[Question] account_billing: why is the related invoices button only visible in billed state?

[AungKoKoLin1997]

I’m wondering why this button in the billing form view is only visible in the billed state:

account-invoicing/account_billing/views/account_billing_views.xml

Lines 144 to 156 in 7366a02

	<button
	class="oe_stat_button"
	name="invoice_relate_billing_tree_view"
	type="object"
	invisible="state != 'billed'"
	icon="fa-pencil-square-o"
	>
	<field
	name="invoice_related_count"
	string="Invoices"
	widget="statinfo"
	/>
	</button>

It seems this button could also be useful in the draft state, to allow users to view the related invoices.

@qrtl QT6560

[AungKoKoLin1997]

@Saran440 was there any particular reason for this limitation when this module was originally introduced?
If not, I’d be glad to submit a PR to make it available in the draft state as well.