Resolving the 'NoneType object has no attribute _fields' Error in Odoo 12

Описание: Learn how to fix the '`NoneType` object has no attribute `_fields`' error in Odoo 12 by understanding how to properly use smart records in your custom modules.
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This video is based on the question https://stackoverflow.com/q/62659681/ asked by the user 'Hello_world' ( https://stackoverflow.com/u/11899084/ ) and on the answer https://stackoverflow.com/a/62673413/ provided by the user 'Kenly' ( https://stackoverflow.com/u/5471709/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Understanding the 'NoneType object has no attribute _fields' Error in Odoo 12

As an Odoo developer, you may encounter the error message 'NoneType' object has no attribute '_fields' while working on your custom modules. This issue can arise when you are trying to access fields on a model object that hasn't been properly initialized. In this post, we will delve into the cause of this error and provide a clear, step-by-step solution to fix it.

The Problem

When you attempt to access a field from a model in Odoo, it is crucial to ensure that you are referencing an actual record rather than a NoneType. In your provided code, you have inherited the product.template model to add custom fields. However, the way you are accessing the field in your template seems to be leading to this error.

Example Error

This is the key part of the error message you received:

[[See Video to Reveal this Text or Code Snippet]]

This indicates that the record you are trying to access (in your case the Catimmo class) is not properly defined when the Odoo engine tries to retrieve the field.

Solution Overview

To resolve this issue, you need to ensure that you are using a valid record when attempting to access fields in your Odoo QWeb templates. Here’s how you can effectively implement the solution:

Update Your Template Code

You are currently trying to access the custom field surface using:

[[See Video to Reveal this Text or Code Snippet]]

This code suggests that you are trying to access surface directly from the Catimmo model, which is not a valid approach in this context. Instead, you should refer to the product object that is already available in your template.

Correct Usage

Here’s how to correctly access the surface field from your product object:

[[See Video to Reveal this Text or Code Snippet]]

Revised Code Implementation

Here’s how your updated XML code should look:

[[See Video to Reveal this Text or Code Snippet]]

Explanation of the Change

By changing Catimmo to product, you ensure that the field is being accessed through a proper record. The product variable represents a valid instance of product.template, which contains all associated fields including the ones you have defined in your inherited model.

Conclusion

In summary, the error 'NoneType' object has no attribute '_fields' is commonly encountered when trying to access fields on an uninitialized or unassigned record in Odoo. By ensuring that you are working with valid records and using them correctly in your templates, you can effectively avoid such errors.

Should you continue to encounter issues, always double-check that the model and fields you are trying to access are correctly defined and initialized within the Odoo framework. Happy coding, and good luck with your Odoo projects!