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(Fr) En direct des Journées Utilisateurs QGIS-fr !

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(Fr) [Témoignage client] Émilie Bigorne, géomaticienne EPTB Loire

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Software quality in QGIS

According to the definition of software quality given by french Wikipedia

An overall assessment of quality takes into account external factors, directly observable by the user, as well as internal factors, observable by engineers during code reviews or maintenance work.

I have chosen in this article to only talk about the latter. The quality of software and more precisely QGIS is therefore not limited to what is described here. There is still much to say about:

  • Taking user feedback into account,
  • the documentation writing process,
  • translation management,
  • interoperability through the implementation of standards,
  • the extensibility using API,
  • the reversibility and resilience of the open source model…

These are subjects that we care a lot and deserve their own article.

I will focus here on the following issue: QGIS is free software and allows anyone with the necessary skills to modify the software. But how can we ensure that the multiple proposals for modifications to the software contribute to its improvement and do not harm its future maintenance?


All developers contributing to QGIS code doesn’t belong to the same organization. They don’t all live in the same country, don’t necessarily have the same culture and don’t necessarily share the same interests or ambitions for the software. However, they share the awareness of modifying a common good and the desire to take care of it.

This awareness transcends professional awareness, the developer not only has a responsibility towards his employer, but also towards the entire community of users and contributors to the software.

This self-discipline is the foundation of the quality of the contributions of software like QGIS.

However, to err is human and it is essential to carry out checks for each modification proposal.

Automatic checks

With each modification proposal (called Pull Request or Merge Request), the QGIS GitHub platform automatically launches a set of automatic checks.

Example of proposed modification

Result of automatic checks on a modification proposal

The first of these checks is to build QGIS on the different systems on which it is distributed (Linux, Windows, MacOS) by integrating the proposed modification. It is inconceivable to integrate a modification that would prevent the application from being built on one of these systems.

The tests

The first problem posed by a proposed modification is the following “How can we be sure that what is going to be introduced does not break what already exists?”

To validate this assertion, we rely on automatic tests. This is a set of micro-programs called tests, which only purpose is to validate that part of the application behaves as expected. For example, there is a test which validates that when the user adds an entry in a data layer, then this entry is then present in the data layer. If a modification were to break this behavior, then the test would fail and the proposal would be rejected (or more likely corrected).

This makes it possible in particular to avoid regressions (they are very often called non-regression tests) and also to qualify the expected behavior.

There are approximately 1.3 Million lines of code for the QGIS application and 420K lines of test code, a ratio of 1 to 3. The presence of tests is mandatory for adding functionality, therefore the quantity of test code increases with the quantity of application code.

In blue the number of lines of code in QGIS, in red the number of lines of tests

There are currently over 900 groups of automatic tests in QGIS, most of which run in less than 2 seconds, for a total execution time of around 30 minutes.

We also see that certain parts of the QGIS code – the most recent – are better covered by the tests than other older ones. Developers are gradually working to improve this situation to reduce technical debt.

Code checks

Analogous to using a spell checker when writing a document, we carry out a set of quality checks on the source code. We check, for example, that the proposed modification does not contain misspelled words or “banned” words, that the API documentation has been correctly written or that the modified code respects certain formal rules of the programming language.

We recently had the opportunity to add a check based on the clang-tidy tool. The latter relies on the Clang compiler. It is capable of detecting programming errors by carrying out a static analysis of the code.

Clang-tidy is, for example, capable of detecting “narrowing conversions”.

Example of detecting “narrowing conversions”

In the example above, Clang-tidy detects that there has been a “narrowing conversion” and that the value of the port used in the network proxy configuration “may” be corrupted. In this case, this problem was reported on the QGIS issues platform and had to be corrected.

At that time, clang-tidy was not in place. Its use would have made it possible to avoid this anomaly and all the steps which led to its correction (exhaustive description of the issue, multiple exchanges to be able to reproduce it, investigation, correction, review of the modification), meaning a significant amount of human time which could thus have been avoided.

Peer review

A proposed modification that would validate all of the automatic checks described above would not necessarily be integrated into the QGIS code automatically. In fact, its code may be poorly designed or the modification poorly thought out. The relevance of the functionality may be doubtful, or duplicated with another. The integration of the modification would therefore potentially cause a burden for the people in charge of the corrective or evolutionary maintenance of the software.

It is therefore essential to include a human review in the process of accepting a modification.

This is more of a rereading of the substance of the proposal than of the form. For the latter, we favor the automatic checks described above in order to simplify the review process.

Therefore, human proofreading takes time, and this effort is growing with the quantity of modifications proposed in the QGIS code. The question of its funding arises, and discussions are in progress. The association notably dedicates a significant part of its budget to fund code reviews.

