qgis_orderbyexpression: QGIS algorithm - Order by expression

View source: R/qgis_orderbyexpression.R

qgis_orderbyexpressionR Documentation

QGIS algorithm - Order by expression

Description

QGIS Algorithm provided by QGIS (native c++) Order by expression (native:orderbyexpression). This algorithm sorts a vector layer according to an expression. Be careful, it might not work as expected with some providers, the order might not be kept every time. For help with QGIS expression functions, see the inbuilt help for specific functions which is available in the expression builder.

Usage

qgis_orderbyexpression(
  INPUT = qgisprocess:::qgis_default_value(),
  EXPRESSION = qgisprocess:::qgis_default_value(),
  ASCENDING = qgisprocess:::qgis_default_value(),
  NULLS_FIRST = qgisprocess:::qgis_default_value(),
  OUTPUT = qgisprocess:::qgis_default_value(),
  ...,
  .complete_output = .complete_output_option(),
  .quiet = .quiet_option(),
  .messages = .message_option()
)

Arguments

INPUT

source - Input layer. Path to a vector layer.

EXPRESSION

expression - Expression. A valid QGIS expression string, e.g "road_name" = 'MAIN RD'.

ASCENDING

boolean - Sort ascending. 1 for true/yes. 0 for false/no. 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.

NULLS_FIRST

boolean - Sort nulls first. 1 for true/yes. 0 for false/no. 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.

OUTPUT

sink - Ordered. Path for new vector layer.

...

further parameters passed to qgisprocess::qgis_run_algorithm()

.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.

.quiet

logical specifying if parameter .quiet for qgisprocess::qgis_run_algorithm() Default value is TRUE.

.messages

logical specifying if messages from qgisprocess::qgis_run_algorithm() should be printed (TRUE) or not (FALSE). Default value is FALSE.

Details

Outputs description

  • OUTPUT - outputVector - Ordered


JanCaha/r_package_qgis documentation built on Nov. 3, 2024, 5:25 p.m.