How to do this simple thing

This section introduces what the building block does. Bear in mind a user could land here from a search result so we may need to add a little context, redefine abbreviations, or otherwise help them orient themselves.

Example

Introduce the example, what are we about to do or see?

Before diving into the code samples, define the placeholders used by the code samples that will follow. These should follow our guidelines for placeholders used throughout Nexmo Developer.

Key Description
NEXMO_NUMBER Nexmo Number to call.

Prerequisites

Create an application

A Nexmo application contains the required configuration for your project. You can create an application using the Nexmo CLI (see below) or via the dashboard. To learn more about applications see our Nexmo concepts guide.

Install the CLI

npm install -g nexmo-cli

Create an application

Once you have the CLI installed you can use it to create a Nexmo application. Run the following command and make a note of the application ID that it returns. This is the value to use in NEXMO_APPLICATION_ID in the example below. It will also create private.key in the current directory which you will need in the Initialize your dependencies step

Nexmo needs to connect to your local machine to access your answer_url. We recommend using ngrok to do this. Make sure to change demo.ngrok.io in the examples below to your own ngrok URL.

nexmo app:create "Example Application" http://demo.ngrok.io/webhooks/answer http://demo.ngrok.io/webhooks/events --keyfile private.key
Install dependencies

npm install express body-parser
Initialize your dependencies

Create a file named interesting.js and add the following code:

Copy to Clipboard 
const app = require('express')()
const bodyParser = require('body-parser')

app.use(bodyParser.json())

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Write the code

Add the following to interesting.js:

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app
  .get('/webhooks/answer', onInboundCall)
  .post('/webhooks/dtmf', onInput)

app.listen(3000)

View full source

Run your code

Save this file to your machine and run it: 

node interesing.js

Prerequisites

Create an application

A Nexmo application contains the required configuration for your project. You can create an application using the Nexmo CLI (see below) or via the dashboard. To learn more about applications see our Nexmo concepts guide.

Install the CLI

npm install -g nexmo-cli

Create an application

Once you have the CLI installed you can use it to create a Nexmo application. Run the following command and make a note of the application ID that it returns. This is the value to use in NEXMO_APPLICATION_ID in the example below. It will also create private.key in the current directory which you will need in the Initialize your dependencies step

Nexmo needs to connect to your local machine to access your answer_url. We recommend using ngrok to do this. Make sure to change demo.ngrok.io in the examples below to your own ngrok URL.

nexmo app:create "Example Application" http://demo.ngrok.io/webhooks/answer http://demo.ngrok.io/webhooks/events --keyfile private.key
Install dependencies

Add the following to build.gradle:

compile 'com.nexmo:client:4.0.0'

Write the code

Add the following to the main method of the DtmfInput class:

Copy to Clipboard 
 */
Route answerRoute = (req, res) -> {
    TalkAction intro = new TalkAction.Builder("Hello. Please press any key to continue.").build();

    InputAction input = new InputAction.Builder()
            .eventUrl(String.format("%s://%s/webhooks/dtmf", req.scheme(), req.host()))
            .maxDigits(1)
            .build();


    res.type("application/json");

    return new Ncco(intro, input).toJson();
};

/*
 * Route which returns NCCO saying which DTMF code was received.
 */
Route inputRoute = (req, res) -> {
    InputEvent event = InputEvent.fromJson(req.body());

    TalkAction response = new TalkAction.Builder(String.format("You pressed %s, Goodbye.",
            event.getDtmf()
    )).build();

    res.type("application/json");

    return new Ncco(response).toJson();
};

Spark.port(3000);
Spark.get("/webhooks/answer", answerRoute);

View full source

Run your code

We can use the application plugin for Gradle to simplify the running of our application. Update your build.gradle with the following:

apply plugin: 'application'
mainClassName = project.hasProperty('main') ? project.getProperty('main') : ''

Run the following gradle command to execute your application, replacing com.nexmo.quickstart.voice with the package containing DtmfInput:

gradle run -Pmain=com.nexmo.quickstart.voice.DtmfInput

Prerequisites

Create an application

A Nexmo application contains the required configuration for your project. You can create an application using the Nexmo CLI (see below) or via the dashboard. To learn more about applications see our Nexmo concepts guide.

