Slot Example Rasa
The Domain
defines the universe in which your bot operates.It specifies the intents
, entities
, slots
, and actions
your bot should know about. Optionally, it can also include templates
for the things your bot can say.
- By default, Rasa Open Source fills a slot with an entity that has the same name. So if you’ve defined a name slot in your domain file, and you also have a name entity defined in your domain and training data, when the NLU model extracts the name entity, it’ll be saved to the name slot automatically.
- This is also called slot filling. If you need to collect multiple pieces of information in a row, we recommended that you create a FormAction. This is a single action which contains the logic to loop over the required slots and ask the user for this information. There is a full example using forms in the examples/formbot directory of Rasa Core.
- Rasa.db file is a database where all the conversation with your bot Is stored. Domain.yml file: In which you are storing all the actions, intents, entities, templates and slots.
- In the example above, an entity date uniquely sets the slot arrivaldate, an entity city with a role from uniquely sets the slot departurecity and an entity city with a role to uniquely sets the slot arrivalcity, therefore they can be used to fit corresponding slots even if these slots were not requested.
From rasasdk.events import SlotSet. Then in you run method, you can set your value in relevant slot. Imagine you slot name for humidity is weatherhumidity. Then imagine your humidity value from the API is extracted for a variable called humidity. Then in your custom action run method, simply set the slot value with below line.
As an example, the DefaultDomain
has the following yaml definition:
What does this mean?
Your NLU model will define the intents
and entities
that youneed to include in the domain.
slots
are the things you want to keep track of during a conversation,see Using Slots . A categorical slot called risk_level
would bedefined like this:
Here is the full list of slot types defined byRasa Core, along with syntax for including them in your domain file.
actions
are the things your bot can actually do.For example, an action
can:
- respond to a user
- make an external API call
- query a database
see Actions
For a more complete example domain, check the Quickstart.
Custom Actions and Slots¶
To reference slots in your domain, you need to reference them bytheir module path. To reference custom actions, use their name.For example, if you have a module called my_actions
containinga class MyAwesomeAction
, and module my_slots
containingMyAwesomeSlot
, you would add these lines to the domain file:
The name
function of MyAwesomeAction
needs to returnmy_custom_action
in this example (for more details,see Actions).
Utterance templates¶
Utterance templates are messages the bot will send back to the user. There aretwo ways to use these templates:
if the name of the template starts with
utter_
, the utterance candirectly be used like an action. You would add the utterance templateto the domainAfterwards, you can use the template as if it were an action in thestories:
When
utter_greet
is run as an action, it will send the message fromthe template back to the user.You can use the templates to generate response messages from yourcustom actions using the dispatcher:
dispatcher.utter_template('utter_greet')
.This allows you to separate the logic of generatingthe messages from the actual copy. In you custom action code, you cansend a message based on the template like this:
Images and Buttons¶
Templates defined in a domains yaml file can contain images andbuttons as well:
Note
Please keep in mind that it is up to the implementation of the outputchannel on how to display the defined buttons. E.g. the cmdlineinterface can not display buttons or images, but tries to mimic them inthe command line.
Variables¶
You can also use variables in your templates to insert informationcollected during the dialogue. You can either do that in your custom pythoncode or by using the automatic slot filling mechanism. E.g if yougot a template like this:
Rasa will automatically fill that variable with a value found in a slot calledname
.
In custom code, you can retrieve a template by using:
If the template contains variables denoted with {my_variable}
you can supply values for the fields by passing them as key wordarguments to utter_template
:
Variations¶
If you want to randomly vary the response sent to the user, you can listmultiple responses and Rasa will randomly pick one of them, e.g.:
Ignoring entities for certain intents¶
If you want entities to be ignored for certain intents, you canadd the use_entities:false
parameter to the intent in your domainfile like this:
This means that entities for those intents will be unfeaturized and thereforewill not impact the next action predictions. This is useful when you havean intent where you don’t care about the entities being picked up. If you listyour intents as normal without this parameter, the entities will befeaturized as normal.
Note
If you really want these entities not to influence action prediction wesuggest you make the slots with the same name of type unfeaturized
Have questions or feedback?¶
We have a very active support community on Rasa Community Forumthat is happy to help you with your questions. If you have any feedback for us or a specificsuggestion for improving the docs, feel free to share it by creating an issue on Rasa CoreGitHub repository.
