Thanks for the clear and candid explanation.

After reviewing the different options, I agree: precomputing and flattening the data is the most reliable approach within Studio’s constraints. I’ll proceed by generating a computed field (or a simple related model with a one2many) to aggregate the component/lot details, then print that in the report via Studio.

Appreciate the guidance — thank you.

— Franck

Hi,

Odoo Studio has strict technical limitations that make it unsuitable for handling complex QWeb loops or deep relational traversals, such as linking delivery lines to manufacturing orders and their component lot numbers. While this type of nested logic (t-foreach="move.production_id.move_raw_ids.mapped('move_line_ids')") works fine in a custom module, Studio’s sandboxed environment blocks such operations for safety and performance reasons. This results in common issues like rendering errors, empty report sections, or RPC errors when trying to display component and lot details directly in a report.

To work around these restrictions, the best approach is to precompute and flatten the data before displaying it. One option is to create a computed text field on the related record (e.g., delivery or invoice line) that aggregates all component and lot details into a readable string such as “Component A (Lot 123), Component B (Lot 456).” This field can be populated through an automated or server action triggered when the manufacturing order is completed. Once the data is stored in a single field, you can easily include it in your report using Studio without any nested loops.

Alternatively, you can create a simple custom model in Studio to store these precomputed component-lot details and link it as a one2many relation to the delivery or invoice record. This allows you to use a single-level t-foreach loop, which Studio supports safely. In summary, since Studio cannot handle deep relational logic inside reports, the most reliable way to display manufacturing component lots on delivery slips or invoices is to prepare the data in advance and store it in a field that can be directly printed.

Hope it helps