Base - Write Diff

Summary

This module allows you to update records by filtering out fields whose values are going to be left unchanged by BaseModel.write(); for example, let's assume you have:

>>> self
sale.order.line(1,)
>>> self.price_unit
10.00

If you use self.write({"price_unit": 10.00}) or self.price_unit = 10.00, Odoo may end up executing unnecessary operations, like triggering the update on the field, recompute computed fields that depend on price_unit, and so on, even if the value is actually unchanged.

By using this module, you can prevent all of that.

You can use this module in 3 different ways. All of them require you to add this module as a dependency of your module.

1 - Context key "write_use_diff_values"

By adding write_use_diff_values=True to the context when updating a field value, the BaseModel.write() patch will take care of filtering out the fields' values that are the same as the record's current ones.

⚠️ Beware: the context key is propagated down to other write() calls

Example:

from odoo import models


class ProductTemplate(models.Model):
    _inherit = "product.template"

    def write(self, vals):
        # Update only fields that are actually different
        self = self.with_context(write_use_diff_values=True)
        return super().write(vals)


class ProductProduct(models.Model):
    _inherit = "product.product"

    def update_code_if_necessary(self, code: str):
        # Update ``default_code`` only if different from the current value
        self.with_context(write_use_diff_values=True).default_code = code

2 - Method BaseModel.write_diff()

It is the same as calling write(), but it automatically enables the "write_use_diff_values" context flag: self.write_diff(vals) is a shortcut for self.with_context(write_use_diff_values=True).write(vals)

⚠️ Beware: the context key is propagated down to other write() calls

3 - Method BaseModel._get_write_diff_values(vals)

This method accepts a write-like dict as param, and returns a new dict made of the fields who will actually update the record's values. This allows for a more flexible and customizable behavior than the context key usage, because:

• you'll be able to filter out specific fields, instead of filtering out all the fields whose values won't be changed after the update;
• you'll be able to execute the filtering on specific models, instead of executing it on all the models involved in the stack of write() calls from the first usage of the context key down to the base method BaseModel.write().

Example:

from collections import defaultdict

from odoo import api, models
from odoo.tools.misc import frozendict


class ProductProduct(models.Model):
    _inherit = "product.product"

    def write(self, vals):
        # OVERRIDE: ``odoo.addons.product.models.product_product.Product.write()``
        # override will clear the whole registry cache if either 'active' or
        # 'product_template_attribute_value_ids' are found in the ``vals`` dictionary:
        # remove them unless it's necessary to update them
        fnames = {"active", "product_template_attribute_value_ids"}
        if vals_to_check := {f: vals.pop(f) for f in fnames.intersection(vals)}:
            groups = defaultdict(lambda: self.browse())
            for prod in self:
                groups[frozendict(prod._get_write_diff_values(vals_to_check))] += prod
            for diff_vals, prods in groups.items():
                if res_vals := (vals | dict(diff_vals)):
                    super(ProductProduct, prods).write(res_vals)
            return True
        return super().write(vals)