Add method to launder layer names to get them into a format

suitable for typical database layer naming

python/core/auto_generated/qgsmaplayerutils.sip.in

@@ -66,6 +66,18 @@ result list.
 .. versionadded:: 3.26
 %End
 
+    static QString launderLayerName( const QString &name );
+%Docstring
+Launders a layer's name, converting it into a format which is general suitable for
+file names or database layer names.
+
+Specifically this method:
+
+- Converts the name to lowercase
+- Replaces spaces by underscore characters
+
+.. versionadded:: 3.28
+%End
 
 };
 

src/core/qgsmaplayerutils.cpp

@@ -26,6 +26,7 @@
 #include "qgslogger.h"
 #include "qgsmaplayer.h"
 #include "qgscoordinatetransform.h"
+#include <QRegularExpression>
 
 QgsRectangle QgsMapLayerUtils::combinedExtent( const QList<QgsMapLayer *> &layers, const QgsCoordinateReferenceSystem &crs, const QgsCoordinateTransformContext &transformContext )
 {
@@ -154,3 +155,15 @@ QList<QgsMapLayer *> QgsMapLayerUtils::sortLayersByType( const QList<QgsMapLayer
   } );
   return res;
 }
+
+QString QgsMapLayerUtils::launderLayerName( const QString &name )
+{
+  QString laundered = name.toLower();
+  const thread_local QRegularExpression sRxSwapChars( QStringLiteral( "\\s" ) );
+  laundered.replace( sRxSwapChars, QStringLiteral( "_" ) );
+
+  const thread_local QRegularExpression sRxRemoveChars( QStringLiteral( "[^a-zA-Z0-9_]" ) );
+  laundered.replace( sRxRemoveChars, QString() );
+
+  return laundered;
+}

src/core/qgsmaplayerutils.h

@@ -80,6 +80,18 @@ class CORE_EXPORT QgsMapLayerUtils
      */
     static QList< QgsMapLayer * > sortLayersByType( const QList< QgsMapLayer * > &layers, const QList< QgsMapLayerType > &order );
 
+    /**
+     * Launders a layer's name, converting it into a format which is general suitable for
+     * file names or database layer names.
+     *
+     * Specifically this method:
+     *
+     * - Converts the name to lowercase
+     * - Replaces spaces by underscore characters
+     *
+     * \since QGIS 3.28
+     */
+    static QString launderLayerName( const QString &name );
 
 };
 

tests/src/python/test_qgsmaplayerutils.py

@@ -159,6 +159,9 @@ class TestQgsMapLayerUtils(unittest.TestCase):
         self.assertEqual(QgsMapLayerUtils.sortLayersByType([vl1, rl1, gp1, vl2], [QgsMapLayerType.AnnotationLayer]),
                          [vl1, rl1, gp1, vl2])
 
+    def test_launder_layer_name(self):
+        self.assertEqual(QgsMapLayerUtils.launderLayerName('abc Def4_a.h%'), 'abc_def4_ah')
+
 
 if __name__ == '__main__':
     unittest.main()