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Resolve the id column of a retrieved layer

Source: R/utils.R
layer_id_col.Rd

Returns the column that identifies each feature of layer. When the layer carries retrieval provenance, the answer comes from the source registry's declared key fields, so it matches the from_id_col / to_id_col values recorded in build_crosswalk() and build_intersection() output. Layers without provenance fall back to a name-pattern guess.

Usage

layer_id_col(layer)

Arguments

layer

An sf object or data.frame.

Value

Character scalar: the id column name.

Details

This is the supported way for a downstream caller to join a crosswalk or linked table back onto the layer geometry it came from.

See also

Other app support interfaces: build_nearest_layers(), extract_polygon_collection(), guess_name_col(), render_postal_reproducer_script(), render_reproducer_script()

Examples

layer_id_col(data.frame(PHU_ID = 2253, PHU_NAME_ENG = "Example"))
#> [1] "PHU_ID"