Ensure that UUID form widget doesn't try to generate UUIDs which

are too long to fit in a string
qgis · Oct 18, 2021 · 0a35415 · 0a35415
1 parent dcf5cb6
commit 0a35415
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Showing 3 changed files with 63 additions and 2 deletions.
diff --git a/src/gui/editorwidgets/qgsuuidwidgetwrapper.cpp b/src/gui/editorwidgets/qgsuuidwidgetwrapper.cpp
@@ -23,6 +23,19 @@ QgsUuidWidgetWrapper::QgsUuidWidgetWrapper( QgsVectorLayer *layer, int fieldIdx,
 {
 }
 
+QString QgsUuidWidgetWrapper::createUiid( int maxLength )
+{
+  if ( maxLength <= 0 )
+  {
+    return QUuid::createUuid().toString();
+  }
+  else
+  {
+    // trim left "{" and remove -'s... they are wasted characters given that we have a limited length!
+    return QUuid::createUuid().toString().replace( '-', QString() ).mid( 1, maxLength );
+  }
+}
+
 QVariant QgsUuidWidgetWrapper::value() const
 {
   QVariant v;
@@ -57,10 +70,16 @@ void QgsUuidWidgetWrapper::updateValues( const QVariant &value, const QVariantLi
 {
   if ( value.isNull() )
   {
+    int maxLength = 0;
+    if ( field().type() == QVariant::String && field().length() > 0 )
+    {
+      maxLength = field().length();
+    }
+    const QString uuid = createUiid( maxLength );
     if ( mLineEdit )
-      mLineEdit->setText( QUuid::createUuid().toString() );
+      mLineEdit->setText( uuid );
     if ( mLabel )
-      mLabel->setText( QUuid::createUuid().toString() );
+      mLabel->setText( uuid );
 
     emitValueChanged();
   }

diff --git a/src/gui/editorwidgets/qgsuuidwidgetwrapper.h b/src/gui/editorwidgets/qgsuuidwidgetwrapper.h
@@ -48,7 +48,15 @@ class GUI_EXPORT QgsUuidWidgetWrapper : public QgsEditorWidgetWrapper
      */
     explicit QgsUuidWidgetWrapper( QgsVectorLayer *layer, int fieldIdx, QWidget *editor = nullptr, QWidget *parent = nullptr );
 
+    /**
+     * Creates a UUID value, respecting the specified maximum length.
+     *
+     * \since QGIS 3.22
+     */
+    static QString createUiid( int maxLength = 0 );
+
     // QgsEditorWidgetWrapper interface
+
   public:
     QVariant value() const override;
 

diff --git a/tests/src/python/test_qgseditwidgets.py b/tests/src/python/test_qgseditwidgets.py
@@ -164,5 +164,39 @@ def test_ValueMap_set_get(self):
         QgsProject.instance().removeAllMapLayers()
 
 
+class TestQgsUuidWidget(unittest.TestCase):
+
+    def test_create_uuid(self):
+        layer = QgsVectorLayer("none?field=text_no_limit:text(0)&field=text_limit:text(10)", "layer", "memory")
+        self.assertTrue(layer.isValid())
+        QgsProject.instance().addMapLayer(layer)
+
+        # unlimited length text field
+        wrapper = QgsGui.editorWidgetRegistry().create('UuidGenerator', layer, 0, {}, None, None)
+        _ = wrapper.widget()
+        feature = QgsFeature(layer.fields())
+        wrapper.setFeature(feature)
+        val = wrapper.value()
+        # we can't directly check the result, as it will be random, so just check it's general properties
+        self.assertEqual(len(val), 38)
+        self.assertEqual(val[0], '{')
+        self.assertEqual(val[-1], '}')
+
+        # limited length text field, value must be truncated
+        wrapper = QgsGui.editorWidgetRegistry().create('UuidGenerator', layer, 1, {}, None, None)
+        _ = wrapper.widget()
+        feature = QgsFeature(layer.fields())
+        wrapper.setFeature(feature)
+        val = wrapper.value()
+        # we can't directly check the result, as it will be random, so just check it's general properties
+        self.assertEqual(len(val), 10)
+        self.assertNotEqual(val[0], '{')
+        self.assertNotEqual(val[-1], '}')
+        with self.assertRaises(ValueError):
+            val.index('-')
+
+        QgsProject.instance().removeAllMapLayers()
+
+
 if __name__ == "__main__":
     unittest.main()