Convert a FHIRPath expression to a Spark Column

Converts a FHIRPath expression into a Spark Column that can be used in DataFrame operations such as filtering and selection. Boolean expressions can be used for filtering, while other expressions can be used for value extraction.

pc_fhirpath_to_column(pc, resource_type, fhirpath_expression)

Arguments

pc

The PathlingContext object.

resource_type

A string containing the FHIR resource type code (e.g., "Patient", "Observation").

fhirpath_expression

A FHIRPath expression to evaluate (e.g., "gender = 'male'", "name.given.first()").

Value

A Spark Column object (spark_jobj) representing the evaluated expression.

Details

The expression should evaluate to a single value per resource row.

See also

Other context functions: pathling_filter(), pathling_with_column(), pc_search_to_column()

Examples

if (FALSE) { # \dontrun{
pc <- pathling_connect()
data_source <- pc %>% pathling_read_ndjson(pathling_examples("ndjson"))
patients <- data_source %>% ds_read("Patient")

# Boolean expression for filtering.
gender_filter <- pc_fhirpath_to_column(pc, "Patient", "gender = 'male'")
filtered <- sparklyr::spark_dataframe(patients) %>%
  sparklyr::j_invoke("filter", gender_filter) %>%
  sparklyr::sdf_register()

# Value expression for selection.
name_col <- pc_fhirpath_to_column(pc, "Patient", "name.given.first()")

pathling_disconnect(pc)
} # }