R/qgis_extractbyattribute.R

In JanCaha/r_package_qgis: An extension of package "qgisprocess" providing direct R functions for QGIS functions

##' QGIS Algorithm provided by QGIS (native c++) Extract by attribute (native:extractbyattribute). This algorithm creates a new vector layer that only contains matching features from an input layer. The criteria for adding features to the resulting layer is defined based on the values of an attribute from the input layer.
##'
##' @title QGIS algorithm - Extract by attribute
##'
##' @param INPUT `source` - Input layer. Path to a vector layer.
##' @param FIELD `field` - Selection attribute. The name of an existing field. ; delimited list of existing field names.
##' @param OPERATOR `enum`  of `("=", "≠", "", "≥", "", "≤", "begins with", "contains", "is null", "is not null", "does not contain")` - Operator. Number of selected option, e.g. '1'. Comma separated list of options, e.g. '1,3'.
##' @param VALUE `string` - Value. String value. field:FIELD_NAME to use a data defined value taken from the FIELD_NAME field. expression:SOME EXPRESSION to use a data defined value calculated using a custom QGIS expression.
##' @param OUTPUT `sink` - Extracted (attribute). Path for new vector layer.
##' @param FAIL_OUTPUT `sink` - Extracted (non-matching). Path for new vector layer.
##' @param ... further parameters passed to `qgisprocess::qgis_run_algorithm()`
##' @param .complete_output logical specifying if complete out of `qgisprocess::qgis_run_algorithm()` should be used (`TRUE`) or first output (most likely the main) should read (`FALSE`). Default value is `TRUE`.
##' @param .quiet logical specifying if parameter `.quiet` for `qgisprocess::qgis_run_algorithm()` Default value is `TRUE`.
##' @param .messages logical specifying if messages from `qgisprocess::qgis_run_algorithm()` should be printed (`TRUE`) or not (`FALSE`). Default value is `FALSE`.
##'
##' @details
##' ## Outputs description
##' * FAIL_OUTPUT - outputVector - Extracted (non-matching)
##' * OUTPUT - outputVector - Extracted (attribute)
##'
##'
##' @export
##' @md
##' @importFrom qgisprocess qgis_run_algorithm

qgis_extractbyattribute <- function(INPUT = qgisprocess:::qgis_default_value(), FIELD = qgisprocess:::qgis_default_value(), OPERATOR = qgisprocess:::qgis_default_value(), VALUE = qgisprocess:::qgis_default_value(), OUTPUT = qgisprocess:::qgis_default_value(), FAIL_OUTPUT = qgisprocess:::qgis_default_value(),..., .complete_output = .complete_output_option(), .quiet = .quiet_option(), .messages = .message_option()) {

  check_algorithm_necessities("native:extractbyattribute")

  if (.messages){
    output <- qgisprocess::qgis_run_algorithm("native:extractbyattribute", `INPUT` = INPUT, `FIELD` = FIELD, `OPERATOR` = OPERATOR, `VALUE` = VALUE, `OUTPUT` = OUTPUT, `FAIL_OUTPUT` = FAIL_OUTPUT,..., .quiet = .quiet)
  } else {
    suppressMessages(
      output <- qgisprocess::qgis_run_algorithm("native:extractbyattribute", `INPUT` = INPUT, `FIELD` = FIELD, `OPERATOR` = OPERATOR, `VALUE` = VALUE, `OUTPUT` = OUTPUT, `FAIL_OUTPUT` = FAIL_OUTPUT,..., .quiet = .quiet)
      )
  }

  if (.complete_output) {
    return(output)
  }
  else{
    qgisprocess::qgis_extract_output(output, "FAIL_OUTPUT")
  }
}