This tutorial is the continuation part of previous QR scanner App. Here we are making real-world application with little modification in the logic. Please follow every step carefully.

This App Development consists two parts

1. creating backend using app script & Sheets.
2. Building an Android app using App Inventor.

1 creating backend using app script & Sheets.

Step 1: Create new Spread Sheet and add few values

Step 2: Create new App script and add the following code

var ss = SpreadsheetApp.openByUrl("Your Spread Sheet URL");
var sheet = ss.getSheetByName("daily_attendance");

function doGet(e){
  var action  = e.parameter.action;
  
  if(action == "in")
    return inTime(e);
   
  if(action == "out")
    return outTime(e);
  
}


function doPost(e){
  var action  = e.parameter.action;
  
  if(action == "in")
    return inTime(e);
   
  if(action == "out")
    return outTime(e);
  
}

function inTime(e){
  var id = e.parameter.id;
  var values = sheet.getRange(2,1,sheet.getLastRow(),1).getValues();
  
  for(var i = 0 ; i<values.length ; i++){
    if(values[i][0] == id){
      i=i+2;
      var in_time = Utilities.formatDate(new Date(), "IST", "HH:mm:ss");
      sheet.getRange(i,3).setValue(in_time);
      return ContentService.createTextOutput("Thank You ! Your In Time is "+in_time).setMimeType(ContentService.MimeType.TEXT);
    }
  }
  return ContentService.createTextOutput("Id Not Found").setMimeType(ContentService.MimeType.TEXT);
}


function outTime(e){
  var id = e.parameter.id;
  var values = sheet.getRange(2,1,sheet.getLastRow(),1).getValues();
  
  for(var i = 0 ; i<values.length ; i++){
    if(values[i][0] == id){
      i=i+2;
      var out_time = Utilities.formatDate(new Date(), "IST", "HH:mm:ss");
      sheet.getRange(i,4).setValue(out_time);
      return ContentService.createTextOutput("Thank You ! Your Out Time is "+out_time).setMimeType(ContentService.MimeType.TEXT);
    }
  }
  return ContentService.createTextOutput("Id Not Found").setMimeType(ContentService.MimeType.TEXT);
}

Step 3: Deploy script as web App.  Use the web App URL in Next Part.

2 Building an Android app using App Inventor.

Step 1:  Create new AppInventor project. Add following components,

Step 2: Create logic block as specified. Please change URL of the web app

Step 3: Build and run the app to check the output.