To implement a custom "Discard" button in Odoo 17 that effectively reverts unsaved changes, you can follow these steps:

1. Define the Discard Button in Your XML View:
   Add a button to your form view with the special="cancel" attribute. This attribute ensures that the button functions as a discard action.

   xml Copy code < footer > 
       < button  string = "Discard"  special = "cancel"  class = "oe_link" /> 
   </ footer >
   

   The special="cancel" attribute is recognized by Odoo to trigger the discard operation, reverting any unsaved changes and closing the form view.
2. Implement the Discard Functionality in Your Python Model:
   If you need to perform additional actions when the discard button is pressed, you can define a method in your model. However, for the standard discard behavior, the special="cancel" attribute handles the necessary operations.

   python Copy code from odoo import models, fields, api
   
   class  YourModel (models.Model):
       _name = 'your.model'
   
       # Define your fields here
   
       @api.multi 
       def  action_discard ( self ):
            # Custom actions before discarding changes 
           self.env.cr.rollback()   # Revert unsaved changes 
           return {
                'type' : 'ir.actions.act_window' ,
                'name' : 'Your Form ' ,
                'res_model' : 'your.model' ,
                'view_mode' : 'form' ,
                'res_id' : self. id ,
                'target' : 'current' ,
           }
   

   In this method, self.env.cr.rollback() is used to discard any uncommitted changes in the current transaction. The returned action reloads the form view without saving the modifications.

Additional Considerations:

• Using special="cancel" : This attribute is a built-in feature in Odoo that provides standard discard functionality without the need for custom methods.
• Custom Discard Logic: If your discard operation requires additional logic, such as resetting specific fields or triggering other actions, you can define a method like action_discard in your model and link it to a button without the special="cancel" attribute.

By following these steps, you can create a custom discard button in Odoo 17 that effectively reverts unsaved changes, ensuring a seamless user experience.

Sources

• self.env.cr.rollback() will discard any changes made in the current transaction.
• This prevents the record from being saved when returning to the form view.

Now, when the action_discard button is clicked, the record’s changes will be discarded and the user will be taken back to the form view without saving any modifications.

Hi! I like yours very much. I think you should check out for some custom dismiss button options. It helps you a lot in this regard.

I did it guys.
I just save each field in the context:

'context': {
    'default_item_id': self.id,
    'default_evaluation_id': evaluation_id,
    'default_item_weight': self.weight,
    'default_date': evaluation.date,
    'default_compliance': evaluation.compliance,
    'default_weight': evaluation.compliance_weight,
    'default_responsible': evaluation.responsible.id,
    'default_observation': evaluation.observation
}

def action_discard(self):
    original_data = {
        'date': self.env.context.get('default_date'),
        'compliance': self.env.context.get('default_compliance'),
        'compliance_weight': self.env.context.get('default_weight'),
        'responsible': self.env.context.get('default_responsible'),
        'observation': self.env.context.get('default_observation')
    }
    self.write(original_data)
    view_id = self.env.ref('sst.view_sst_qualification_form').id
    return {
        'type': 'ir.actions.act_window',
        'name': 'Calificar Items',
        'res_model': 'sst.initial.evaluation.by.cycles',
        'res_id': self.id,
        'view_mode': 'form',
        'views': [[view_id, 'form']],
        'target': 'new',
    }