Listeners

Listeners help your bot pick up relevant pieces of information from user inputs, even when these have not been explicitly prompted for. You can think of a listener as a fly on the wall, silently listening and registering things.

Flow listener

Listeners are often used to extract entities from user inputs.

Types

When you add a listener to a flow, you can choose to make it listen to all inputs that trigger or pass through the flow or to make it only listen on a particular trigger or transition.

Type Description How to add
Flow listener Listens to all inputs that pass through a flow including inputs that trigger the flow. - Open your flow in edit mode
- Go to the 'Flow' tab on the top left
- Select 'Listeners' from the purple bar on the left hand side.
Trigger / transition listener Is defined in relation to a specific point of a flow; will only kick in for inputs of the trigger or transition where the listener was added. - Open your flow in edit mode
- Select the trigger or transition
- Open the 'Listeners' panel on the right of the 'Flow' window.

Components of a listener

A listener is made up of two parts: a condition and an optional script. The condition determines what patterns should be listened for, e.g. the name of a city. The operation defines what should happen when the condition is met, for example setting a variable, or updating a counter.

Fields of a listener

Sometimes you can extract the information you want in the condition itself. In that case, you don't need to specify a script. In the example below the listener extracts the destination mentioned in the user input. More on how to extract data from inputs here.

Listener with a condition

If you need additional programmatic logic, for example to further process what you have extracted, you can add it to the script field:

Listener with an operation

Use cases

  • Flow listeners are defined for a flow and listen to all inputs that trigger or pass through a flow. They are generally used when your bot should pick up certain pieces of information wherever they are mentioned in the flow dialog. Slot filling flows typically make use of flow listeners.
  • Trigger/transition listeners are attached to a specific trigger or transition of a flow. A trigger/transition listener can be the best solution when you need to pick up something that can be interpreted differently depending on where you are in the flow. For example, if a flow should pick up two dates from a user (like an arrival and departure date for a holiday), you can add a listener to the transition where the user is asked for the arrival date and another listener to the transition for the departure date.

    If you find yourself creating the same listener on multiple triggers or transitions, you might want to check if you can use flow listener instead.

Global listener

In addition to flow listeners Teneo also allows you to create global listeners that listen to any input, independent of the flow.

Global listeners, just like flow listeners, help your bot pick up relevant pieces of information from user inputs, even when these things have not been explicitly prompted for. You can think of a listener as a fly on the wall, silently listening and registering things. However, global listeners listen to any input in a conversation, whereas flow listeners only listen to inputs that trigger or pass through a particular flow.

When to use a global listener

It can be very tempting to use a global listener any time you want to pick something up from an input. For example, you could create a global listener that stores the name of a user in a global variable 'userName' whenever a name is encountered in an input. However, this is generally not a good practice. Because the global listener operates on each input, it might accidentally overwrite 'userName' with any name, like the name of the user's sister for example. In general it is best to use a flow listener for the flow where you specifically anticipate to receive a particular detail and only use global listeners to listen for things that transcend flows.

Components

Global listeners are made up of the same parts as flow listeners: a condition and an operation. The condition determines what patterns should be listened for, e.g. a postive sentiment. The operation defines what should happen when the condition is met, for example updating a counter or adding an annotation. An example of a global listener that counts the number inputs in a conversation that express a positive sentiment could look like this:

Global listener example

You manage global listeners in the Globals area of your solution:

Manage global listeners

Pre or post matching

There are two types of global listeners, pre matching listeners and post matching listeners.

  • Pre listeners - Pre matching listeners listen to inputs before Teneo tries to match the input to a trigger or transition. This makes them best suited when you want to do things that are important during matching. For example, you can use them to add annotations that can then influence if a particular trigger or transitions should match. For example, a pre-listener can annotate a postal code in an input and a language condition might say 'you should only match if a postal code is present in the input'. Because the annotation is added before Teneo tries to match the language condtions, the annotation will be taken into account.
  • Post listeners - Post matching listeners act on inputs directly after Teneo found a matching trigger or a transition that waited for a new input. You can't use these to do things that are important during the matching process, because by the time the post listeners are executed, the matching process is already completed. You can use them to for example check if the currently triggered flow was stored in a particular folder, like the "Summer Campaign" folder. If true, the listener would then perform the task specified in the listener's operation.

You can find more details about the order in which Teneo executes listeners (and other tasks) in the Input processing path reference.

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