Zalo Auth SDK using sign in with popup flow

Installation

npm run install

npm run start

Step 1: User click on the button "Sign in with Zalo"
Step 2: The client app initialize environment, and call login function from libs/zalo-auth-sdk.js
Step 3: On then zalo-auth-sdk.js, a function login is called. It build the url of the auth host, and open a popup window with the url.
Step 4: The popup window is opened on client side, and the user will input his/her credentials to sign in.
Step 5: After the user sign in, auth host will validate the app registration, user credentials, and create a token for the client app with user's information. Then, the auth host will redirect the popup window to the client app with the token.
Step 6: The zalo-auth-sdk.js will listen to the event from the popup window, process some logic to get the token, and close the popup window.
Step 7: The client app will receive the token from the zalo-auth-sdk.js, and store it in the local storage. If have any problem, the client app will show the error message.