interactive_map_tracking
A QGIS 2.6 plugin to track camera of user , AND/OR to autocommit/refresh edit on PostGIS vector layer
This QGIS 2.6 plug-in has been developed by Lionel Atty from IGN (France).
Go to the project wiki for more information !
This plug-in was designed to allow concurrent editing awareness or history of editing (tracking), and to enable QGIS to play well with PostGIS database using trigger to reconstruct geometry on the fly
feature
This plug-in add 2 features to QGIS, the user choose what feature he uses
You can see a short video of demos :
tracking the position
- each time the user change its position on QGIS map canvas, the screen rectangle is saved along with a user id and a timestamp. That is, if the user zoom level is compatible with edition (parameter)
- with correct QGIS styling, this enable to see :
- where the other users are editing so two people won't hopefully edit the same area
- where the other users (and self) were editing, so an user won't come and edit the same area twice
- Moreover, this tracking data can be analysed to produce :
- a map of editing time (gives the place where editing was short/long)
- Reliable stats on editing time and area edited per user, which is essential in a benchmark
autosave and refresh after an edit
- QGIS uses a sophisticated Do/Undo mechanism with a delayed writing system. However, when working with a data base that generates geometry on the fly (trigger), it is essential to commit each change immediately.
- The plug-in does exactly that : each modification (geometry or attribute) is saved immediately to the layer, and the canvas is re-rendered.
- this instantaneous commit allow to create new user interaction that are within the database, as opposed to be within QGIS. Thus, this interactions can be used in other GIS software, and can be much more complex.
This work was partly supported by Agence Nationale de la Recherche Grant ANR-12-VBDU-0002-09 (TrafiPollu project), and by Thales Training & Simulation SAS within FUI project TerraMobilita. The result of this works is under the co-property of IGN and Thales Training & Simulation SAS