Upload: Helper text for file constraints

[guygoldwasser]

Describe your motivation

B"H
Helper for valid types is common , and instead of compose a general usage when use the upload component,
it will be nice to have some default that can be use.

Similar, wonder if this requirement is also valid for max-file-size helper.

Describe the solution you'd like

e.g. flag to use the auto helper.
multi lingual support that can be overrule

Describe alternatives you've considered

create my own combination as part of the setUploadButton API

Additional context

No response

[yuriy-fix]

Dear @guygoldwasser ,
Do you mean you would like to see an automatically generated textual helper that would contain information about valid file types and other constraints?

Could you please also share if you have mock-ups or screenshots from your custom implementation?

[guygoldwasser]

B"H
Hi Yuri,
yes exactly. I just saw in many webapps there is always some legend about validity. it also make sense from ux perspective to give a guide or pre-direction for valid activities.
I didn't create yet my own solution, maybe will use the button placeholder, or compose a combination with span before or after.
BTW, assume having API like setHelperText like other input components, that can do the trick perfect for me too.

[yuriy-fix]

Would custom drop label address this issue for you? You can find an example of customising it in https://vaadin.com/docs/latest/components/upload#customization (you can also place a custom component in it)

[guygoldwasser]

Thanks,
that might work, but kind of abusing the drop l&f api.
I would prefer helper at the bottom, same with all other input component.
Sure I can push my own component, but then i need to do some css transitions and maintain it, as currently there is no placeholder for that.
Option B is to warp it up with VerticalLayout of same.

[rolfsmeds]

So this is not so much about automatically generating a helper text, but about API for setting a helper text manually so that it is displayed somewhere e.g. below the button and/or drop-label?

[guygoldwasser]

B"H
Hi,
what ever works for vaadin will work for me too.
if there is automatic helper, probably API will allow to overrule it.

[rolfsmeds]

I think a simple helper text API would be best. I'll rename the issue to reflect this.

Auto-generating the text would pose some tricky internationalization challenges that I don't think we want to tackle in the component.