QField 3.4 is out, and it won’t disappoint. It has tons of new features that continue to push the limits of what users can do in the field.

Main highlights

A new geofencing framework has landed, enabling users to configure QField behaviors in relation to geofenced areas and user positioning. Geofenced areas are defined at the project-level and shaped by polygons from a chosen vector layer. The three available geofencing behaviours in this new release are:

• Alert user when inside an area polygon;
• Alert user when outside all defined area polygons and
• Inform the user when entering and leaving an area polygons.

In addition to being alerted or informed, users can also prevent digitizing of features when being alerted by the first or second behaviour. The configuration of this functionality is done in QGIS using QFieldSync.

Pro tip: geofencing settings are embedded within projects, which means it is easy to deploy these constraints to a team of field workers through QFieldCloud. Thanks Terrex Seismic for sponsoring this functionality.

QField now offers users access to a brand new processing toolbox containing over a dozen algorithms for manipulating digitized geometries directly in the field. As with many parts of QField, this feature relies on QGIS’ core library, namely its processing framework and the numerous, well-maintained algorithms it comes with.

The algorithms exposed in QField unlock many useful functionalities for refining geometries, including orthogonalization, smoothing, buffering, rotation, affine transformation, etc. As users configure algorithms’ parameters, a grey preview of the output will be visible as an overlay on top of the map canvas.

To reach the processing toolbox in QField, select one or more features by long-pressing on them in the features list, open the 3-dot menu and click on the process selected feature(s) action. Are you excited about this one? Send your thanks to the National Land Survey of Finland, who’s support made this a reality.

QField’s camera has gained support for customized ratio and resolution of photos, as well as the ability to stamp details – date and time as well as location details - onto captured photos. In fact, QField’s own camera has received so much attention in the last few releases that we have decided to make it the default one. On supported platforms, users can switch to their OS camera by disabling the native camera option found at the bottom of the QField settings’ general tab.

Wait, there’s more

There are plenty more improvements packed into this release from project variables editing using a revamped variables editor through to integration of QField documentation help in the search bar and the ability to search cloud project lists. Read the full 3.4 changelog to know more, and enjoy the release!

Sorry, this entry is only available in French.

Sorry, this entry is only available in French.

Statistiche su punti sovrapposti

Introduzione

Ho un file vettore di punti molti dei quali sono sovrapposti. come creare una etichetta che mostri il valore massimo, minimo o medio di un campo, calcolandolo ovviamente solo per i punti sovrapposti.

!!! Abstract "Array_agg" Restituisce un array di valori aggregati da un campo o espressione.

Mappa valori generata al volo

Introduzione

Come generare, in un form, un menu a tendina popolato con valori recuperati, al volo, da altro layer.

!!! Abstract "current_value" all'interno di un form restituisce il valore corrente non salvato di un campo nel modulo o nella riga della tabella attualmente in fase di modifica. Questo differirà dai valori effettivo dell'attributo dell'elemento per gli elementi che sono attualmente in fase di modifica o che non sono ancora state aggiunte ad un layer.

QField Rapid Mapper is a project for the QField mobile app, which allows emergency responders, civil protection, military, and citizens to assess and report damages from natural catastrophes by quickly sharing geolocated images, videos and audio. QField Rapid Mapper offers real-time data collection, mapping and sharing to help enhance disaster response and coordination.
QField and QFieldCloud are open-source, and OPENGIS.ch is donating the needed QFieldCloud infrastructure and expertise to help map the floods in Ticino in 2024

Join the effort

OPENGIS.ch Supports Flood Mapping Efforts in Ticino

After discussing with the Protezione Civile Locarno e Valle Maggia and the Centro di Competenza per la geoinformazione (CCGEO), we are proud to announce that OPENGIS.ch is donating the necessary QFieldCloud infrastructure and dedicated projects for a rapid crowdsourcing POC to aid in mapping the 2024 floods in Ticino. This crowdsourcing initiative aims to provide essential support to professionals and volunteers working on flood and landslide assessment and recovery.

https://www.rsi.ch/play/embed?urn=urn:rsi:video:2191880&subdivisions=false

Empowering Response with Advanced Technology

What is needed?

