Introduction

Duration is 3 min

Last Updated: 28/05/2019

This tutorial will walk you through the steps to create a location-aware Alexa Skill.

At the end of this tutorial, you will have created an Alexa Skill in which you can search for nearby places. For example:

Alexa, show me nearby Sushi in Seattle.

We found a nearby sushi place near Seattle! Sushi Kanpai is 0.3 miles away and is located at 900 8th Ave Seattle, WA 98104

This tutorial demonstrates the use of two HERE Location Services APIs: Geocoder and Places.

As an Alexa application developer, you may want to integrate a places search if you are building:

  • A restaurant review application. Users can search for nearby restaurants and then write reviews about the restaurant.
  • A ridesharing application. A place can serve as an origin or destination point for the trip.
  • A tour guide application. The virtual tour guide can suggest landmarks to visit in the user's area.

What is the Geocoder API?

The Geocoder REST API enables developers to convert street addresses to geo-coordinates and vice-versa with forward geocoding, including landmarks, and reverse geocoding.

The HERE Geocoder API is a REST API that allows you to:

  • Obtain coordinates for addresses
  • Obtain addresses or administrative areas for locations
  • Obtain coordinates for known landmarks.

What is the Places API?

The Places (Search) API is a REST API that allows you to build applications where users can search for places and receive detailed information about selected places.

What you'll need

Configure the Alexa Skill

Duration is 12 min

Navigate to the Alexa Developer Portal. If you don't already have an Amazon Developer account, go ahead and create one. If you already have an account, go ahead and sign in.

Once you are inside of the Alexa Skills Console, navigate to the Skills page, located in a dropdown under Your Alexa Consoles. From there, click Create Skill.

creating a new skill
Figure 1. creating a new skill

Give your skill a name. I named mine HERE Places on Alexa. Feel free to choose your own name. Choose a custom model and start from scratch.

You should now be presented with your skill's console page:

console page
Figure 2. console page

On the left-hand sidebar, you should see a button that says JSON Editor. Go ahead and click that. Inside the JSON Editor is where we will configure invocations, intents, and slots for our skill.

  • An invocation is a phrase one can say to launch the Alexa Skill. In our application, we'll be using HERE Maps as the invocation.
  • An intent is a phrase one can say to launch a specific function or action within the Alexa Skill. For example, one of the intents we'll be using in this skill will be the phrase show me sushi near Seattle.
  • A slot is a parameter within an intent. For example, in the intent phrase show me sushi near Seattle, two parameters we would like to parse would be sushi and Seattle. Sushi is the place category we'll be using for our search, while Seattle is the location we'll be using for our search. Slots are used to isolate certain values out of phrases uttered by the user.

Go ahead and paste the following JSON within the text field:

{
   "interactionModel": {
       "languageModel": {
           "invocationName": "here places",
           "intents": [
               {
                   "name": "SearchIntent",
                   "slots": [
                       {
                           "name": "Item",
                           "type": "AMAZON.Food"
                       },
                       {
                           "name": "Location",
                           "type": "AMAZON.AdministrativeArea"
                       }
                   ],
                   "samples": [
                       "show me nearby {Item} in {Location}",
                       "show me {Item} in {Location}",
                       "where is {Item} in {Location}",
                       "find me {Item} near {Location}"
                   ]
               },
               {
                   "name": "AMAZON.RepeatIntent",
                   "samples": []
               },
               {
                   "name": "AMAZON.HelpIntent",
                   "samples": []
               },
               {
                   "name": "AMAZON.StopIntent",
                   "samples": []
               },
               {
                   "name": "AMAZON.CancelIntent",
                   "samples": []
               }
           ],
           "types": []
       }
   }
}

Pasting this JSON will automatically populate the other values in the sidebar. Go ahead and click both the Save Model and Build Models buttons at the top of the screen.

Your screen should now look something like this:

pasted json
Figure 3. pasted json

Configure the Lambda Function

Duration is 10 min

So far, we've created the Alexa Skill and configured some basic properties. We'll need somewhere to host the code that controls our skill's logic.

We'll be employing the help of AWS Lambda functions for this task.

Navigate to Amazon Web Services website and sign into the console. If you don't already have an account, go ahead and create one.

In the AWS services search field, search for Lambda. Click the orange Create function button to create a new Lambda function.

