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Read a Source Tier's Parameter Lookup

Source: R/rfp_source_lookup.R
rfp_source_lookup.Rd

The osm, url and stac tiers resolve a layer's parameters from a CSV rather than from the manifest, which carries only source_layer,source_type. This returns the validated lookup a run would use, with the shipped rows and any caller override merged the way rfp_source() merges them.

Usage

rfp_source_lookup(type, path = NULL)

Arguments

type

Character. One of "osm", "url" or "stac".

path

Character. An override CSV merged over the shipped rows, keyed on source_layer and winning where both name a layer. NULL (default) reads the shipped lookup alone.

Value

A data frame of the tier's parameters, one row per source_layer, with a lookup_source column naming the file each row came from.

Details

It exists so a caller can validate an override and report where each row came from before anything is written. Without it the only rejection of an unknown layer is inside the pass, which in rtj's refresh driver fires after a Mergin pull, a full backup and several other passes have already run.

See also

Other source: rfp_lookup_types()

Examples

# What the stac tier ships with
stac <- rfp_source_lookup("stac")
stac[, c("source_layer", "collection", "asset_layer")]
#>                 source_layer          collection                asset_layer
#> 1     floodplains.floodplain stac-floodplains-bc                 {scenario}
#> 2 floodplains.landcover_2023 stac-floodplains-bc classified_{scenario}_2023
#> 3     floodplains.transition stac-floodplains-bc                 transition