On Tue, 14 Jul 2026 at 10:44, Nyall Dawson <[email protected]> wrote: > > Hi lists, > > Following up the recent formalisation of a process for removal of deprecated > API mid-release cycle (see > https://github.com/qgis/QGIS-Enhancement-Proposals/pull/384), I've just > submitted a proposal to remove the deprecated Python Processing > "WidgetWrapper" API. > > As per clause 1.4.4 of the Stable API policy, this API should be removed on > the grounds that maintaining backward compatibility both introduces an > insurmountable maintenance burden and fundamentally blocks critical bug fixes > (condition 1.4.4.1). > > This pure Python API is an ongoing source of unsolvable issues in the > Processing framework, such as https://github.com/qgis/QGIS/issues/66282. It > relies on a fragile memory management model, where the lifetime of objects > created in C++ vs Python results in unpredictable object deletion or memory > leakage. Over time the conclusion from QGIS developers familiar with this > code is that this approach just cannot be fixed, and we need to move solely > to the approach used elsewhere in QGIS, where Python is used solely to > subclass C++ base classes, with all memory management living at the C++ level > (either through direct C++ memory management or via C++ Qt parent/child > associations). > > In addition, the old API predated major overhauls of Processing GUI > components such as the model designer, and the assumptions used in that API > no longer apply (such as existence of Python dialog classes). Working around > these old assumptions is a considerable drain on QGIS developers, and is > blocking further desirable revamps and modernisation of the QGIS model > designer interface. > > This API has been marked as deprecated since QGIS 3.4, with developer-facing > warnings being shown for over 7 years. > > See https://github.com/qgis/QGIS-Enhancement-Proposals/pull/386 for the > proposed changes and a detailed write up on the plan for removal. > > Please give all feedback on this proposed change as comments on the PR itself > (not direct email replies) to keep the discussion centralized.
This has now passed the two week discussion period and has moved to the voting stage. Kind regards, Nyall _______________________________________________ QGIS-Developer mailing list [email protected] List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
