How to carry data from one form to another in odoo 11? - action

Question

I have three models.
class student(models.Model):
_name = 'student.info'
_description = 'Students\' Information'
name = fields.Char('Name', required=True)
age = fields.Integer('Age', compute='_compute_age', store=True)
date_of_birth = fields.Date('Date of Birth', required=True)
teacher_id = fields.Many2one('teacher.info', 'Teacher')
class teacher(models.Model):
_name = 'teacher.info'
_description = 'Teachers\' Information'
name = fields.Char('Name', required=True)
position = fields.Char('Position')
section_id = fields.Many2one('stu.section', 'Section')
student_ids = fields.Many2many('student.info', 'student_teacher_rel', 'teacher_id', 'student_id', 'Students')
class section(models.Model):
_name = 'stu.section'
_description = 'Students\' Sections'
name = fields.Char('Name', required=True)
student_ids = fields.Many2many('student.info', 'student_section_rel', 'section_id', 'student_id')
two actions,
<record id="action_student_to_class" model="ir.actions.act_window">
<field name="name">Class</field>
<field name="res_model">stu.section</field>
<field name="view_type">form</field>
<field name="view_mode">form</field>
<field name="context">{'default_student_ids' : [(4, active_id)]}</field>
</record>
<record id="action_class_to_teacher" model="ir.actions.act_window">
<field name="name">Class</field>
<field name="res_model">teacher.info</field>
<field name="view_type">form</field>
<field name="view_mode">form</field>
<field name="context">{
'default_student_ids' : active_id.student_ids,
'default_section_id' : active_id,
}</field>
</record>
and two buttons. One in student form view and the other in section form view.
<button name="%(action_student_to_class)d"
type="action"
string="To Class"
class="oe_highlight"/>
<button name="%(action_student_to_class)d"
type="action"
string="To Class"
class="oe_highlight"/>
When 'To Class' button is clicked from student form, the action updates the current student in the section student_ids. But when 'To Teacher' button is clicked from section form, I want to update both the current section and student_ids in section in the teacher form. I have done this by returning action from python, but I want to do this from xml? How can I achieve this? Thanks.

Answer 1

I have found the solution.
It's okay if we don't add context in action for the button. We can add context in button like
<button name="%(action_student_to_class)d"
type="action"
string="To Class"
class="oe_highlight"
context="{'default_student_ids' : student_ids, 'default_section_id' : active_id}"/>