Dynamic form elements using attributes

So far, we have only looked into changing forms depending on the user’s groups (the groups attribute for elements and the groups_id field for inherited views) and nothing more. This recipe will show you how to modify the form view based on the value of the fields in it.

How to do it...

1. Define an attribute called attributes on a form element:

   <field name="child_ids"
       invisible="not parent_id"
       required="parent_id"/>

2. Ensure that all the fields you refer to are available in your form:

   <field name="parent_id"/>

This will make the child_ids field invisible if the parent_id is not hostel room category, and it will be required if it’s a hostel room category.

How it works...

attributes contains a dictionary with invisible, required, and readonly keys (all of which are optional). The values are domains that may refer to...