When creating the Lambda function, select the AWS Serverless Application Repository radio button and search for alexa-skills-kit-nodejs-howtoskill.

creating lambda
Figure 4. creating lambda

Name your application and then click Deploy. The function may take about 20-30 seconds to deploy.

Once the resource has been deployed (you can confirm this by seeing a CREATE_COMPLETE notice), click on the resource to be taken to the code editor page.

Add HERE location services to the Skills

Duration is 25 min

In the previous step, we created an AWS Lambda function to host and execute our skill's logic.

Before we start writing code, let's head over to the AWS Marketplace to grab our application's keys. Sign up and create a new project inside the marketplace.

Under the JavaScript/REST section, click Generate App ID and App Code. Grab and save these keys, we'll be using them shortly.

Let's start modifying the skill's code.

editing code
Figure 5. editing code

The code that's already included comes from an example skill. This code is a good skeleton for what we'll build, but we'll want to modify some parts.

First things first, let's include our HERE keys and helper conversion variable.

const here = {
  id: 'YOUR-HERE-ID',
  code: 'YOUR-HERE-CODE'
};

const metersToMiles = 0.00062137;

Additionally, we'll be making HTTP requests, so let's include a helper method that will assist us with that.

const https = require('https');

function makeRequest(options) {
  return new Promise(((resolve, reject) => {
     const request = https.request(options, (response) => {
        let data = '';
        response.on('data', (chunk) => {
           data += chunk;
        });
        response.on('end', () => {
           resolve(JSON.parse(data));
        });
        response.on('error', (error) => {
           reject(error);
        });
     });
     request.on('error', function(error) {
        reject(error);
     });
     request.end();
  }));
}

The https module is already included, so no extra steps to install it are necessary.

Next, let's simplify the LaunchRequestHandler to fit our needs.

const LaunchRequestHandler = {
 canHandle(handlerInput) {
   return handlerInput.requestEnvelope.request.type === 'LaunchRequest';
 },
 handle(handlerInput) {
   const welcomeOutput = 'Welcome to HERE Places. Trying searching for a place category and a location. For example, try "show me sushi in Seattle"';
   return handlerInput.responseBuilder
     .speak(welcomeOutput)
     .reprompt(welcomeOutput)
     .getResponse();
 },
};

Now, let's get to the fun part: implementing HERE Location Services. Replace the RecipeHandler with this new SearchHandler, which handles our search logic.

const SearchHandler = {
  canHandle(handlerInput) {
     return handlerInput.requestEnvelope.request.type === 'IntentRequest' &&
        handlerInput.requestEnvelope.request.intent.name === 'SearchIntent';
  },
  handle(handlerInput) {
     const query = handlerInput.requestEnvelope.request.intent.slots.Item.value;
     const location = handlerInput.requestEnvelope.request.intent.slots.Location.value;

     const geocodeOptions = {
        host: 'geocoder.api.here.com',
        path: `/6.2/geocode.json?app_id=${here.id}&app_code=${here.code}&searchtext=${location}`,
        method: 'GET'
     };

     const errorMessage = `We didn't find any ${query} in ${location}`;

     return new Promise((resolve, reject) => {
        makeRequest(geocodeOptions).then((geocodeResponse) => {
           const coordinates = geocodeResponse.Response.View[0].Result[0].Location.DisplayPosition;

           const placesOptions = {
             host: 'places.api.here.com',
             path: `/places/v1/discover/search?at=${coordinates.Latitude},${coordinates.Longitude}&q=${query.replace(/ /g, '+')}&app_id=${here.id}&tf=plain&app_code=${here.code}`,
             method: 'GET'
           };

           makeRequest(placesOptions).then((placeResponse) => {
             const places = placeResponse.results.items;
             const examplePlace = places[0];
             if (examplePlace) {
               const successOutput = `We found a nearby ${query} place near ${location}! ${examplePlace.title} is ${(examplePlace.distance * metersToMiles).toFixed(1)} miles away and is located at ${examplePlace.vicinity}`;
               resolve(handlerInput.responseBuilder.speak(successOutput).getResponse());
             } else {
               resolve(handlerInput.responseBuilder.speak(errorMessage).getResponse());
             }

           }).catch((error) => {
             resolve(handlerInput.responseBuilder.speak(errorMessage).getResponse());
           });

        }).catch((error) => {
           resolve(handlerInput.responseBuilder.speak(errorMessage).getResponse());
        });
     });
  }
};

What's going on here?

