Testing for empty dictionaries

SylvainGa 8 days ago

So, the following code

if (data.isEmpty()) {

gives:
Error: Array Out Of Bounds Error

when it's "Lang.Dictionary {size: 0}"

Similarly,

if (data.size() == 0) {

Also gave the same error.

So what can I do to test its size so it doesn't crash?!?

Top Replies

SylvainGa 6 days ago in reply to FlowState +1

The var type = data.keys()[0]; was from the original developer. I assume he was expecting just one web request data to be returned at a time but I now piggy back two of them together. I'm now iterating…
jim_m_58 6 days ago in reply to SylvainGa +1

If it's not 200 it will be null in many cases/devices, but in that case, onBackgroundData won't be called so your main app doesn't see it.
Kyle.ConnectIQ 6 days ago in reply to FlowState +1

Your best option would be to use a try / catch for Application.ObjectStoreAccessException.

All Replies

0 jim_m_58 6 days ago in reply to SylvainGa

If it's not 200 it will be null in many cases/devices, but in that case, onBackgroundData won't be called so your main app doesn't see it.

0 andyj713 6 days ago in reply to SylvainGa

SylvainGa said:
Background.exit

Search the forum, you'll find as I and others have that this is glitchy. Do not assume it will happen, consider using application storage.

0 SylvainGa 6 days ago in reply to andyj713

Writing to application storage for background processes isn't available for older models.

0 andyj713 6 days ago in reply to SylvainGa

SylvainGa said:
Writing to application storage for background processes isn't available for older models.

That's true, devices before CIQ 2.4 don't have it, but devices before CIQ 2.3 don't have background. There aren't any 2.3 devices, there's a gap between 2.2 and 2.4 so all devices have either both or neither.

0 SylvainGa 6 days ago in reply to andyj713

Oh, that I didn't know. Si why did Garmin take the time to mention that? It only confuses for no good reason!

0 jim_m_58 6 days ago in reply to SylvainGa

Actually, for Application.Storage, it's CIQ 3.2 for setValue.

See forums.garmin.com/.../f5-can-t-save-to-storage-from-background-while-f6-and-others-can

0 SylvainGa 6 days ago in reply to jim_m_58

I'll stick with Background.exit then...

0 jim_m_58 6 days ago in reply to SylvainGa

I've pretty much had one or more apps with a background service running on every device I've used since backgrounding was introduced, and never had any issue with Background.exit. You can run into problems if you are trying to pass back too much data or the wrong type of data, but that I consider a bug in the app itself.

0 andyj713 6 days ago in reply to jim_m_58

jim_m_58 said:
Actually, for Application.Storage, it's CIQ 3.2 for setValue.

I read that as CIQ 3.2 for background, but the API docs say 2.4 otherwise. Great. Another argument for "has".

0 FlowState 6 days ago in reply to jim_m_58

jim_m_58 said:
Actually, for Application.Storage, it's CIQ 3.2 for setValue.

See forums.garmin.com/.../f5-can-t-save-to-storage-from-background-while-f6-and-others-can

Actually, the requirement is CIQ 3.2 for Storage.setValue() from a background process. For non-background processes, the requirement is CIQ 2.4.

This is explicitly called out in the docs for Storage.setValue(), getValue(), deleteValue() and clearValues(), likely as a direct result of that bug report.

Here's the deleteValue() doc. The docs for setValue() and others is similar, in the sense that they all say "Since: API Level 2.4.0" but they also note that "ObjectStoreAccessException" is thrown from a background process on a device without 3.2.0 support. I chose deleteValue() for the screencap bc it's the doc with the least amount of text.

[https://developer.garmin.com/connect-iq/api-docs/Toybox/Application/Storage.html#deleteValue-instance_function]