Support additional files such as SVG symbols

[olivierdalang]

Not sure if this is not yet supported or not documented or if I got something wrong.

I have layers with custom SVG symbols defined with relative paths, like this:

- base directory
  - projects
    - myproject.qgs
  - project_data
    - mydata.geojson
    - images
      - svg1.svg
      - svg2.svg
      - ...

myproject.qgs refers to datasource using ../project_data/mydata.geojson and to svgs using ../project_data/images/svg1.svg.

It works well in QGIS desktop. In G3W suite however, I could not find how to make the SVG symbols available. I thought I could just upload my svg symbols to the shared-volume/project_data with the file upload GUI, like done for datasources, but it doesn't work.

I could make them load by copying my svg symbols to shared-volume/media/project_data, but that's not doable by users through the UI.

Is there a way to achieve this ? Or could this feature be implemented ?

Worth noting that from what I understand, unfortunately the QGIS files get rewritten by g3w-admin to alter the datasource paths. A similar approach would not work for advanced use cases for SVGs (for instance data-defined path to the SVG, that can't just be searched/replaced). I think what is needed is either to be able to upload a project package instead of just a QGIS file (project package being a zipped folder of a QGIS project with arbitrary files), or to document what relative paths structures should be used for projects to be able to access files in shared-volume/media/project_data (I guess it's ../../project_data/myimage.svg)

Is the way QGIS files are rewritten documented somewhere ? Is the structure of the shared-volume directory supposed to be stable in the future (in which case we could just use ../../project_data instead of ../project_data and you could maybe skip rewriting the QGIS file).

Thanks for your inputs !

[Raruto]

Hi @olivierdalang, can you attach a sample file as well? (sometimes it can be worth a thousand words for the final developer 😄)

[wlorenzetti]

Hi @olivierdalang as for QGIS-server standalone you have to set a QGIS3.ini file throug which said to QGIS-server search possible SVG files.

I just push a commit to do that g3w-suite/g3w-suite-docker@1f0163e, now inside config/qgis folder there is a QGIS3.ini file to use:

config/
├── g3w-suite
│   ├── overrides
│   │   ├── static
│   │   └── templates
│   ├── settings_docker_cadastre.py
│   └── settings_docker.py
├── _nginx
│   └── django_ssl.conf
├── nginx
│   └── django.conf
└── qgis
    └── QGIS3.ini

By default in this QGIS3.ini I set the [svg] value :

[svg]
searchPathsForSVG=/usr/share/qgis/svg/, /shared-volume/project_data/svg/

As you can see now you have toi create a folder inside /shared-volume/project_data and put it your SVG files.

This commit at now is on dev branch of g3w-suite-docker repository https://github.com/g3w-suite/g3w-suite-docker/tree/dev.

[olivierdalang]

Ideally I'd like to not alter searchPathsForSVG, because there could be multiple different project using different SVGs with same names, which would result in conflicats (wrong symbol showing in a project).

In QGIS desktop, it's possible to define relative path to SVGs, which works well if you keep your SVG next to your QGIS project file. But such a setup cannot be uploaded to G3W it seems (as QGIS projects are uploaded using a different process than files).

In the mean time I could make it work by using relative paths mimicking the structure in the docker container

root/
├── media
│   └── projects
│       └── myproject.qgs
└── project_data
    ├── data.geojson
    ├── symbol1.svg
    ├── symbol2.svg
    └── symbol3.svg

This way the path to symbols is ../../project_data/symbol1.svg and it seems to work both locally and in G3W-suite.

[wlorenzetti]

@olivierdalang sorry for the delay in the response, I'll add it to documentation thanks.

[Raruto]

Moved in here from g3w-admin while waiting for the documentation to be updated.