Install the CLI

npm install -g nexmo-cli

Create an application

Once you have the CLI installed you can use it to create a Nexmo application. Run the following command and make a note of the application ID that it returns. This is the value to use in NEXMO_APPLICATION_ID in the example below. It will also create private.key in the current directory which you will need in the Initialize your dependencies step

Nexmo needs to connect to your local machine to access your answer_url. We recommend using ngrok to do this. Make sure to change demo.ngrok.io in the examples below to your own ngrok URL.

nexmo app:create "Example Application" http://demo.ngrok.io/webhooks/answer http://demo.ngrok.io/webhooks/events --keyfile private.key
Install dependencies

composer require slim/slim:^3.8

Write the code

Add the following to index.php:

Copy to Clipboard 
$app = new \Slim\App;

$app->get('/webhooks/answer', function (Request $request, Response $response) {
    $uri = $request->getUri();
    $ncco = [
        [
            'action' => 'talk',
            'text' => 'Please enter a digit'
        ],
        [
            'action' => 'input',
            'eventUrl' => [
                $uri->getScheme().'://'.$uri->getHost().':'.$uri->getPort().'/webhooks/dtmf'
            ]
        ]
    ];

    return $response->withJson($ncco);
});

$app->post('/webhooks/dtmf', function (Request $request, Response $response) {
    $params = $request->getParsedBody();

    $ncco = [
        [
            'action' => 'talk',
            'text' => 'You pressed '.$params['dtmf']
        ]
    ];

    return $response->withJson($ncco);
});

$app->run();

View full source

Run your code

Save this file to your machine and run it: 

php -t . -S localhost:3000

Prerequisites

Create an application

A Nexmo application contains the required configuration for your project. You can create an application using the Nexmo CLI (see below) or via the dashboard. To learn more about applications see our Nexmo concepts guide.

Install the CLI

npm install -g nexmo-cli

Create an application

Once you have the CLI installed you can use it to create a Nexmo application. Run the following command and make a note of the application ID that it returns. This is the value to use in NEXMO_APPLICATION_ID in the example below. It will also create private.key in the current directory which you will need in the Initialize your dependencies step

Nexmo needs to connect to your local machine to access your answer_url. We recommend using ngrok to do this. Make sure to change demo.ngrok.io in the examples below to your own ngrok URL.

nexmo app:create "Example Application" http://demo.ngrok.io/webhooks/answer http://demo.ngrok.io/webhooks/events --keyfile private.key
Install dependencies

pip install 'flask>=1.0'
Initialize your dependencies

Create a file named handle-user-input.py and add the following code:

Copy to Clipboard 
from flask import Flask, request, jsonify
from pprint import pprint

app = Flask(__name__)

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Write the code

Add the following to handle-user-input.py:

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@app.route("/webhooks/answer")
def answer_call():
    for param_key, param_value in request.args.items():
        print("{}: {}".format(param_key, param_value))
    input_webhook_url = request.url_root + "webhooks/dtmf"
    ncco =[
        {
            "action": "talk",
            "text": "Hello, please press any key to continue."
        },
        {
            "action": "input",
            "maxDigits": 1,
            "eventUrl": [input_webhook_url]
        }
    ]
    return jsonify(ncco)



@app.route("/webhooks/dtmf", methods=['POST'])
def dtmf():
    data = request.get_json()
    pprint(data)
    ncco =[
        {
            "action": "talk",
            "text": "You pressed {}, goodbye".format(data['dtmf'])
        }
    ]
    return jsonify(ncco)

View full source

Run your code

Save this file to your machine and run it: 

python3 handle-user-input.py

Prerequisites

Create an application

A Nexmo application contains the required configuration for your project. You can create an application using the Nexmo CLI (see below) or via the dashboard. To learn more about applications see our Nexmo concepts guide.

Install the CLI

npm install -g nexmo-cli

Create an application

Once you have the CLI installed you can use it to create a Nexmo application. Run the following command and make a note of the application ID that it returns. This is the value to use in NEXMO_APPLICATION_ID in the example below. It will also create private.key in the current directory which you will need in the Initialize your dependencies step

Nexmo needs to connect to your local machine to access your answer_url. We recommend using ngrok to do this. Make sure to change demo.ngrok.io in the examples below to your own ngrok URL.

nexmo app:create "Example Application" http://demo.ngrok.io/webhooks/answer http://demo.ngrok.io/webhooks/events --keyfile private.key
Install dependencies

gem install nexmo

Write the code

Add the following to dtmf.rb:

Copy to Clipboard 
helpers do
  def parsed_body
    JSON.parse(request.body.read)
  end
end

before do
  content_type :json
end

route :get, :post, '/webhooks/answer' do
  [
    {
      action: 'talk',
      text: 'Please enter a digit'
    },
    {
      action: 'input',
      eventUrl: ["#{request.base_url}/webhooks/dtmf"]
    }
  ].to_json
end

route :get, :post, '/webhooks/dtmf' do
  dtmf = params['dtmf'] || parsed_body['dtmf']

  [{
    action: 'talk',
    text: "You pressed #{dtmf}"
  }].to_json
end

View full source

Run your code

Save this file to your machine and run it: 

ruby dtmf.rb

Note the application section of the building_blocks construct is optional. If not used there will be no prerequisite section in the rendered block.

Try it out

What did the user just build? How should they use it? Add the instructions for how to demo the masterpiece the user has just created.

Further reading

Add resources for a user such as: