I'm using QGIS. I have one qml-file which I apply to many layers of different projects (so all gas-pipes have the same style). As for now, I can make a change to that qml, save it and than I have to go through all projects which contain a gas layer relying on that qml and manually load that updated qml. Is there a way to apply changes to that qml and all gas-pipe layers in all different projects get this updated style automatically?
If using shapefile (the gas-pipes are stored in shapefiles): Give the qml-file the same name as the shapefile and QGIS will use that stylefile automatically when loading the shapefile.
Example: You change the appearance (style) of gas-pipe.shp and save the style to gas-pipe.qml. You have 2 other shapefiles for other gas-pipes, let's say their filenames are gas-pipe_wall.shp and gas-pipe_roof.shp. Copy gas-pipe.qml to gas-pipe_wall.qml and to gas-pipe_roof.qml. The next time you open a QGIS-project using gas-pipe_wall.shp and gas-pipe_roof.shp, these gas-pipe-files will be displayed in the same way as gas-pipe.shp.
You may automate the copying and renaming of the qml-file with a batch-file (*.bat) if you work on Windows.