) is a “List”

You can invoke the values of these entities using the format $item[0] and $item[1] etc (based on the maximum number of entities you think the user might provide).

Let us test this bot

As you can see, when we invoke the values inside the text response, there isn’t really any guarantee that Dialogflow ES will use a specific order. That makes it tricky to use this in the Text Response block.

However, you will see that the webhook does get the correct “parsed” item values. You can check this by looking at the Raw Interaction Log inside your History tab.