Photographing damaged houses and infrastructure is the most critical aspect of this mapping initiative. These images provide crucial information for assessing the extent of the damage, planning rescue and reconstruction operations, and ensuring that resources are allocated effectively. It’s also important to document any submerged or damaged vehicles, as they offer additional insights into the disaster’s impact. During these activities, it’s essential to be careful and respect the privacy and property of others, avoiding capturing license plate numbers or entering destroyed buildings without permission. Using QField Rapid Mapper can contribute to a faster and more coordinated emergency response while ensuring respect for those affected.

The QFieldCloud infrastructure enables efficient, real-time data collection and sharing, ensuring that accurate and up-to-date information is available to all stakeholders involved in the flood response. This effort underscores our commitment to leveraging technology for social good and environmental resilience.

How You Can Get Involved

1. if you don’t have a QFieldCloud account yet, sign up at https://app.qfield.cloud/accounts/signup/
2. fill out the quick participation form at https://forms.gle/dkjZsSWdmCzr9xic8

By participating, you will have access to powerful tools for field data collection and can contribute valuable information to the ongoing efforts in Ticino. All the data collected will be released under the Creative Commons CC0 1.0 public domain license.

Join the Effort

Using QField and QFieldCloud, you can help create detailed maps crucial for understanding the impact of the floods and planning effective recovery strategies. Your contributions will make a significant difference in managing and mitigating the effects of this natural disaster.

Join the effort

Visit our QField Rapid Mapper project page for more information on how QField and QFieldCloud can assist in flood mapping and other field data collection projects.

Together, we can make a difference. Join us in mapping the floods in Ticino and support the community’s recovery efforts.

This blog post will introduce QField’s brand new plugin framework and walk through the creation of a plugin to support bird watchers in need of a quick way to digitize photos of spotted birds onto a point vector layer.

A plugin framework is born!

As announced recently, QField now empowers users through a brand new plugin framework allowing for simple customization on the way the application behaves or looks all the way through to creating completely new functionalities.

The plugin framework relies on Qt’s QML engine and JavaScript, allowing for cross-platform support out of the box. This means that plugins will run perfectly fine on all platforms currently supported by QField: Android, iOS, Windows, Linux, and macOS.

App-wide plugin vs. project plugin

First, let’s look at the two types of plugins supported by QField: app-wide plugins and project plugins. As their names imply, the main difference is their scope. An enabled app-wide plugin will remain active as long as QField is running, while project plugins are activated on project load and deactivated when the project tied to the plugin is closed.

Project plugins are shipped alongside a given project file ( .qgs/ .qgz). Project plugins must share the same name of the project file with a .qml extension. For example, if your project file is birdwatcher.qgz, QField will look for the presence of a birdwatcher.qml to activate the project plugin. For app-wide plugins, installation is done via the plugins manager popup; more on this below.

Distribution of project plugins can be greatly facilitated through QFieldCloud. The presence of project plugins within a cloud project environment will be automatically detected and packaged alongside the project file and its datasets when deployed to QField devices.

Starting with a project plugin

We will start with looking into a simple project plugin that offers a new digitizing mechanism focused on snapping photos as a trigger for point feature addition. This plugin will demonstrate how new functionalities and behaviors can be added to QField to serve specific needs. In this case, the new digitizing mechanism could come in handy for bird watchers and other users in need of a quick way to snap photos!

It’s advised to download a version of QField running on your desktop environment while testing plugins. Links to Windows, Linux, and macOS builds are available here. Once installed, download this project archive containing a tiny birdwatcher sample project and extract it into a new directory on your local machine.

The project archive consists of a point vector layer ( observations.gpkg), a project file ( birdwatcher.qgz) as well as a project plugin ( birdwatcher.qml) which we will look into below. Please note that the point vector layer’s attribute form is already configured to display captured photos. We will not spend time on attribute form setup in this post; see this relevant documentation page if you are interested in knowing how that was achieved.

