# Setting a field 'invisible' conditionnaly only in form view
**URL:** https://discuss.tryton.org/t/setting-a-field-invisible-conditionnaly-only-in-form-view/4186
**Category:** Developer
**Created:** [May 11, 2021, 2:06pm UTC](https://discuss.tryton.org/t/setting-a-field-invisible-conditionnaly-only-in-form-view/4186 "2021-05-11T14:06:26Z")
**Posts on this page:** 12
**Page:** 1
Hi, i’m customizing sale model to allow users to have also a reference field on sale\_lines. I’m doing the same way as the field ‘delivery\_date’ in purchase model.
```auto
class SaleLine(metaclass=PoolMeta):
__name__ = 'sale.line'
reference = fields.Function(fields.Char('Reference',
states={
'invisible': ((Eval('type') != 'line')
| Eval('reference_edit', False)),
},
depends=['type', 'reference_edit']),
'on_change_with_reference')
reference_edit = fields.Boolean(
"Edit Reference",
states={
'invisible': Eval('type') != 'line',
'readonly': Eval('sale_state').in_([
'done', 'cancelled']),
},
depends=['type', 'sale_state'],
help="Check to edit the reference.")
reference_store = fields.Char(
"Reference",
states={
'invisible': ((Eval('type') != 'line')
| ~Eval('reference_edit', False)),
'readonly': Eval('sale_state').in_([
'done', 'cancelled']),
},
depends=['type', 'reference_edit', 'sale_state'])
@classmethod
def default_reference_edit(cls):
return False
@fields.depends('sale', '_parent_sale.reference', 'reference_edit',
'reference_store')
def on_change_with_reference(self, name=None):
if self.reference_edit and self.reference_store:
return self.reference_store
if self.sale:
return self.sale.reference
```
So users can have a reference by default which is sale\_reference in function field ‘reference’, but they could also having a different reference on the sale\_line by checking ‘reference\_edit’ and setting a value in field ‘reference\_store’
A switch is done in the view form to display the correct field (depending if ‘reference\_edit’ is checked or not):
**sale\_line\_form.xml**
```auto
```
Until now everything is working well…
But i want also display that field ‘reference’ in the tree view…
**sale\_line\_tree.xml**
```auto
```
My function field ‘reference’ can display the correct value depending if reference\_edit is checked or not.
But as his state is ‘invisible’ when reference\_edit is checked, the value of ‘reference’ field is not displayed in the tree view…
So, my question:
- Is it possible to have the state ‘invisible’ only in form view ?
- Or should i create another function field ‘reference\_display’ (with the same code as ‘reference’ but without state condition to display this field correctly in the tree view ?
- Another idea ?
Thanks! 🙂
---
We found the same problem when adding the delivery\_date of purchase lines in list view and we solved it adding another field just for displaying as you suggest here:
> [@maxx](#):
>
> Or should i create another function field ‘reference\_display’ (with the same code as ‘reference’ but without state condition to display this field correctly in the tree view ?
For me this make snse because on the list view you want to add another field which is always visible while on the form view you should show/hide two diferent fields depending on the checkbox.
---
I think the invisible state of `reference` should not be defined on the field but on the view (with `ModelView.view_attributes`) in such case because it depends on what is displayed.
The standard `delivery_date` should also be fixed to use `view_attributes`.
---
My bad the `states` attribute on the form view is not supported by the clients. This is probably because it will be ambiguous with `states` of the field.
Maybe another solution would be to add a `setter` to the `Function` field and a `readonly` states when the `edit` field is not checked (and of course for the proper state).
---
> [@ced](#):
>
> My bad the `states` attribute on the form view is not supported by the clients. This is probably because it will be ambiguous with `states` of the field.
However, it seems used in other modules : [https://hg.tryton.org/modules/sale/file/tip/product.py#l94](https://hg.tryton.org/modules/sale/file/tip/product.py#l94)
---
> [@maxx](#):
>
> However, it seems used in other modules : [modules/sale: 0ac079e22786 product.py](https://hg.tryton.org/modules/sale/file/tip/product.py#l94)
This is a `page` widget which is not linked to any field.
---
> [@ced](#):
>
> Maybe another solution would be to add a `setter` to the `Function` field and a `readonly` states when the `edit` field is not checked (and of course for the proper state).
Ok, working this way 🙂 Thanks @ced and @pokoli !
```auto
reference = fields.Function(fields.Char('Reference',
states={
'invisible': Eval('type') != 'line',
'readonly': (Eval('sale_state').in_(['done', 'cancelled'])
| ~Eval('reference_edit')),
},
depends=['type', 'reference_edit', 'sale_state']),
'on_change_with_reference', setter='set_reference_field')
reference_edit = fields.Boolean(
"Edit Reference",
states={
'invisible': Eval('type') != 'line',
'readonly': Eval('sale_state').in_([
'done', 'cancelled']),
},
depends=['type', 'sale_state'],
help="Check to edit the reference.")
reference_store = fields.Char(
"Reference",
states={
'readonly': Eval('sale_state').in_([
'done', 'cancelled']),
},
depends=['sale_state'])
@classmethod
def default_reference_edit(cls):
return False
@fields.depends('sale', '_parent_sale.reference', 'reference_edit',
'reference_store')
def on_change_with_reference(self, name=None):
if self.reference_edit and self.reference_store:
return self.reference_store
if self.sale:
return self.sale.reference
@classmethod
def set_reference_field(cls, lines, name, value):
if not value:
return
cls.write(lines, {
'reference_store': value,
})
```
sale\_line\_form.xml
```auto
```
---
I think it could be simplified using a functional also for _reference\_edit_ field, don’t you? It’s value would be _True_ when _reference\_store_ had some value, and _False_ otherwise. It would have a _setter_ that would copy the value from _reference_ to _reference\_store_ when checked and reset it if unchecked.
---