QGIS API Documentation 3.37.0-Master (fdefdf9c27f)
QGIS 3.0 User Changes

Table of Contents

Notes regarding user related changes for QGIS 3.0 which should be included in the release notes.

Expressions

QGIS 3.0 brings some changes to the expression engine, which may require existing projects to be updated so that any expressions in use have the following changes:

  • $rownum has been replaced by @row_number
  • $scale has been replaced by @map_scale
  • $map has been replaced by @map_id
  • $numpages has been replaced by @layout_numpages
  • $page has been replaced by @layout_page
  • $feature has been replaced by @atlas_featurenumber
  • $atlasfeatureid has been replaced by @atlas_featureid
  • $atlasfeature has been replaced by @atlas_feature
  • $atlasgeometry has been replaced by @atlas_geometry
  • $numfeatures has been replaced by @atlas_totalfeatures

Composer

Very old projects containing composer attribute tables will not restore the attribute tables when loaded into QGIS 3.0. These tables must be manually readded to the compositions.