Drupal 8.x

Hi,
I am having issues with custom submit handler for hook_form_handler. 

In detail:

I have added new form fields to core module 'path' and added custom submit handler to update my new added form fields.
I have got success connecting database table 'url_alias' and adding new fields to it and save values into db. 
Now the challenging part is to save values in form itself. When I submit the form, I see db updated with new values.
However, new form fields are still blank without submitted values. 

I am using the module Address but once the user entered an address and saved, I would like it to show it as a map instead of the write address. For example, if in the form they filled "Rue des Champs Elysées 3, Ixelles, Belgium" it would show the map where it is in Belgium instead of the address. (it can be google, openlayers, etc I am not picky)

Any idea of how to do that? 

I'm using a date exposed filter with a initial date and a final date. Its works fine but when the pagination item its selected the exposed filter loses his value.

This only happen on the exposed filter with date elements, the rest of exposed filters of the view maintain his corresponding values.

Could anyone please let me know how to solve this problem?

Thanks and regards

Hey guys, I did a d7 to d8 migration, and switched the theme from zen to bootstrap. In the D7 verison, the articles' metadata looked like this: https://imgur.com/h7WMiLA

Currently, my articles look like this: https://imgur.com/zqSiHrd

Is it possible to customize this field?

Thank you.

Hello,

I tested some tutorial like this : https://www.youtube.com/watch?v=4W8RGfMpVQ0 with no success and even worse, it had the effect of breaking the site (administration pages are no longer accessible). mytheme.info and mytheme.libraries files tree has changed...

Can you tell me how to do ?

Thanks a lot