Implement warning when leaving an unsubmitted form

[Chartman123]

Fixes #319 by adding a warning

Signed-off-by: Christian Hartmann chris-hartmann@gmx.de

[Chartman123]

@jotoeri any ideas why the custom message isn't shown in the window.confirm() dialog?

[jotoeri]

Seems like just confirm should work. But to be honest, i currently can't tell you exactly, why. 😆

forms/src/components/AppNavigationForm.vue

Line 207 in 6c257ed

if (!confirm(t('forms', 'Are you sure you want to delete {title}?', { title: this.formTitle }))) {

[Chartman123]

@jotoeri Tried it with just confirm() but doesn't work either... Even with static text. Did just research and it seems that it doesn't accept custom text for the onbeforeunload event

[jotoeri]

Ok, sorry @Chartman123 i checked it once before quickly, but i definitely have not time to get into detail currently. Needs probably to be postponed.

[Chartman123]

No problem, I think the design parts are more important for 3.0 than this here :)

[susnux]

confirm and alert are not allowed within beforeunload.
Also all browser dropped support for custom messages, so you only can use the default one.

Chrome removed support for custom message in ver 51
Opera removed support for custom message in ver 38
Firefox removed support for custom message in ver 44.0
Safari removed support for custom message in ver 9.1

[susnux]

Currently every time you open the submit view a confirmation dialog is shown, see code comment.

Moreover if you click to stay on the site, an error is thrown in the console because the navigation gets canceled (as requested) by the navigation guard.
So we should add a catch block to the router.push calls on the TopBar component and ignore every navigation guard related errors.

[Chartman123]

@susnux Thanks for your input :) I'm also planning to move the warning to a modal. If you want, you can help me there. Everytime I tried it ended up being even worse 😆

[Chartman123]

@susnux I think I got this working as expected right now. I think we should merge this without the modal, so that we can take it as a basis for @hamza221's PR regarding the local storage.

[susnux]

Tested and works now perfectly!