  • First, we parse the intent to find the query (place category) and the location.
  • Next, we make a request to the HERE Geocoder API to translate the location string into actionable coordinates so we can use them in other services like routing, places, etc.
  • We then take the coordinates and the query and perform a places search.
  • The places search returns an array of results. The Alexa Skill presents information on the first result, including the name, distance, and address of the place.

You'll also want to modify the export at the end of the code to include the newly added SearchHandler.

exports.handler = skillBuilder
 .addRequestHandlers(
   LaunchRequestHandler,
   SearchHandler,
   HelpHandler,
   RepeatHandler,
   ExitHandler,
   SessionEndedRequestHandler
 )
 .addErrorHandlers(ErrorHandler)
 .lambda();

The code template has a few more lines that can be modified. Take a look at the Appendix section of this tutorial for the entire Lambda code block.

Make sure to save the modified code.

Connect Lambda Function to Alexa Skill

Duration is 8 min

Now that our code is complete, the next step is to connect it back to the Alexa Skill.

At the top of the Lambda function editor page, look for the string next to ARN.

finding ARN
Figure 6. finding ARN

Copy this string and navigate back to the Alexa Developer Console.

Click on the Endpoints button on the left sidebar. Inside of Default Region field, go ahead and paste your copied ARN string.

pasting ARN
Figure 7. pasting ARN

Test the Alexa Skill

Duration is 8 min

Almost done! So far you've configured the Alexa Skill, setup a Lambda function to control the skill's logic, and connected the Alexa Skill to the Lambda. Now, let's test the skill to make sure it is functioning properly.

In the Alexa Developer Console, click on the Test button on the top header. In this view, you can test your newly created skill.

To begin testing, click the switch that says Test is disabled for this skill. You are now able to test the skill by typing into the field or talking through your computer's microphone.

testing skill
Figure 8. testing skill

Here is an example interaction:

open here places

Welcome to HERE Places. Trying searching for a place category and a location. For example, try "show me sushi in Seattle"

show me sushi in Seattle

We found a nearby sushi place near Seattle! Sushi Kanpai is 0.3 miles away and is located at 900 8th Ave Seattle, WA 98104

If you'd like to deploy the skill to an Echo device, take a look at this handy guide.

Review

Duration is 1 min

Congratulations! You've successfully created a location-aware Alex Skill! In this tutorial, you've learned how to:

  • configure Alexa Skills
  • create AWS Lambda functions
  • write code to enable Alexa Skills
  • make calls the the HERE Location Services Geocoder and Places APIs
  • test Alexa Skills

This is just a basic example of what can be done with HERE Location Services, take a look at the HERE Developer blog to see more examples of creative and useful applications of HERE Location Services.

Appendix: Complete Lambda Function Code block

const Alexa = require('ask-sdk-core');
const https = require('https');

const metersToMiles = 0.00062137;

const here = {
  id: 'YOUR-HERE-ID',
  code: 'YOUR-HERE-CODE'
};

function makeRequest(options) {
  return new Promise(((resolve, reject) => {
     const request = https.request(options, (response) => {
        let data = '';
        response.on('data', (chunk) => {
           data += chunk;
        });
        response.on('end', () => {
           resolve(JSON.parse(data));
        });
        response.on('error', (error) => {
           reject(error);
        });
     });
     request.on('error', function(error) {
        reject(error);
     });
     request.end();
  }));
}

/* INTENT HANDLERS */
const LaunchRequestHandler = {
 canHandle(handlerInput) {
   return handlerInput.requestEnvelope.request.type === 'LaunchRequest';
 },
 handle(handlerInput) {

   const welcomeOutput = 'Welcome to HERE Places. Trying searching for a place category and a location. For example, try "show me sushi in seattle"';
   return handlerInput.responseBuilder
     .speak(welcomeOutput)
     .reprompt(welcomeOutput)
     .getResponse();
 },
};

const SearchHandler = {
  canHandle(handlerInput) {
     return handlerInput.requestEnvelope.request.type === 'IntentRequest' &&
        handlerInput.requestEnvelope.request.intent.name === 'SearchIntent';
  },
  handle(handlerInput) {

     const query = handlerInput.requestEnvelope.request.intent.slots.Item.value;
     const location = handlerInput.requestEnvelope.request.intent.slots.Location.value;

