Missing blocks startwith, result

MIT App Inventor Help
1

hello i am developing an app but there are a few blocks missing such as start with and resulth.
could anyone assist me with the structure of the flow below so that
so i am having trouble from the Handle Scan Results as there are blocks missing
could help is anyone has a way around it
i've attached screenshot of the current blocks

Screenshot 2025-06-06 135409
Screenshot 2025-06-06 1354091207×811 83.2 KB

HorizontalArrangement (for buttons)
Add 4 Button components inside:
"Examiners Mode"
"Fellows Mode"
"Graduates Mode"
"Admin Mode"
WebViewer (hidden, for API calls)
Notifier (to show messages)

QR Scanning Functionality
Add Barcode Scanner

when ExaminersMode.Click
  call BarcodeScanner1.DoScan
when FellowsMode.Click
  call BarcodeScanner1.DoScan
when GraduatesMode.Click
  call BarcodeScanner1.DoScan

Handle Scan Results

when BarcodeScanner1.AfterScan [result]
  if result = "" then
    call Notifier1.ShowAlert [message "Scan cancelled"]
  else
    if starts with result "EXM" then
      call WebViewer1.Url [https://your-google-script-url?action=scan&qrData=" & result & "&sheetName=Examiners"]
    else if starts with result "FEX" then
      call WebViewer1.Url [https://your-google-script-url?action=scan&qrData=" & result & "&sheetName=Fellows"]
    else if starts with result "GS" then
      call WebViewer1.Url [https://your-google-script-url?action=scan&qrData=" & result & "&sheetName=Graduates"]
    else
      call Notifier1.ShowAlert [message "Invalid QR code"]
    end if
  end if

Connect to Google Sheets

  1. WebViewer Setup
    The WebViewer will communicate with your Google Apps Script web app.
  2. Handle Responses
    Add a WebViewer.GotText event:
when WebViewer1.GotText [response]
  if response = "not_found" then
    call Notifier1.ShowAlert [message "Person not found"]
  else
    set ScanResultLabel.Text to response
  end if

Admin Features
Admin Screen
Create a new screen called AdminScreen with:
Password input field
"Generate QR Codes" button
"View Data" button

Admin Password Check

when AdminMode.Click
  call Notifier1.ShowTextInput [message "Enter admin password:"]
  
when Notifier1.AfterTextInput [response]
  if response = "admin123" then
    open screen AdminScreen
  else
    call Notifier1.ShowAlert [message "Wrong password"]
  end if

Printing Functionality
Since MIT App Inventor can't directly control thermal printers, there are two options:

Option 1: Use a Bluetooth Printer App
Install a printing app like "Printooth" on your Android device
Send data to it via Intent:

when PrintButton.Click
  launch activity "com.printooth.app" with data uri ("data:text/plain," & ScanResultLabel.Text)
2

Is your script url throws the return in textoutput or another format?

Do not use webviewer, instead use web block.

In the AfterScan event, if the block meet true logic set web url to apps script url along with required params and its value and add. Get request

Also catch the return result in webGot text.

When web got text event, 
If the get responseContent contains the text successful 
Then use true logic 
Else use false logic
3

Not sure not fully developed these blocks yet due to difficulty in setting up the Handle Scan Results part of the process as the start with and result blocks are missing in appinventor

4

Use one global variable to know which button is clickec.

Multiple ways are there, few methods are

  1. Initi a global variable with empty text. And set this variable value to your desired output on each button cluck. Imagine if examiner clicked set tbis variable to 1 and check the value of this variable after scan.

AfterScan triggered add elseif then block

If get global variable val=1
Then set web url to examiner script url and follow the same for others using elseif blovk

Method 2. In the afterscan chevk which button is clicked using when any button clicked

When any button clicked
If the get componet = examiner button
Then set web url to examiner script url...

Else if // add your codes

5

One way (there are other methods you could use), this assumes your "piece" is at the beginning:

image

6

Check your Project Properties to make sure you have
Blocks Toolkit = default

image
image939×754 63.1 KB

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