Build one `layer_styles` row for a GeoPackage layer

Assembles a single row in the schema QGIS expects in a GeoPackage's `layer_styles` table. The geometry column is looked up from `gpkg_geometry_columns`, so a layer without geometry (an attribute table such as `network`) yields `NULL` rather than an error: QGIS styles apply to spatial layers only.

Usage

create_style_row(gpkg_path, layer_name, style_name, style_qml)

Arguments

gpkg_path

Path to the GeoPackage.

layer_name

Layer the style applies to.

style_name

Name recorded for the style.

style_qml

QML contents, from [read_qml()].

Value

A one-row data frame, or `NULL` if `layer_name` has no geometry column in `gpkg_path`.

Examples

if (FALSE) { # \dontrun{
row <- create_style_row("hydrofabric.gpkg", "nexus", "nexus_style",
  read_qml(system.file("qml", "nexus.qml", package = "hfutils")))
} # }