     const geocodeOptions = {
        host: 'geocoder.api.here.com',
        path: `/6.2/geocode.json?app_id=${here.id}&app_code=${here.code}&searchtext=${location}`,
        method: 'GET'
     };

     const errorMessage = `We didn't find any ${query} in ${location}`;

     return new Promise((resolve, reject) => {
        makeRequest(geocodeOptions).then((geocodeResponse) => {
           const coordinates = geocodeResponse.Response.View[0].Result[0].Location.DisplayPosition;

           const placesOptions = {
             host: 'places.api.here.com',
             path: `/places/v1/discover/search?at=${coordinates.Latitude},${coordinates.Longitude}&q=${query.replace(/ /g, '+')}&app_id=${here.id}&tf=plain&app_code=${here.code}`,
             method: 'GET'
           };

           makeRequest(placesOptions).then((placeResponse) => {
             const places = placeResponse.results.items;
             const examplePlace = places[0];
             if (examplePlace) {
               const successOutput = `We found a nearby ${query} place near ${location}! ${examplePlace.title} is ${(examplePlace.distance * metersToMiles).toFixed(1)} miles away and is located at ${examplePlace.vicinity}`;
               resolve(handlerInput.responseBuilder.speak(successOutput).getResponse());
             } else {
               resolve(handlerInput.responseBuilder.speak(errorMessage).getResponse());
             }

           }).catch((error) => {
             resolve(handlerInput.responseBuilder.speak(errorMessage).getResponse());
           });

        }).catch((error) => {
           resolve(handlerInput.responseBuilder.speak(errorMessage).getResponse());
        });
     });
  }
};

const HelpHandler = {
 canHandle(handlerInput) {
   return handlerInput.requestEnvelope.request.type === 'IntentRequest'
           && handlerInput.requestEnvelope.request.intent.name === 'AMAZON.HelpIntent';
 },
 handle(handlerInput) {
   const helpOutput = 'Trying giving us a query like "Show me sushi in Seattle"'
   return handlerInput.responseBuilder
     .speak(helpOutput)
     .reprompt(helpOutput)
     .getResponse();
 },
};

const RepeatHandler = {
 canHandle(handlerInput) {
   return handlerInput.requestEnvelope.request.type === 'IntentRequest'
           && handlerInput.requestEnvelope.request.intent.name === 'AMAZON.RepeatIntent';
 },
 handle(handlerInput) {
   const sessionAttributes = handlerInput.attributesManager.getSessionAttributes();

   return handlerInput.responseBuilder
     .speak(sessionAttributes.speakOutput)
     .reprompt(sessionAttributes.repromptSpeech)
     .getResponse();
 },
};

const ExitHandler = {
 canHandle(handlerInput) {
   return handlerInput.requestEnvelope.request.type === 'IntentRequest'
           && (handlerInput.requestEnvelope.request.intent.name === 'AMAZON.StopIntent'
               || handlerInput.requestEnvelope.request.intent.name === 'AMAZON.CancelIntent');
 },
 handle(handlerInput) {
   const requestAttributes = handlerInput.attributesManager.getRequestAttributes();
   const speakOutput = requestAttributes.t('STOP_MESSAGE', requestAttributes.t('SKILL_NAME'));

   return handlerInput.responseBuilder
     .speak(speakOutput)
     .getResponse();
 },
};

const SessionEndedRequestHandler = {
 canHandle(handlerInput) {
   console.log("Inside SessionEndedRequestHandler");
   return handlerInput.requestEnvelope.request.type === 'SessionEndedRequest';
 },
 handle(handlerInput) {
   console.log(`Session ended with reason: ${JSON.stringify(handlerInput.requestEnvelope)}`);
   return handlerInput.responseBuilder.getResponse();
 },
};


const ErrorHandler = {
 canHandle() {
   return true;
 },
 handle(handlerInput, error) {
   console.log(`Error handled: ${error.message}`);

   return handlerInput.responseBuilder
     .speak('Sorry, I can\'t understand the command. Please say again.')
     .reprompt('Sorry, I can\'t understand the command. Please say again.')
     .getResponse();
 },
};

const skillBuilder = Alexa.SkillBuilders.custom();

exports.handler = skillBuilder
 .addRequestHandlers(
   LaunchRequestHandler,
   SearchHandler,
   HelpHandler,
   RepeatHandler,
   ExitHandler,
   SessionEndedRequestHandler
 )
 .addErrorHandlers(ErrorHandler)
 .lambda();

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