More than 100 modification proposals were reviewed and integrated during the month of December 2023. More than 30 different people contributed. More than 2000 files have been modified.

Therefore the wait for a proofreading can sometimes be long. It is also often the moment when disagreements are expressed. It is therefore a phase which can prove frustrating for contributors, but it is an important and rich moment in the community life of a free project.

To be continued !

As a core QGIS developer, and as a pure player OpenSource company, we believe it is fundamental to be involved in each step of the contribution process.

We are investing in the review process, improving automatic checks, and in the QGIS quality process in general. And we will continue to invest in these topics in order to help make QGIS a long-lasting and stable software.

If you would like to contribute or simply learn more about QGIS, do not hesitate to contact us at [email protected] and consult our QGIS support proposal.

(Fr) Rencontres QGIS-fr – Grenoble 27 & 28 mars 2024

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QField 3.0 release : field mapping app, based on QGIS

We are very happy and enthusiasts at Oslandia to forward the QField 3.0 release announcement, the new major update of this mobile GIS application based on QGIS.

Oslandia is a strategic partner of, the company at the heart of QField development, as well as the QFieldCloud associated SaaS offering. We join to announce all the new features of QField 3.0.

Get QField 3.0 now !

QField 3.0 screenshots


Shipped with many new features and built with the latest generation of Qt’s cross-platform framework, this new chapter marks an important milestone for the most powerful open-source field GIS solution.

Main highlights

Upon launching this new version of QField, users will be greeted by a revamped recent projects list featuring shiny map canvas thumbnails. While this is one of the most obvious UI improvements, countless interface tweaks and harmonization have occurred. From the refreshed dark theme to the further polishing of countless widgets, QField has never looked and felt better.

The top search bar has a new functionality that allows users to look for features within the currently active vector layer by matching any of its attributes against a given search term. Users can also refine their searches by specifying a specific attribute. The new functionality can be triggered by typing the ‘f’ prefix in the search bar followed by a string or number to retrieve a list of matching features. When expanding it, a new list of functionalities appears to help users discover all of the tools available within the search bar.

QField’s tracking has also received some love. A new erroneous distance safeguard setting has been added, which, when enabled, will dictate the tracker not to add a new vertex if the distance between it and the previously added vertex is greater than a user-specified value. This aims at preventing “spikes” of poor position readings during a tracking session. QField is now also capable of resuming a tracking session after being stopped. When resuming, tracking will reuse the last feature used when first starting, allowing sessions interrupted by battery loss or momentary pause to be continued on a single line or polygon geometry.

On the feature form front, QField has gained support for feature form text widgets, a new read-only type introduced in QGIS 3.30, which allows users to create expression-based text labels within complex feature form configurations. In addition, relationship-related form widgets now allow for zooming to children/parent features within the form itself.

To enhance digitizing work in the field, QField now makes it possible to turn snapping on and off through a new snapping button on top of the map canvas when in digitizing mode. When a project has enabled advanced snapping, the dashboard’s legend item now showcases snapping badges, allowing users to toggle snapping for individual vector layers.

In addition, digitizing lines and polygons by using the volume up/down hardware keys on devices such as smartphones is now possible. This can come in handy when digitizing data in harsh conditions where gloves can make it harder to use a touch screen.

While we had to play favorites in describing some of the new functionalities in QField, we’ve barely touched the surface of this feature-packed release. Other major additions include support for Near-Field Communication (NFC) text tag reading and a new geometry editor’s eraser tool to delete part of lines and polygons as you would with a pencil sketch using an eraser.

Thanks to Deutsches Archäologisches Institut, Groupements forestiers Québec, Amsa, and Kanton Luzern for sponsoring these enhancements.

Quality of life improvements

Starting with this new version, the scale bar overlay will now respect projects’ distance measurement units, allowing for scale bars in imperial and nautical units.

QField now offers a rendering quality setting which, at the cost of a slightly reduced visual quality, results in faster rendering speeds and lower memory usage. This can be a lifesaver for older devices having difficulty handling large projects and helps save battery life.

Vector tile layer support has been improved with the automated download of missing fonts and the possibility of toggling label visibility. This pair of changes makes this resolution-independent layer type much more appealing.

On iOS, layouts are now printed by QField as PDF documents instead of images. While this was the case for other platforms, it only became possible on iOS recently after work done by one of our ninjas in QGIS itself.

Many thanks to DB Fahrwgdienste for sponsoring stabilization efforts and fixes during this development cycle.

Qt 6, the latest generation of the cross-platform framework powering QField

Last but not least, QField 3.0 is now built against Qt 6. This is a significant technological milestone for the project as this means we can fully leverage the latest technological innovations into this cross-platform framework that has been powering QField since day one.

