.. include:: ../../substitutions.rst QGIS Expression =============== As in QGIS Desktop, Lizmap can use `QGIS expression `_ . Project level ------------- At the project level, Lizmap will set two variables in QGIS Server: * ``@lizmap_user`` : *string*, the current user connected in Lizmap. It might be empty. * ``@lizmap_user_groups`` : *array*, the current user groups as a list. It might be empty. .. note:: It's possible use these variables in a symbology for instance, to set a different color for a given user, or to print the current Lizmap user in a layout. Advanced forms -------------- For editing, it's possible to use expressions for constraints, default value, group visibility. Read :ref:`edition-expressions`. Layouts ------- It's possible to use expressions in layouts, for dates, path of a Lizmap media. In a layout, the expression ``map_credits`` or `more complex expressions `_ are useful.