Reports without changing anything, the shape rfp_project_audit() uses. A
provider subset is the SQL WHERE clause the OGR provider applies to a
layer - what makes one layer show only the coho where another over the same
table shows everything.
Value
With layer, the subset as a string, or NA_character_ when the
layer has none. Without, a data frame of layer, id, subset and
agrees - one row per <maplayer>, filtered to those carrying a subset.
Details
Reading is deliberately permissive: it returns whatever the project has,
including the double-quoted-literal form that rfp_qgs_subset_set()
refuses. A reader that refused what the fleet contains could not report on
it.
agrees answers whether the layer's two datasource surfaces carry the same
filter. They routinely differ in the path - a tree entry keeps the
authoring machine's absolute path where the maplayer has a project-relative
one, in 48 of 54 layers in one shipped template - so only the subset=
option is compared, and only that is meaningful.
See also
Other qgs:
rfp_qgs_form_add(),
rfp_qgs_layer_rm(),
rfp_qgs_preview_set(),
rfp_qgs_raster_add(),
rfp_qgs_service_add(),
rfp_qgs_service_rm(),
rfp_qgs_services(),
rfp_qgs_style_export(),
rfp_qgs_style_set(),
rfp_qgs_subset_set(),
rfp_qgs_theme_add(),
rfp_qgs_theme_lookup(),
rfp_qgs_theme_names(),
rfp_qgs_theme_rm(),
rfp_qgs_theme_set(),
rfp_qgs_theme_unbury(),
rfp_qgs_themes(),
rfp_qgs_vector_add(),
rfp_qwc_config_create(),
rfp_raster_style_path(),
rfp_raster_styles()
Examples
qgs <- file.path(tempdir(), "subset_get.qgs")
file.copy(system.file("testdata", "raster_add_fixture.qgs", package = "rfp"),
qgs, overwrite = TRUE)
#> [1] TRUE
rfp_qgs_subset_get(qgs)
#> [1] layer id subset agrees
#> <0 rows> (or 0-length row.names)