Slots are your bot’s memory. They act as a key-value storewhich can be used to store information the user provided (e.g their home city)as well as information gathered about the outside world (e.g. the result of adatabase query).
Most of the time, you want slots to influence how the dialogue progresses.There are different slot types for different behaviors.
For example, if your user has provided their home city, you mighthave a text
slot called home_city
. If the user asks for theweather, and you don’t know their home city, you will have to askthem for it. A text
slot only tells Rasa Core whether the slothas a value. The specific value of a text
slot (e.g. Bangaloreor New York or Hong Kong) doesn’t make any difference.
If the value itself is important, use a categorical
or a bool
slot.There are also float
, and list
slots.If you just want to store some data, but don’t want it to affect the flowof the conversation, use an unfeaturized
slot.
The Policy
doesn’t have access to thevalue of your slots. It receives a featurized representation.As mentioned above, for a text
slot the value is irrelevant.The policy just sees a 1
or 0
depending on whether it is set.
You should choose your slot types carefully!
You can provide an initial value for a slot in your domain file:
You can get the value of a slot using .get_slot()
inside actions.py
for example:
There are multiple ways that slots are set during a conversation:
If your NLU model picks up an entity, and your domain contains aslot with the same name, the slot will be set automatically. For example:
In this case, you don’t have to include the -slot{}
part in thestory, because it is automatically picked up.
To disable this behavior for a particular slot, you can set theauto_fill
attribute to False
in the domain file:
You can use buttons as a shortcut.Rasa Core will send messages starting with a /
to theRegexInterpreter
, which expects NLU input in the same formatas in story files, e.g. /intent{entities}
. For example, if you letusers choose a color by clicking a button, the button payloads mightbe /choose{'color':'blue'}
and /choose{'color':'red'}
.
You can specify this in your domain file like this:(see details in Domains)
The second option is to set slots by returning events in custom actions.In this case, your stories need to include the slots.For example, you have a custom action to fetch a user’s profile, andyou have a categorical
slot called account_type
.When the fetch_profile
action is run, it returns arasa.core.events.SlotSet
event:
In this case you do have to include the -slot{}
part in your stories.Rasa Core will learn to use this information to decide on the correct action totake (in this case, utter_welcome_premium
or utter_welcome_basic
).
Note
It is very easy to forget about slots if you are writingstories by hand. We strongly recommend that you build up thesestories using Interactive Learning with Forms rather than writing them.
text
¶User preferences where you only care whether or not they’vebeen specified.
Results in the feature of the slot being set to 1
if any value is set.Otherwise the feature will be set to 0
(no value is set).
bool
¶True or False
Checks if slot is set and if True
categorical
¶Slots which can take one of N values
Creates a one-hot encoding describing which of the values
matched.A default value __other__
is automatically added to the user-definedvalues. All values encountered which are not explicitly defined in thedomain are mapped to __other__
for featurization. The value__other__
should not be used as a user-defined value; if it is, itwill still behave as the default to which all unseen values are mapped.
float
¶Continuous values
max_value=1.0
, min_value=0.0
All values below min_value
will be treated as min_value
, the samehappens for values above max_value
. Hence, if max_value
is set to1
, there is no difference between the slot values 2
and 3.5
interms of featurization (e.g. both values will influence the dialogue inthe same way and the model can not learn to differentiate between them).
list
¶Lists of values
The feature of this slot is set to 1
if a value with a list is set,where the list is not empty. If no value is set, or the empty list is theset value, the feature will be 0
. The length of the list stored inthe slot does not influence the dialogue.
unfeaturized
¶Data you want to store which shouldn’t influence the dialogue flow
Slot Example Rasa Al
There will not be any featurization of this slot, hence its value doesnot influence the dialogue flow and is ignored when predicting the nextaction the bot should run.
Maybe your restaurant booking system can only handle bookingsfor up to 6 people. In this case you want the value of theslot to influence the next selected action (and not just whetherit’s been specified). You can do this by defining a custom slot class.
In the code below, we define a slot class called NumberOfPeopleSlot
.The featurization defines how the value of this slot gets converted to a vectorto our machine learning model can deal with.Our slot has three possible “values”, which we can represent witha vector of length 2
.
Slot List Rasa Example
| not yet set |
| between 1 and 6 |
| more than 6 |
Now we also need some training stories, so that Rasa Corecan learn from these how to handle the different situations: