Track My Mood Project - Error Message (on iOS)


I'm running into an issue with the code for the Track My Mood project (Data Using Bar Graphs and Pie Charts module). I've followed the instructions provided in the project (screenshots are linked here and here

When I go to test the app out, I get the error message: invoke: unable to invoke method Clear in object of type boolean. Irritants: ()
Note: You will not see another error reported for 5 seconds.

Any ideas of where I'm going wrong?

Are you using iOS?

Yes, I'm using an iPad to run the Companion App to test it out.

I've moved your topic to the iOS category, another user will be able to help you soon! :slight_smile:


Have you checked if the components (methods, properties...) you are using are already implemented in IOS?
Does App Inventor Run on iOS Yet?

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I have not. How would I go about doing that? Keep in mind, these are classroom iPads so I don't have full access to settings.

Don't know what blocks you are using in your application? Can't you check if the blocks used in the app are already implemented using the link above?

Whoops! Sorry, I misunderstood your question.

The template that I downloaded didn't have the components included however the instructions for the project walked me through what to add. I didn't add anything that wasn't included in the instructions.

The Chart component isn't in the iOS release yet. We are almost finished implementing it and it should be in the next iOS version.

Understood, thanks! Do you know if there is another way to represent data for the time being?

There is a trick I think you can use. Basically, for each category you can nest two HorizontalArrangements within each other. You make the outer category "Fill Parent" and then set the WidthPercent of the inner to be the fraction of the data, e.g., (number of class observations)/(total observations) * 100. The outer then serves as a background (possibly transparent, but up to you) and the inner one draws the "bar" of the chart (set its background color to something useful, e.g., red, green, etc.).

Here's an example app that shows this working for 3 categories: iOSChartWorkaround.aia (2.5 KB)

It's important to note here that the Width/Height percents are calculated as a total of the screen's width/height, not the parent component. This is why in the project I have the horizontal arrangements on separate lines from their labels.

Awesome, thank you!

Oh that's interesting. I'll take a look at the code. Thanks again!