[expressions] Unload expression functions from project on project clo…

…se and reload user expressions (from profile) to avoid any potential overwrite from unloaded project functions

python/PyQt6/core/auto_generated/expression/qgsexpression.sip.in

@@ -520,6 +520,7 @@ Returns the number of functions defined in the parser
 %End
 
 
+
     static QString quotedColumnRef( QString name );
 %Docstring
 Returns a quoted column reference (in double quotes)

python/core/auto_generated/expression/qgsexpression.sip.in

@@ -520,6 +520,7 @@ Returns the number of functions defined in the parser
 %End
 
 
+
     static QString quotedColumnRef( QString name );
 %Docstring
 Returns a quoted column reference (in double quotes)

python/user.py

@@ -26,7 +26,7 @@
 import glob
 import traceback
 
-from qgis.PyQt.QtCore import QCoreApplication
+from qgis.PyQt.QtCore import QCoreApplication, qDebug
 from qgis.core import Qgis, QgsApplication, QgsMessageLog
 
 
@@ -51,6 +51,41 @@ def load_user_expressions(path):
             QgsMessageLog.logMessage(msg + "\n" + error, msgtitle, Qgis.MessageLevel.Warning)
 
 
+def reload_user_expressions(path):
+    """
+    Reload all user expressions from the given path
+    """
+    # First unload expression modules, looping all
+    # py files and remove them from sys.modules
+    modules = glob.glob(path + "/*.py")
+    names = [os.path.basename(f)[:-3] for f in modules]
+    for name in names:
+        if name == "__init__":
+            continue
+
+        mod = "expressions.{0}".format(name)
+        if mod not in sys.modules:
+            continue
+
+        # try removing path
+        if hasattr(sys.modules[mod], '__path__'):
+            for path in sys.modules[mod].__path__:
+                try:
+                    sys.path.remove(path)
+                except ValueError:
+                    # Discard if path is not there
+                    pass
+
+        # try to remove the module from python
+        try:
+            del sys.modules[mod]
+        except:
+            qDebug("Error when removing module:\n%s" % traceback.format_exc())
+
+    # Finally, load again the users expressions from the given path
+    load_user_expressions(path)
+
+
 userpythonhome = os.path.join(QgsApplication.qgisSettingsDirPath(), "python")
 expressionspath = os.path.join(userpythonhome, "expressions")
 
@@ -87,6 +122,7 @@ def my_sum(value1, value2):
     expressions.load = load_user_expressions
     expressions.load(expressionspath)
     expressions.template = template
+    expressions.reload = reload_user_expressions
 except ImportError:
     # We get a import error and crash for some reason even if we make the expressions package
     # TODO Fix the crash on first load with no expressions folder

python/utils.py

@@ -710,6 +710,49 @@ def closeProjectMacro():
         mod.closeProject()
 
 
+#######################
+
+def _list_project_expression_functions():
+    """ Get a list of expression functions stored in the current project """
+    import ast
+    from qgis.core import QgsProject
+
+    functions = []
+    project_functions, ok = QgsProject.instance().readEntry("ExpressionFunctions", "/pythonCode")
+    if ok and project_functions:
+        code = ast.parse(project_functions)
+
+        for e in code.body:
+            if isinstance(e, ast.FunctionDef):
+                for d in e.decorator_list:
+                    if d.func.id == "qgsfunction":
+                        functions.append(e.name)
+
+    return functions
+
+
+def clean_project_expression_functions():
+    """
+    Unload expression functions from current project
+    and reload user expressions from profile folder
+    to avoid any potential overwrite from the
+    unloaded project functions
+    """
+    project_functions = _list_project_expression_functions()
+    if project_functions:
+        from qgis.core import QgsExpression
+        for function in project_functions:
+            QgsExpression.unregisterFunction(function)
+
+        # Reload user expressions
+        from qgis.core import QgsApplication
+        import expressions
+
+        userpythonhome = os.path.join(QgsApplication.qgisSettingsDirPath(), "python")
+        expressionspath = os.path.join(userpythonhome, "expressions")
+        expressions.reload(expressionspath)
+
+
 #######################
 # SERVER PLUGINS
 #

src/app/qgisapp.cpp

@@ -13883,9 +13883,17 @@ void QgisApp::closeProject()
   {
     QgsPythonRunner::run( QStringLiteral( "qgis.utils.unloadProjectMacros();" ) );
   }
-
   mPythonMacrosEnabled = false;
 
+#ifdef WITH_BINDINGS
+  // unload the project expression functions and reload user expressions
+  const QString projectFunctions = QgsProject::instance()->readEntry( QStringLiteral( "ExpressionFunctions" ), QStringLiteral( "/pythonCode" ), QString() );
+  if ( !projectFunctions.isEmpty() )
+  {
+    QgsExpression::cleanFunctionsFromProject();
+  }
+#endif
+
   mLegendExpressionFilterButton->setExpressionText( QString() );
   mLegendExpressionFilterButton->setChecked( false );
   mFilterLegendByMapContentAction->setChecked( false );

src/core/expression/qgsexpression.h

@@ -639,6 +639,15 @@ class CORE_EXPORT QgsExpression
      */
     static bool loadFunctionsFromProject() SIP_SKIP;
 
+    /**
+     * Unloads python expression functions stored in the current project
+     * and reloads local functions from the user profile.
+     *
+     * \note not available in Python bindings
+     * \since QGIS 3.40
+     */
+    static void cleanFunctionsFromProject() SIP_SKIP;
+
     /**
      * Returns a quoted column reference (in double quotes)
      * \see quotedString()

src/core/expression/qgsexpressionfunction.cpp

@@ -9337,6 +9337,10 @@ bool QgsExpression::loadFunctionsFromProject()
   return false;
 }
 
+void QgsExpression::cleanFunctionsFromProject()
+{
+  QgsPythonRunner::run( "qgis.utils.clean_project_expression_functions()" );
+}
 
 QgsArrayForeachExpressionFunction::QgsArrayForeachExpressionFunction()
   : QgsExpressionFunction( QStringLiteral( "array_foreach" ), QgsExpressionFunction::ParameterList()  // skip-keyword-check