[feature] Add @map_crs_projection variable for retrieving a descriptive

name of the projection used by the map (e.g. "Albers Equal Area")
qgis · May 11, 2021 · ca26f60 · ca26f60
1 parent 21edff4
commit ca26f60
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Showing 5 changed files with 13 additions and 0 deletions.
diff --git a/src/core/expression/qgsexpression.cpp b/src/core/expression/qgsexpression.cpp
@@ -786,6 +786,7 @@ void QgsExpression::initVariableHelp()
   sVariableHelpTexts()->insert( QStringLiteral( "map_units" ), QCoreApplication::translate( "variable_help", "Units for map measurements." ) );
   sVariableHelpTexts()->insert( QStringLiteral( "map_crs_definition" ), QCoreApplication::translate( "variable_help", "Coordinate reference system of the map (full definition)." ) );
   sVariableHelpTexts()->insert( QStringLiteral( "map_crs_acronym" ), QCoreApplication::translate( "variable_help", "Acronym of the coordinate reference system of the map." ) );
+  sVariableHelpTexts()->insert( QStringLiteral( "map_crs_projection" ), QCoreApplication::translate( "variable_help", "Projection method used by the coordinate reference system of the map." ) );
   sVariableHelpTexts()->insert( QStringLiteral( "map_crs_ellipsoid" ), QCoreApplication::translate( "variable_help", "Acronym of the ellipsoid of the coordinate reference system of the map." ) );
   sVariableHelpTexts()->insert( QStringLiteral( "map_crs_proj4" ), QCoreApplication::translate( "variable_help", "Proj4 definition of the coordinate reference system of the map." ) );
   sVariableHelpTexts()->insert( QStringLiteral( "map_crs_wkt" ), QCoreApplication::translate( "variable_help", "WKT definition of the coordinate reference system of the map." ) );

diff --git a/src/core/expression/qgsexpressioncontextutils.cpp b/src/core/expression/qgsexpressioncontextutils.cpp
@@ -32,6 +32,7 @@
 #include "qgsfeatureid.h"
 #include "qgslayoutitemmap.h"
 #include "qgsmaplayerlistutils.h"
+#include "qgsprojoperation.h"
 
 QgsExpressionContextScope *QgsExpressionContextUtils::globalScope()
 {
@@ -456,6 +457,7 @@ QgsExpressionContextScope *QgsExpressionContextUtils::mapSettingsScope( const Qg
   scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_units" ), QgsUnitTypes::toString( mapSettings.mapUnits() ), true ) );
   scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_crs_description" ), mapSettings.destinationCrs().description(), true ) );
   scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_crs_acronym" ), mapSettings.destinationCrs().projectionAcronym(), true ) );
+  scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_crs_projection" ), mapSettings.destinationCrs().operation().description(), true ) );
   scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_crs_ellipsoid" ), mapSettings.destinationCrs().ellipsoidAcronym(), true ) );
   scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_crs_proj4" ), mapSettings.destinationCrs().toProj(), true ) );
   scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_crs_wkt" ), mapSettings.destinationCrs().toWkt( QgsCoordinateReferenceSystem::WKT_PREFERRED ), true ) );

diff --git a/src/core/layout/qgslayoutitemmap.cpp b/src/core/layout/qgslayoutitemmap.cpp
@@ -35,6 +35,7 @@
 #include "qgsstyleentityvisitor.h"
 #include "qgsannotationlayer.h"
 #include "qgscoordinatereferencesystemregistry.h"
+#include "qgsprojoperation.h"
 
 #include <QPainter>
 #include <QStyleOptionGraphicsItem>
@@ -1676,6 +1677,7 @@ QgsExpressionContext QgsLayoutItemMap::createExpressionContext() const
   scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_crs_description" ), mapCrs.description(), true ) );
   scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_units" ), QgsUnitTypes::toString( mapCrs.mapUnits() ), true ) );
   scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_crs_acronym" ), mapCrs.projectionAcronym(), true ) );
+  scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_crs_projection" ), mapCrs.operation().description(), true ) );
   scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_crs_ellipsoid" ), mapCrs.ellipsoidAcronym(), true ) );
   scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_crs_proj4" ), mapCrs.toProj(), true ) );
   scope->addVariable( QgsExpressionContextScope::StaticVariable( QStringLiteral( "map_crs_wkt" ), mapCrs.toWkt( QgsCoordinateReferenceSystem::WKT_PREFERRED ), true ) );

diff --git a/tests/src/core/testqgslayoutmap.cpp b/tests/src/core/testqgslayoutmap.cpp
@@ -704,6 +704,10 @@ void TestQgsLayoutMap::expressionContext()
   r = e6.evaluate( &c );
   QCOMPARE( r.toString(), QString( "longlat" ) );
 
+  QgsExpression e6a( QStringLiteral( "@map_crs_projection" ) );
+  r = e6a.evaluate( &c );
+  QCOMPARE( r.toString(), QString( "Lat/long (Geodetic alias)" ) );
+
   QgsExpression e7( QStringLiteral( "@map_crs_proj4" ) );
   r = e7.evaluate( &c );
   QCOMPARE( r.toString(), QString( "+proj=longlat +datum=WGS84 +no_defs" ) );

diff --git a/tests/src/core/testqgsmapsettings.cpp b/tests/src/core/testqgsmapsettings.cpp
@@ -520,6 +520,10 @@ void TestQgsMapSettings::testExpressionContext()
   r = e.evaluate( &c );
   QCOMPARE( r.toString(), QStringLiteral( "longlat" ) );
 
+  QgsExpression e6a( QStringLiteral( "@map_crs_projection" ) );
+  r = e6a.evaluate( &c );
+  QCOMPARE( r.toString(), QString( "Lat/long (Geodetic alias)" ) );
+
   e = QgsExpression( QStringLiteral( "@map_crs_proj4" ) );
   r = e.evaluate( &c );
   QCOMPARE( r.toString(), QStringLiteral( "+proj=longlat +datum=WGS84 +no_defs" ) );