How do you make a notification or icon to appear on the map, telling other user that a user is facing a emergency and needs help?

[chang_jun]

I am making a Emergency App right now, and for this map screen, my user gets to alert the surrounding user that he/she is facing a emergency and needs help by clicking the bottom right, yellow button. I've completed everything but I'm not sure what i set up will work as what I thought, can someone help or help me to improve the function?

Current Progress
Designer Page:

Blocks:

[ABG]

That user_nearby value procedure will send the app into a coma, calling itself infinitely.

And why is it trashing the TinyDB namespace?

Your listener Event trashes its input text.
(I don't support extensions, but your logic is egregious.)

[chang_jun]

It's actually a group project for me to use this website to create a app, my groupmate set up the blocks for the button to function in this page. And since we can't have more than one device to run the app, so I can't try if the block he set up would function or not. And also I don't understand how the block he set up works, so I am asking and looking for support here. Please forgive me if I have caused any inconvinience.

[ABG]

So why doesn't your friend test the code he wrote, and why doesn't he ask for help here himself?

[chang_jun]

Because we can only run the app on one device each time, so we can't tell if the notification going to pop up or alert the user around. And the reason he didn't ask here is because I am the one who is thinking to ask for help since I can't find any resources to help completing what we need, I only tell my groupmates when I've made progression, we all have different part of work to do for this project after discussion, which mean there's a lot of screen in our app, and not just this "map" screen. And at this point, because my groupmate ask for my help on this screen, so I did some research but couldn't find a way to set up this screen, and so I post a topic here to look for help.

[SteveJG]

@chang_jun

for this map screen, my user gets to alert the surrounding user that he/she is facing a emergency

What you want to do is to send a notification or message to nearby Android devices? It is not possible to send a notification/message to just people near you Sorry.

If you know the phone numbers or email addresses of those surrounding you can send text messages to those phones. Perhaps that is what you want to do?

Here is a way to send a text (sms) message to a single phone with your gps coordinates. How to text your Location to a Phone and Display the Location on a Google Map .

[chang_jun]

Yo Steve, thank you so much for helping! I've got everything set up according to your tutorial and things are all working well, I am able send and receive SMS! But there is some problem now that a runtime error (destinationAddress) often pops up on my computer screen, and the SMS keep getting sent again and again. Is there a solution or did I set up anything wrong?

App:

Blocks:

Problem display:

[ABG]

That Location Changed event is a blabbermouth

[Taifun]

Try latitude instead of altitude

Taifun

[chang_jun]

Oh yea, thanks for telling, my bad i didn't realise that mistake. But the error still exist, and when I pressed to send SMS, the SMS keep sending non-stop, can someone help? Thanks

[SteveJG]

@chang_jun

he SMS keep getting sent again and again. I

The sms resends whenever the LocationChanged event fires. Your sendLocation Procedure is sending a new location every time the sensor gets new coordinates. Remove the sendLocation. as shown and it should fix that issue. Only use a Button to use your sendLocation.

You have lots of other issues as others have pointed out too.

[chang_jun]

Oh I see how it works now, thank you! So sorry about that, my English isn't too good, I didn't understand what the others have pointed, i do always go through the replies tho, appreciate you people's help.