We can now test the project plugin by opening the project ( birdwatcher.qgz) in QField. Users familiar with QField will notice a new ‘camera’ tool button present on the top-right corner of the map canvas. This button was added by the project plugin. You can press on it, to open the QField camera, take a photo (of yourself, a random object on your table, or with a bit of luck a bird), and witness how that leads to a point feature creation.

Digging into the project plugin file

Let’s open the project plugin file (birdwatcher.qml) in your favorite text editor. The first few lines define the QML imports needed by the plugin:

import QtQuick
import QtQuick.Controls

import org.qfield
import org.qgis
import Theme

import "qrc:/qml" as QFieldItems

Beyond the two QtQuick imports, we will make use of QField-specific types and items as well as QGIS ones ( registered and declared in this source file), a Theme to retrieve icons and colors as well as QField items such as tool buttons ( see this source directory), as well as the QField QML items embedded into the application itself to make use of the camera.

The next line declares an generic Item component which will be used by QField to initiate the plugin. This must be present in all plugins. As this plugin does, you can use the Component.onCompleted signal to trigger code execution. In this case, we are using iface to add a tool button on top of the map canvas:

Component.onCompleted: {
  iface.addItemToPluginsToolbar(snapButton)
}

Just above these lines, the plugin declare a number of properties pointing to items found in the main QField ApplicationWindow:

property var mainWindow: iface.mainWindow()
property var positionSource: iface.findItemByObjectName('positionSource')
property var dashBoard: iface.findItemByObjectName('dashBoard')
property var overlayFeatureFormDrawer: iface.findItemByObjectName('overlayFeatureFormDrawer')

Users can reach through to any items within QField’s ApplicationWindow provided they have an objectName property defined. The string value is used in the iface.findItemByObjectName() function to retrieve the item.

The rest of the file consists of a loader to activate the QField camera, a tool button to snap a photo, and a function to create a new feature within which the current position is used as geometry and the snapped photo is attached to the feature form.

The function itself provides a good example of what can be achieved by using the parts of QGIS exposed through QML, as well as utility functions and user interface provided by QField:

function snap(path) {
  let today = new Date()
  let relativePath = 'DCIM/' + today.getFullYear()
                              + (today.getMonth() +1 ).toString().padStart(2,0)
                              + today.getDate().toString().padStart(2,0)
                              + today.getHours().toString().padStart(2,0)
                              + today.getMinutes().toString().padStart(2,0)
                              + today.getSeconds().toString().padStart(2,0)
                              + '.' + FileUtils.fileSuffix(path)
  platformUtilities.renameFile(path, qgisProject.homePath + '/' + relativePath)

  let pos = positionSource.projectedPosition
  let wkt = 'POINT(' + pos.x + ' ' + pos.y + ')'

  let geometry = GeometryUtils.createGeometryFromWkt(wkt)
  let feature = FeatureUtils.createFeature(dashBoard.activeLayer, geometry)

  let fieldNames = feature.fields.names
  if (fieldNames.indexOf('photo') > -1) {
    feature.setAttribute(fieldNames.indexOf('photo'), relativePath)
  } else if (fieldNames.indexOf('picture') > -1) {
    feature.setAttribute(fieldNames.indexOf('picture'), relativePath)
  }

  overlayFeatureFormDrawer.featureModel.feature = feature
  overlayFeatureFormDrawer.state = 'Add'
  overlayFeatureFormDrawer.open()
}

The QGIS API Documentation site is a good resource for learning what parts of the many QGIS classes are exposed to QML. For example, the QgsFeature documentation page contains a Properties section and a Q_INVOKABLE prefix next to functions indicating their availability within a QML/JavaScript environment.

Deployment of a project plugin via QFieldCloud

As mentioned above, QFieldCloud greatly eases the deployment of project plugins to devices in the field. We will now go through the steps required to create a cloud project environment based on the birdwatcher sample project, and witness it handling the project plugin automatically.

