fix bug when no bbox params are set

[cjohn001]

Hello together,
attached pull request fixes a bug which stops the object detector from working if no bbox parameters are provided in the MLKitView xml template. Sorry for the inconvenience.

Best regards,
Christoph

[cjohn001]

@NathanWalker, @triniwiz
it would be great if you could have a look at the second issue where the native view is null. The fix I provided works, but to my understanding the native view should never be null in the first place. I suspect that the issues is routed in a problem in core. I have seen timing related issues in the past when mixing different transition animations.

I am observing the problem when I am on a page with the MLKitView and than navigate away using the following code

this.navSrv.navigate(
		[
			{
				outlets: {
					primary: [
						'selection',
						'tab-select-diary-item',
						{
							outlets: {
								'outlet-0': ['search-tab'],
								'outlet-1': ['empty-tab1'],
								'outlet-2': ['empty-tab2'],
								'outlet-3': ['empty-tab3']
							}
						}
					]
				}
			}
		],
		{
			transition: { name: 'flipLeft' },
			clearHistory: true
		}
	);

This results in the following exception

***** Fatal JavaScript exception - application has been terminated. *****
NativeScript encountered a fatal error:
Uncaught TypeError: Cannot read properties of null (reading 'bounds')
at
onLayout(file: node_modules/@nativescript/mlkit-core/index.ios.js:422:0)
at layout(file: node_modules/@nativescript/core/ui/core/view/index.ios.js:87:0)
at layoutChild(file: node_modules/@nativescript/core/ui/core/view/view-helper/view-helper-common.js:102:0)
at layoutChild(file: node_modules/@nativescript/core/ui/core/view/view-common.js:804:18)
at onLayout(file: node_modules/@nativescript/core/ui/layouts/grid-layout/index.ios.js:165:20)
at layout(file: node_modules/@nativescript/core/ui/core/view/index.ios.js:87:0)
at layoutChild(file: node_modules/@nativescript/core/ui/core/view/view-helper/view-helper-common.js:102:0)
at layoutChild(file: node_modules/@nativescript/core/ui/core/view/view-common.js:804:18)
at onLayout(file: node_modules/@nativescript/core/ui/layouts/grid-layout/index.ios.js:165:20)
at layout(file: node_modules/@nativescript/core/ui/core/view/index.ios.js:87:0)
at layoutChild(file: node_modules/@nativescript/core/ui/core/view/view-helper/view-helper-common.js:102:0)
at layoutChild(file: node_modules/@nativescript/core/ui/core/view/view-common.js:804:18)
at onLayout(file: node_modules/@nativescript/core/ui/layouts/grid-layout/index.ios.js:165:20)
at layout(file: node_modules/@nativescript/core/ui/core/view/index.ios.js:87:0)
at layoutChild(file: node_modules/@nativescript/core/ui/core/view/view-helper/view-helper-common.js:102:0)
at layoutChild(file: node_modules/@nativescript/core/ui/core/view/view-common.js:804:18)
at onLayout(file: node_modules/@nativescript/core/ui/page/index.ios.js:476:12)
at layout(file: node_modules/@nativescript/core/ui/core/view/index.ios.js:87:0)
at layoutChild(file: node_modules/@nativescript/core/ui/core/view/view-helper/view-helper-common.js:102:0)
at layoutView(file:///app/ve<…>

Or is this a valid situation that the native view can be null before the object is released and the fix I did is simply required?

[NathanWalker]

Yes definitely timing in layout there. Your fix is a good one as layout will reengage afterwards.