Update to create a notification channel for SDK 26 and up

[pauly815]

PR Checklist

• [ x] The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/CONTRIBUTING.md#commit-messages.
• [ x] There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
• [ N/A] All existing tests are passing
• [ N/A] Tests for the changes are included

What is the current behavior?

#136
#124

What is the new behavior?

Updated background-http.android.ts to check the current SDK version. If SDK 26 or higher, a default notification channel is created and set in the notification config.

This update has been tested on a Samsung S8 emulator running Android 8 and a Samsung S6 running Android 7.

One thing to note, I tried to use the Build.VERSION_CODES.O constant but it didn't seem to work when running on a Samsung S6 with Android 7.

Fixes/Implements/Closes #[136].

[pauly815]

Just realized that this is like Pull Request #126. I am using nativescript angular. Is there any update on a resolution cause my app won't work in Android 8 without these changes.

[lini]

Thank you for the pull request. I reviewed the code and have two suggestions to improve it:

• The tns-platform-declarations reference uses API level 17, so trying to run a TypeScript compiler on the background-http plugin source files will fail because of the new methods (from API 26) in the code. This can probably be fixed with a simple declare var android; somewhere at the top of the file.

• I see that there are two places in the code where you need to create a channel and this is done in the same way. Perhaps it will be easier to maintain if you extract the code to a private method and call it where needed.

[pauly815]

@lini
I made updates per your suggestions. I re-tested on the same emulator and device as before to confirm the fix still works with the new changes.

[zbranzov]

Hi @pauly815 ,
Can you send an app so we can reproduce the issue?
Currently, using the demo-angular sample from the repository, we are unable to reproduce your case. We are testing on Nexus 5x and Pixel 2 (both Android 8.1) and latest plugin version. Additionally, the fix seems to duplicate a native code from the native library that plugin is using https://github.com/gotev/android-upload-service/blob/e1528d3b5049a10817fdfb8745d35e7ba580a37f/uploadservice/src/main/java/net/gotev/uploadservice/UploadTask.java#L126

[pauly815]

@zbranzov
I can't send the app that I'm having the issue with but I'll see if I can replicate the problem with the demo-angular app. Maybe it's a plugin conflict issue.

[pauly815]

@zbranzov
Looks like the latest 3.2.6 update resolved the issue. I was able to upload in my app without the fix in this pull request.