Slotfilling

Check this Documentation

Or Look at this Tutorial in Spanish with Mizar.

Slotfilling help us to interrupt prompts when asking a value for a Variable. Is uncommonly used but there isn't information about this behavior on Dialogflow, so thats why here we have an special part to show you how this tool could enhance our chatbots.

SlotFilling is an option that can be enabled when we are using fulfillment with our chatbot. This option makes our Chatbot not to complete the request/response behavior. It makes the bot to wait until all the parameters are fulfilled.

Is the backend way to require a parameter and trigger its own prompt.

Recomendations

• Slotfilling works for Defined Entities, either custom or system. We dont recommend you to try this with @sys.any entities, or entities not declared as entities.
• Use this feature when you want to incorporate more than one language for your bot, if not, you can use the requiredParameter option that Dialogflow allow us to use.
• In order to use Slotfilling perfectly I encourage you to check Entities.

Implementing SlotFilling

• First lets create an Entity called fruits and add some examples as coco, banana, and strawberry. -Then create an intent, name it choice_fruits and type in the Training Phrases a name of a fruit that you created before as an Entity.
• Your phrase should be able to become hightlighted and recognized as part of @fruits entity.
• Create another phrase as hardcoded text. my fruit is, fruit
• Enable fulfillment and Slotfilling.
• Right now try from your console and say a hardcoded text that we have written before.
• Our intent choice_fruits should be triggered but for some reason, the entity @fruits is blank. This is because we havent passed a fruit, and this is the case that we want to test slotfilling.
• On our backend lets create the Intent structure as shown bellow, remember also to require from our Chatbot core file.

PHP

if(intent('choice_fruits')){
// Do whatever you want
}

Node.js

ALPHA

Right now lets do the backend side

• In order to use slotfilling we need first to use our function to retrieve a parameter, I recommend you to use getContextParameter(Remember to leave an outputContext in this intent or an Intent before).
• Let's get this parameter as shown below

PHP

$fruitType = getContextParameter(0)['fruit'];

Node.js

ALPHA

Remember to put the name specificed of the variable, this is the value of the parameter that has the $(dollar sign), put it without that sign.

• Then let's do a check for the existence of this variable

PHP

if($fruitType){
// the variable exists so we can execute code
} else {
    // we dont get the value so its time to trigger a Prompt
}

Node.js

ALPHA

• If we dont get any value we can use the function triggerPrompt to ask the user for a Fruit

PHP

$prompt = ["Tell me your favourite fruit"];
$context = false;
$contextbody = [];

triggerPropmt($context,$contextBody,$prompt);

Node.js

ALPHA

With this implementation if the user dont provides a fruit and this intent is triggered, the bot will ask for the fruit, if the user dont respond with a available or recognized fruit this question will be done again and again, so make sure you have defined enough of your entities and your question is pretty clear.

If you got your fruit you are good to go.

Keep in Mind

Structure Templates can be used for slotfilling prompts, so dont hesitate to use it if you want to offer some chips to the user :)