Add more validation to destructive actions (CSRF + additional password checking)

[Glandos]

This also switches all such actions to POST requests.

Remaining topics:

• Use form.errors instead of translated strings
• Project deletion
• Project history deletion

[Glandos]

I was surprised by the fact that on authentication form, the CSRF error message is displayed directly from Flask_WTF, but this is always in English. In fact, there is an issue on that: pallets-eco/flask-wtf#401
The main issue with providing our own string is that we lose some information, since Flask_WTF is using different strings for different cases. And this error should never happen in a normal environment, so displaying it in English is not a real issue.
On the other hand, it seems better to have a translated application.

What do you think?

[zorun]

I have reworked project deletion to have its own form and to ask for the private code:

[zorun]

Same thing for the "Clear project history" modal, but I need help from someone who knows how to talk to bootstrap:

[zorun]

I was surprised by the fact that on authentication form, the CSRF error message is displayed directly from Flask_WTF, but this is always in English. In fact, there is an issue on that: wtforms/flask-wtf#401
The main issue with providing our own string is that we lose some information, since Flask_WTF is using different strings for different cases. And this error should never happen in a normal environment, so displaying it in English is not a real issue.
On the other hand, it seems better to have a translated application.

What do you think?

Yes, I was also surprised about the built-in CSRF error messages.

I think it's fine to handle errors through flash messages, it shouldn't happen in normal cases (and practically speaking it's hard to handle this as form errors...)

Let me know what you think of the new code.

[Glandos]

For the edit project form, I changed the interaction:

• Button is normal at first, and changed to danger when clicked. Otherwise, it is hard to notice a change with the mouse over it.
• If the button lose focus, confirmation state is lost.
• Attach the event at document load, and not on each form click.

[Glandos]

Forms are already translating interesting strings, so I'd like to use them instead of flashing a new message.
For this, we need a function (in utils.py?) like this:

def flash_form_errors(form, title):
    if len(form.errors) == 0:
        return None
    elif len(form.errors) == 1:
        # I18N: Form error with only one error
        return _("{title}: {description}").format(title=title, error=form.errors.popitem()[1][0])
    else:
        error_list = "</li><li>".join(str(error) for (field, errors) in form.errors.items() for error in errors)
        errors = f"<ul><li>{error_list}</li></ul>"
        # I18N: Form error with a list of errors
        return Markup(_("{title}<br />{errors}").format(title=title, errors=errors))

And it can be used:

        flash(
            flash_form_errors(form, _("Error deleting project history")),
            category="danger",
        )

Then all strings from validators are displayed as-is, potentially in a list, if there more than one of them. I voluntarily removed the field name, otherwise the flashing message would have been too long.

[Glandos]

Use flash_form_errors

[Glandos]

Use flash_form_errors

[Glandos]

I'll gladly provide my help for the form, but this will for another evening.

[zorun]

Many thanks for the review! I have integrated all your suggestions, and I figured out what was wrong with the form layout.