This will require you to registered for a freely available QFieldCloud community account if you haven’t done so yet ( it takes a minute to do so, what are you waiting for ;) ). We will also need the QFieldSync plugin in QGIS, which can be enabled through the QGIS plugin manager.

Let’s open QGIS, and log into QFieldCloud by clicking on the QFieldSync toolbar’s blue cloud icon. Once logged in, click on the ‘Create New Project’ tool button found at the bottom of the dialog.

In the subsequent panel dialog, choose the ‘Create a new empty QFieldCloud project’ and then hit the ‘Next’ button. Give it a name and a description, and for the local directory, pick the folder within which you had extracted the birdwatcher project, then hit the ‘Create’ button.

QFieldSync will then ask you to upload your newly created cloud project environment to the server. Notice how the project plugin file (birdwatcher.qml) is part of the files to be delivered to the cloud. Confirm by clicking on the ‘Upload to server’ button.

When QFieldSync is finished uploading, you are ready to take your mobile device, open QField, log into your QFieldCloud account and download the cloud project. Once the cloud project is loaded, you will be asked for permission to load the project plugin, which you can grant on a permanent or one-time basis.

Bravo! You have successfully deployed a project plugin through QFieldCloud.

Creating an app-wide plugin directory

Let’s move on to creating a functional app-wide plugin directory. Download this sample app-wide plugin and extract it into a new directory placed in the ‘plugins’ directory, itself found within the QField app directory. The location of the app directory is provided in the ‘About QField’ overlay, take note of it prior to extracting the plugin if you have not done so yet.

As seen in the screenshot above, which demonstrates the directory hierarchy, a given plugin directory must contain at least two files: a main.qml file, which QField will use to activate the plugin, and a metadata.txt file containing basic information on the plugin, such as the plugin name, author details, and version.

Here’s a sample metadata.txt from the birdwatcher project plugin upgraded into an app-wide plugin:

[general]
name=Snap!
description=Digitize points through snapping photos
author=OPENGIS.ch
icon=icon.svg
version=1.0
homepage=/

Opening main.qml in your favourite text editor will reveal that it has the exact same content as the above-shared project plugin. The only change is the renaming of birdwatcher.qml to main.qml to take into account this plugin’s app-wide scope.

PSA: we have setup this GitHub QField template plugin repository to ease creation of plugins. Fork at will!

Deploying app-wide plugins

While currently not as smooth as deploying a project plugin through QFieldCloud, app-wide plugins can be installed onto devices using a URL pointing to a zipped archive file containing the content of a given plugin directory. The zipped archive file can then be hosted on your own website, on a GitHub or GitLab repository, a Dropbox link, etc.

In QField, open the plugins manager popup found in the settings panel, and use the ‘Install plugin from URL’ button to paste a URL pointing to a zipped plugin file.

You should keep the zipped archive file name consistent for a better user experience, as it is used to determine the installation directory. This is an important consideration to take into account when offering plugin updates. If your zipped plugin file name changes, the plugin will not be updated but rather added to a new directory alongside the previously installed plugin.

QField does allow for a version tag to be added to a zipped archive file name, provided it is appended at the end of the file name, preceded by a dash, and includes only numbers and dots. For example, myplugin-0.0.1.zip and myplugin-0.2.1.zip will install the plugin in the myplugin directory.

Empowering users as well as developers

Here at OPENGIS.ch, we believe this new plugin framework empowers not only users but also developers, including our very own ninjas! With plugin support, we now have the possibility to develop answers to specific field scenarios that would not necessarily be fit for QField-wide functionalities. We would love to hear your opinion and ideas.

If you would like to supercharge your fieldwork and need some help, do not hesitate to contact us - your projects are our passion 💚

P.S. If you are developing a cool QField plugin, also let us know! :)

Bird SVG in video CC-BY https://svgrepo.com/svg/417419/bird