provide an alternative to Janino based conditional configuration processing - Part 3

Signed-off-by: ceki <ceki@qos.ch>

Author: ceki

logback-core-blackbox/src/test/blackboxInput/joran/conditional/ifSystem_NoJoran.xml

@@ -0,0 +1,29 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+
+<!--
+  ~ Logback: the reliable, generic, fast and flexible logging framework.
+  ~  Copyright (C) 1999-2025, QOS.ch. All rights reserved.
+  ~
+  ~ This program and the accompanying materials are dual-licensed under
+  ~ either the terms of the Eclipse Public License v1.0 as published by
+  ~ the Eclipse Foundation
+  ~
+  ~     or (per the licensee's choosing)
+  ~
+  ~ under the terms of the GNU Lesser General Public License version 2.1
+  ~ as published by the Free Software Foundation.
+  -->
+
+<x>
+    <stack name="BEGIN"/>
+
+    <condition class="ch.qos.logback.core.blackbox.boolex.IsPropertyNullCondition">
+        <key>sysKey</key>
+    </condition>
+    <if>
+        <then>
+            <property scope="context" name="dynaKey" value="dynaVal"/>
+        </then>
+    </if>
+    <stack name="END"/>
+</x>

logback-core-blackbox/src/test/java/ch/qos/logback/core/blackbox/boolex/IsPropertyNullCondition.java

@@ -0,0 +1,44 @@
+/*
+ * Logback: the reliable, generic, fast and flexible logging framework.
+ *  Copyright (C) 1999-2025, QOS.ch. All rights reserved.
+ *
+ * This program and the accompanying materials are dual-licensed under
+ * either the terms of the Eclipse Public License v1.0 as published by
+ * the Eclipse Foundation
+ *
+ *     or (per the licensee's choosing)
+ *
+ * under the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation.
+ */
+
+package ch.qos.logback.core.blackbox.boolex;
+
+import ch.qos.logback.core.boolex.PropertyEvaluatorBase;
+
+public class IsPropertyNullCondition  extends PropertyEvaluatorBase {
+
+    String key;
+
+    public void start() {
+        if (key == null) {
+            addError("In IsPropertyNullCondition 'key' parameter cannot be null");
+            return;
+        }
+        super.start();
+    }
+
+
+    public String getKey() {
+        return key;
+    }
+
+    public void setKey(String key) {
+        this.key = key;
+    }
+
+    @Override
+    public boolean evaluate() {
+        return isNull(key);
+    }
+}

logback-core-blackbox/src/test/java/ch/qos/logback/core/blackbox/joran/conditional/IfThenElseTest.java

@@ -220,9 +220,7 @@ public void nestedIf_NoJoran() throws JoranException {
         verifyConfig(new String[] { "BEGIN", "a", "c", "END" });
         Assertions.assertTrue(checker.isErrorFree(0));
     }
-
     // ----------------------------------------------------------------------------------------------------
-
     @Test
     public void useNonExistenceOfSystemPropertyToDefineAContextProperty() throws JoranException {
         Assertions.assertNull(System.getProperty(sysKey));
@@ -231,7 +229,15 @@ public void useNonExistenceOfSystemPropertyToDefineAContextProperty() throws Jor
         //System.out.println(dynaKey + "=" + context.getProperty(dynaKey));
         Assertions.assertNotNull(context.getProperty(dynaKey));
     }
-
+    @Test
+    public void useNonExistenceOfSystemPropertyToDefineAContextProperty_NoJoran() throws JoranException {
+        Assertions.assertNull(System.getProperty(sysKey));
+        Assertions.assertNull(context.getProperty(dynaKey));
+        simpleConfigurator.doConfigure(CONDITIONAL_DIR_PREFIX + "ifSystem_NoJoran.xml");
+        //System.out.println(dynaKey + "=" + context.getProperty(dynaKey));
+        Assertions.assertNotNull(context.getProperty(dynaKey));
+    }
+    // ----------------------------------------------------------------------------------------------------
     @Test
     public void noContextPropertyShouldBeDefinedIfSystemPropertyExists() throws JoranException {
         System.setProperty(sysKey, "a");
@@ -242,6 +248,17 @@ public void noContextPropertyShouldBeDefinedIfSystemPropertyExists() throws Jora
         Assertions.assertNull(context.getProperty(dynaKey));
     }
 
+    @Test
+    public void noContextPropertyShouldBeDefinedIfSystemPropertyExists_NoJoran() throws JoranException {
+        System.setProperty(sysKey, "a");
+        Assertions.assertNull(context.getProperty(dynaKey));
+        System.out.println("before " + dynaKey + "=" + context.getProperty(dynaKey));
+        simpleConfigurator.doConfigure(CONDITIONAL_DIR_PREFIX + "ifSystem_NoJoran.xml");
+        System.out.println(dynaKey + "=" + context.getProperty(dynaKey));
+        Assertions.assertNull(context.getProperty(dynaKey));
+    }
+    // ----------------------------------------------------------------------------------------------------
+
     private void verifyConfig(String[] expected) {
         Stack<String> witness = new Stack<>();
         witness.addAll(Arrays.asList(expected));

logback-core/src/main/java/ch/qos/logback/core/model/processor/conditional/ByPropertiesConditionModelHandler.java

@@ -85,6 +85,12 @@ public void postHandle(ModelInterpretationContext mic, Model model) throws Model
             mic.popObject();
         }
 
+        propertyEvaluator.start();
+        if(!propertyEvaluator.isStarted()) {
+            addError("PropertyEvaluator of type ["+propertyEvaluator.getClass().getName()+"] did not start successfully.");
+            mic.pushObject(IfModel.BranchState.IN_ERROR);
+            return;
+        }
         boolean evaluationResult = propertyEvaluator.evaluate();
         IfModel.BranchState branchState = evaluationResult ? IF_BRANCH : ELSE_BRANCH;
         mic.pushObject(branchState);