On top of the new possibilities, QField benefited from years of fixes and improvements, including better integration with Android and iOS platforms. In addition, the positioning framework in Qt 6 has been improved with awareness of the newer GNSS constellations that have emerged over the last decade.

Forest-themed release names

Forests are critical in climate regulation, biodiversity preservation, and economic sustainability. Beginning with QField 3.0 “Amazonia” and throughout the 3.X’s life cycle, we will choose forest names to underscore the importance of and advocate for global forest conservation.

Software with service and Oslandia provides the full range of services around QField and QGIS : training, consulting, adaptation, specific development and core development, maintenance and assistance. Do not hesitate to contact us and detail your needs, we will be happy to collaborate : [email protected]

As always, we hope you enjoy this new release. Happy field mapping!

Strategic partnership agreement between Oslandia and on QField

Who are we?

🤔 For those unfamiliar with Oslandia,, or even QGIS, let’s refresh your memory:

👉 Oslandia is a French company specializing in open-source Geographic Information Systems (GIS). Since our establishment in 2009, we have been providing consulting, development, and training services in GIS, with reknown expertise. Oslandia is a dedicated open-source player and the largest contributor to the QGIS solution in France.

👉 As for, they are a Swiss company specializing in the development of open-source GIS software. Founded in 2011, is the largest Swiss contributor to QGIS. is the creator of QField, the most widely used open-source mobile GIS solution for geomatics professionals. also offers QFieldCloud as a SaaS or on-premise solution for collaborative field project management.

😲 Some may still be unfamiliar with #QGIS ?

It is a free and open-source Geographic Information System that allows creating, editing, visualizing, analyzing, and publicating geospatial data. QGIS is a cross-platform software that can be used on desktops, servers, as a web application, or as a development library.

QGIS is open-source software developed by multiple contributors worldwide. It is an official project of the OpenSource Geospatial Foundation (OSGeo) and is supported by the association. See

A Partnership?

🎉 Today, we are delighted to announce our strategic partnership aimed at strengthening and promoting QField, the mobile application companion of QGIS Desktop.

🌟 This partnership between Oslandia and is a significant step for QField and open-source mobile GIS solutions. It will consolidate the platform, providing users worldwide with simplified access to effective tools for collecting, managing, and analyzing geospatial data in the field.

📱 QField, developed by, is an advanced open-source mobile application that enables GIS professionals to work efficiently in the field, using interactive maps, collecting real-time data, and managing complex geospatial projects on Android, iOS, or Windows mobile devices.

↔ QField is cross-platform, based on the QGIS engine, facilitating seamless project sharing between desktop, mobile, and web applications.

🕸 QFieldCloud (, the collaborative web platform for QField project management, will also benefit from this partnership and will be enhanced to complement the range of tools within the QGIS platform.


❤ At Oslandia, we are thrilled to collaborate with on QGIS technologies. Oslandia shares with a common vision of open-source software development: a strong involvement in development communities, work in respect with the ecosystem, an highly skilled expertise, and a commitment to industrial-quality, robust, and sustainable software development.

👩‍💻 With this partnership, we aim to offer our clients the highest expertise across all software components of the QGIS platform, from data capture to dissemination.

🤝 On the side, Marco Bernasocchi adds:

The partnership with Oslandia represents a crucial step in our mission to provide leading mobile GIS tools with a genuine OpenSource credo. The complementarity of our skills will accelerate the development of QField and QFieldCloud and meet the growing needs of our users.

Commitment to open source

🙏 Both companies are committed to continue supporting and improving QField and QFieldCloud as open-source projects, ensuring universal access to this high-quality mobile GIS solution without vendor dependencies.

Ready for field mapping ?

🌏 And now, are you ready for the field?

So, download QField (, create projects in QGIS, and share them on QFieldCloud!

✉ If you need training, support, maintenance, deployment, or specific feature development on these platforms, don’t hesitate to contact us. You will have access to the best experts available: [email protected].


(Fr) Oslandia recrute : Ingénieur(e) développement d’applications SIG ( Python / SQL / QGIS ) – OSL2110A

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(Fr) QSoccer : QGIS, football, what else ?

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(Fr) Oslandia recrute : ingénieur(e) développement C++ / Python – OSL2011B

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(Fr) Entretien avec Vincent Picavet

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(Fr) Oslandia recrute : Ingénieur(e) développement d’applications SIG ( Python / SQL / QGIS )

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(Fr) Rechercher une adresse avec QGIS

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(Fr) Oslandia recrute : développeur(se) C++ et Python

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Nouvel outil d’édition des géométries dans QGIS : tronquer/prolonger

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