Having Problem with the Colored Dots for AI2 Tutorial

[Susan Mitchell]

- Are you using MIT App Inventor Classic, MIT App Inventor 2, or something else (what?)
MIT App Inventor 2

- What OS are you using? (e.g, MacOS 1.8, Windows 8, ...)
Android 4.2

- What browser are you using (e.g, Chrome version 30, Firefox 24, IE 8, ...)
Firefox, latest version

Has anyone successfully implemented (run) the Colored Dots for AI2 tutorial?

I've done it and it's not working correctly. When I click the Customize Brush button on Screen1, I receive the message, "The operation select list cannot accept the arguments: *empty-string*2".

It appears that the cause of the error is that the arguments created in the Screen1 list in "when openBrushPicker.Click" are not being received correctly by "when Brush_Picker.Initialize". I've changed the order in which the argument values are received (i.e. reversed "set global numberOfColors to" and "set currentColor to" and, sure enough, I get the same error message, but with the index altered: "The operation select list cannot accept the arguments: *empty-string*1".

[Taifun]

you have to test this functionality after building your app,

this will not work in the AI Companion app

Current issues with the AI Companion app:

1. It can't pass values from one screen to another
2. If you close a screen the OtherScreenClosed event will not be triggered but the Initialize event instead
3. The close application block does not work

Taifun

---

Trying to push the limits of App Inventor! Snippets and Tutorials from Pura Vida Apps by Taifun.         

[Susan Mitchell]

I tested it using my Android phone via wifi (I did NOT use the AI emulator). I've tested all of the other tutorials I've done this way and they work fine.

[Taifun]

as already said, you have to test this functionality after building your app,

this will not work in the AI Companion app

Taifun

[lynf...@gmail.com]

We also tried this on AI 2 and on an Android phone, spent all week trying to get it to work. We have the exact same problems. Please fix this as we are going to work with our girls this week.

Thank youl.

[SteveJG]

What Taifun seems to be saying is you need to build the apk.  After building the apk, load the apk on your device and try it.  I hope that will work, but do not know.  He provides great advice.

What is important is some things are impossible using AICompanion with WiFi or USB or on the emulator.  Taifun provided a list of things that make people want to pull their hair out.  Until those issues are ameliorated, sometimes you have to build the app and load it on your phone.

Please confirm you have tried that.    Another thing you might do is upload your existing aia file.   Someone here will try it out.

People here really want to help.

Regards,

Steve

[Lyn]

Ah, I had misread the above exchange-- I thought that Susan was answering Taifun rather than vice versa.

In that case, I revise my request: Regarding these known current issues
Please address and correct them as soon as you can. As far as our Technovation Challenge goes in Week 4, we have not learned apk and such, we are only working with emulators and AI Companion.

Our mentor will go ahead and try the apk now, however our beginner students have not encountered tutorials that teach apk etc.

Thank you.

[Lyn]

Okay our mentor says that solution worked. I have no idea what y'all are talking about :)

In the interest of helping other beginners, perhaps a link here or more specifics of explaining your solution.

Additionally, this needs to be noted on the Colored Dots tutorial page.
http://appinventor.mit.edu/explore/ai2/colored-dots.html
Nowhere on the tutorial does it say that it won't work on the Companion, or that it needs to be built into apk.

When you are trying to interest new programmers, you can't have an entire tutorial fail this early (Day 3, tutorial 11) in the game.

Thanks.

[SteveJG]

We are happy you and students are up and running.  

Taifun,

Can you get someone at MIT to get the caveat into the Colored Dots tutorial.   I do not know how to request that.

-- Steve

We are happy you and students are up and running.

[Taifun]

@Steve: all website and tutorial issues you can assign to Shaileen, I already did that...

Taifun

[SteveJG]

@Lyn ... the tutorial should have some new wording soon..

@Taifun .. thanks.

-- Steve

[Shaileen Pokress]

Hi all,

I apologize for the misinformation in the tutorial. App Inventor 2 is a big step up from using multiple screens in App Inventor 1, in that AI2 at least lets you navigate between two or more screens. However, it does not properly pass results back and forth, and that is the error in the Colored Dots tutorial.

We rely on people in the field reporting these things to us, so thank you. 

The tutorial is being updated right now.

Thanks,
Shay Pokress

[Susan Mitchell]

I now understand what Taifun was trying to tell me. So, I built the apk and loaded it on my device. He was right -- I can go to the Brush_Picker screen, I no longer get the error message, and the correct values are passed to the Brush_Picker screen. And the Brush_Picker screen works.

I am having trouble now when I return back to Screen1, but I'll work on that and make another post if necessary. Thanks!

[arguellesjo...@gmail.com]

Noong Lunes, Pebrero 24 2014 03:31:30 UTC+8, si Susan Mitchell ay sumulat:

Hi I tried Colored Dots for MIT App 2. The second tinydB1.Storevalue in notifier.aftertextinput is wrong it should be current color not numberofcolor. My problem is when I press back button of my cellphone "cannot accept the arguments:*empty-string*3 appear. Please help me thank you. :D

[Taifun]

[Taifun]

This is the close button in my phone not a user interface button. The error appear when i try to close the aplication while i'm in the brush picker screen.. :D Thank you please help me

you might want to start a new thread, and

you might want to provide a screenshot of your relevant blocks

PS: Please keep the discussion in the forum since I may be busy when you ask and you may get a faster response from the forums since there are many people monitoring them.

[mossoba...@gmail.com]

Hi, I was hoping to find "Colored Dots" revised by now. Please kindly let us know if anything is coming. I tried this tutorial many times using the .apk file to my phone and it is working only partially . Thank you.

[Taifun]

using the apk file, it should work perfectly!

what does not work for you?

[mossoba...@gmail.com]

THank you Taifun :

1. After storing few colors on screen2

2. I can return to screen1 and I can use only the last stored color.
3. When I go to stored colors, I can pick one.

4. BUT THEN : I cannot draw any dot anymore AT ALL not even with the default black.

Tks.again.

[SamMc...@student.yanceync.net]

I built the app, but the screen won't change. I keep getting the string error.

On Saturday, February 22, 2014 8:57:01 AM UTC-5, Taifun wrote:

you have to test this functionality after building your app,

this will not work in the AI Companion app

Current issues with the AI Companion app:

1. It can't pass values from one screen to another
2. If you close a screen the OtherScreenClosed event will not be triggered but the Initialize event instead
3. The close application block does not work

Taifun

---

Trying to push the limits of App Inventor! Snippets and Tutorials from Pura Vida Apps by Taifun.         

This email has been sent to you by a student in Yancey County Schools.

[Shaileen Pokress]

Mossoba,

This tutorial was updated on February 22nd. Are you using the APK file that is available on the MIT website as part of the tutorial? If you are building the APK from the project you built yourself, please get the .aia (using the Project --> "Export Selected Project (.aia) to my computer menu" option) and then post it here so we can take a look at your blocks.

Thanks,
Shay

[mossoba...@gmail.com]

Hi Shay,

Thank you for your answer, here is my aia file to be looked at, as you suggested.

Thank you.

Youssef Mossoba

[d.brian...@gmail.com]

Hi Youssef

In your resetcolorbutton.click, you are missing set RadiusTextBox.text to 3.

Brian

[d.brian...@gmail.com]

I spent three hours trying to diagnose this. You got it! My app is working fine now. Thank you!