Missing callback on error in decodeFromInputVideoDevice

[DrorBuhnik]

Where there is an issue inside decodeFromInputVideoDevice, the error is not propagate up via scanFailure observable, this leave the library user in undefined state without any option to recover
https://github.com/zxing-js/ngx-scanner/blob/master/src/app/modules/zxing-scanner/browser-code-reader.ts#L143-L146

This came up when testing on iPad which (for some reason known only to apple) doesn't like to use the back ("environment") camera

To Reproduce

1. Find the environment camera (via this.scanner.camerasFound.subscribe)
2. Instruct ngx-scanner to use the environment camera (e.g. if label contains 'back' string)
3. Get an error in console:
   OverconstrainedError { message: "Invalid constraint", constraint: "deviceId" }
4. No other feedback, no knowledge is passed to library user in any callback/observables

Expected behavior
The library user should receive an error via scanFailure observable

Smartphone
Device: Apple iPad Mini 2
OS: 12.1.4
Browser: Safari
Version: 12

[odahcam]

I can confirm this behavior once I experienced it lots of times in recently. I'm sorry I couldn't fix it yet, I'm pretty out of time.

[DrorBuhnik]

Right now I have a manual workaround that takes this code

ngx-scanner/src/app/modules/zxing-scanner/browser-code-reader.ts

Lines 143 to 146 in 8ff38b6

	} catch (err) {
	/* handle the error, or not */
	console.error(err);
	}

and add

            catch (err) {
                /* handle the error, or not */
                console.error(err);
                callbackFn();
            }

Is that a sufficient fix for you?

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This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.