LIFF v2 starter app

This is a small web application that demonstrates the basic functionality of the LINE Front-end Framework (LIFF).

Deploy methods

Depending on how you want to use LIFF, choose one of these methods for deploying the LIFF v2 starter app:

• If you merely want to try the functions LIFF offers, see Use Heroku button to deploy the app without using the terminal
• If you want to develop a LIFF app using Heroku and Node.js, see Customize the app and deploy it on Heroku via the terminal
• If you want to develop a LIFF app using a server platform of your choice, see Use any other server platform

Use Heroku button to deploy the app without using the terminal

Follow the below instructions to deploy your app using the Heroku button and Node.js without customization.

What you'll need

Item	Description
LINE Messaging API channel	A channel forms the connection between your app and the LINE Platform. Create a channel on the LINE Developers console.
Heroku account (optional)	Heroku is a cloud service that lets you deploy and serve web apps for free. You don't need a Heroku account if you're deploying the app on another platform.

Deploy the app using 'Deploy to Heroku' button

1. Click Deploy to Heroku above.
2. On the "Create New App" page in Heroku, fill in the required information.
3. Click Deploy app.
4. Click View to confirm that your app is successfully deployed. You should see a page with the text "You have not assigned any value for LIFF ID".
5. Take a note of your app's URL (https://{Heroku app name}.herokuapp.com). You'll need it when you add the app to LIFF.

Add the starter app to LIFF

1. Follow the instructions on the page Adding a LIFF app.
2. Take a note of your LIFF ID, because you'll need it for the next part. The LIFF ID is the final part of the LIFF URL shown in the console: https://liff.line.me/{liffId}.
3. Locate the Scope option and click the Edit button.
4. Click the View all option and enable chat_message.write. This scope is required for the LIFF app to send messages on behalf of the user.
5. Change the status of LIFF app to Published.

Pass your LIFF ID to the app using an environment variable

1. In Heroku, go to Dashboard.
2. Select your app.
3. On the Settings tab, click Reveal Config Vars.
4. Enter a new key called MY_LIFF_ID with your LIFF ID as the value.
5. Click Add to save.
6. Browse back to your app's URL (https://{Heroku app name}.herokuapp.com) and confirm that your app is operational. You should see a number of buttons, such as Open External Window and Close LIFF App.

For more information about how to try the app, see Trying the app.

Checking logs

To get more information, you can check your app's logs using Heroku's GUI or Heroku CLI.

Check your app's logs using Heroku's GUI

To get more information, check your app's logs online:

1. In Heroku, go to Dashboard.
2. Select the app you just created.
3. In the top-right corner, click More.
4. Click View logs.

You'll find the log under Application Logs.

Check your app's logs using Heroku CLI

1. Log in to Heroku from the command line (if you haven't already).

   $ heroku login

2. Check the logs.

   $ heroku logs --app {Heroku app name} --tail

Customize the app and deploy it on Heroku via the terminal

Follow the below instructions to deploy your customized app using Heroku and Node.js.

Install the app on your local machine

1. Make sure you have the following installed.

   • Git
   • Node.js
   • Items listed here

2. Clone the line-liff-starter GitHub repository.

   git clone https://github.com/line/line-liff-v2-starter

3. cd into line-liff-v2-starter directory.

4. Install the dependencies by running:

   $ npm install

Link your local repository to Heroku

1. Log in to Heroku from the command line.

   $ heroku login

2. Create a named Heroku app.

   $ heroku create {Heroku app name}

3. Take a note of your app's URL (https://{Heroku app name}.herokuapp.com). You'll need it when you add the app to LIFF.

4. Add a remote for Heroku to your local repository.

   $ heroku git:remote -a {Heroku app name}

Add the starter app to LIFF

1. Follow the instructions on the page Adding a LIFF app.
2. Take a note of your LIFF ID, because you'll need it for the next part. The LIFF ID is the final part of the LIFF URL shown in the console: line://app/{liffId}

Customize and deploy the app via terminal

1. Set your LIFF ID using an environment variable.

   heroku config:set MY_LIFF_ID={liffId}

2. Copy your environment variable into the .env file for local testing.

   Heroku recommends setting up an .env file to use an environment variable in a local environment.

   $ heroku config:get MY_LIFF_ID -s  >> .env

   Note: Don't commit the .env file to GitHub. To exclude it, add the .env file to your .gitignore.

3. Customize your app. For more information about available LIFF methods, see API reference.

4. Run the app locally to preview your changes:

   heroku local

   View the app by browsing to localhost:5000.

5. If you're happy with your changes, stage, commit, and deploy the app.

   $ git add .
   $ git commit -m "My first commit"
   $ git push heroku master

6. Browse to your app's URL (https://{Heroku app name}.herokuapp.com) and confirm that your app is operational. You should see a number of buttons, such as Open External Window and Close LIFF App.

7. Lastly, check whether your channel status is Published.

For more information about how to try the app, see Trying the app.

Checking logs

To get more information, check your app's logs using Heroku's GUI or Heroku CLI. Refer to this section for more information.

Deploy the app using any other server platform

Follow the below instructions to deploy your app using the server platform of your choice.

Prerequisites

Item	Description
LINE Messaging API channel	A channel forms the connection between your app and the LINE Platform. Create a channel on the LINE Developers console.

Clone the repository

1. Clone the line-liff-starter repository.

   git clone https://github.com/line/line-liff-v2-starter

2. cd into line-liff-v2-starter directory.

Prepare your app and server

1. Set the useNodeJS variable to false in public/liff-starter.js.

   const useNodeJS = false;  

2. Remove Heroku and Node.js specific files (app.json , index.js, package.json, and Procfile) from your workspace.

3. Host the files on a web server.

Add the starter app to LIFF

1. Follow the instructions on the page Adding a LIFF app.

2. Take a note of your LIFF ID, because you'll need it for the next part. The LIFF ID is the final part of the LIFF URL shown in the console: line://app/{liffId}

3. Set your LIFF ID to the defaultLiffId variable in public/liff-starter.js.

   const defaultLiffId = "{liffId}"; 

Trying the app

Try the app in LINE

You can open your LIFF app in LINE by creating a simple link from any chat:

1. In any LINE chat, type line://app/{liffId} and send the message. (For example, if your LIFF ID is 123, send the message line://app/123.)
2. Tap the link in your own message.
3. Agree to grant the required permissions to the LIFF app.

Try the app in your browser

To open your LIFF app in your browser, enter the app's Heroku URL: https://{Heroku app name}.herokuapp.com

App features

You'll find the following buttons in the starter app.

ℹ️ Some buttons are available only in either LINE's in-app browser or in a regular browser. See also the API reference.

Button	Description	LINE browser	Regular browser
Open External Window	Opens https://line.me in LINE's in-app browser.	✅	✅
Close LIFF App	Closes the LIFF app.	✅	❌
Open QR Code Reader	Opens the QR code reader and outputs the result. ⚠️ Due to a technical issue, liff.scanCode() is temporarily unavailable on LINE for iOS v9.19.0 and later.	✅	❌
Send Message	Sends a sample message on behalf of the user if the LIFF app is opened in the chat screen.	✅	❌
Get Access Token	Gets the current user's access token.	✅	✅
Get Profile	Gets the current user's profile.	✅	✅
Open Share Target Picker	Displays the target picker (screen for selecting a group or friend) and sends a sample message to the selected target.	✅	❌
Log In	Performs LINE Login for web apps. Once the user is authenticated and authorized, the LIFF app will be able to obtain information such as access token and user profile.	❌	✅
Log Out	Logs out the user.	✅	✅

For API calls associated with the buttons, see Calling the LIFF API.