Extend DFTE template engine debug API and refine renderer logging.

Add helpers in DeviceFrameworkTemplateEngineDebug and wire clearer
instrumentation in DeviceFrameworkTemplateRenderer; update README.

README.md

@@ -84,7 +84,7 @@ DFTE is a lightweight C++ template engine tailored for Arduino-class hardware (E
   - `isComplete(const TemplateContext&)`, `hasError(const TemplateContext&)` – convenience checks.
 
 - `DeviceFrameworkTemplateEngineDebug`
-  - Optional logging interface; create a `DeviceFrameworkTemplateEngineLogger` subclass and call `deviceFrameworkTemplateEngineEnableLogging(&logger)`.
+  - Optional logging interface; create a `DeviceFrameworkTemplateEngineLogger` subclass and call `deviceFrameworkTemplateEngineEnableLogging(&logger)` (or the two-argument overload with an owner tag, e.g. `this`, for `deviceFrameworkTemplateEngineDisableLoggingForOwner`).
 
 All public headers are re-exported from `TemplateEngine.h`, so typical sketches only include that file.
 
@@ -313,11 +313,11 @@ SerialLogger logger;
 
 void setup() {
   Serial.begin(115200);
-  deviceFrameworkTemplateEngineEnableLogging(&logger);
+  deviceFrameworkTemplateEngineEnableLogging(&logger, static_cast<const void*>(&logger));
 }
 ```
 
-Use `deviceFrameworkTemplateEngineDisableLogging()` to silence output or `deviceFrameworkTemplateEngineIsLoggingEnabled()` to inspect the current state.
+Use `deviceFrameworkTemplateEngineDisableLogging()` to silence output, `deviceFrameworkTemplateEngineDisableLoggingForOwner(tag)` to tear down only the registration made with that owner (for example WiFiManager’s server instance), or `deviceFrameworkTemplateEngineIsLoggingEnabled()` to inspect the current state.
 
 ## License
 

include/DeviceFrameworkTemplateEngineDebug.h

@@ -41,6 +41,9 @@ public:
 // Global logger pointer - set by user or defaults to nullptr (disabled)
 extern DeviceFrameworkTemplateEngineLogger* deviceFrameworkTemplateEngineLogger;
 
+/** Opaque owner tag for the active logger (set on enable). Used to disable without clobbering another host. */
+extern const void* deviceFrameworkTemplateEngineLoggerOwner;
+
 // ============================================================================
 // LOGGING MACROS - NO-OPS BY DEFAULT
 // ============================================================================
@@ -86,6 +89,13 @@ extern DeviceFrameworkTemplateEngineLogger* deviceFrameworkTemplateEngineLogger;
     } \
 } while(0)
 
+/** Optional verbose trace (compile with -DDFTE_ENABLE_TRACE). Maps to debug() on the active logger. */
+#if defined(DFTE_ENABLE_TRACE)
+#define DFTE_LOG_TRACE(msg) DFTE_LOG_DEBUG(String(F("[TRACE] ")) + String(msg))
+#else
+#define DFTE_LOG_TRACE(msg) do { (void)0; } while(0)
+#endif
+
 // ============================================================================
 // LOGGING CONFIGURATION FUNCTIONS
 // ============================================================================
@@ -98,12 +108,21 @@ extern DeviceFrameworkTemplateEngineLogger* deviceFrameworkTemplateEngineLogger;
  */
 bool deviceFrameworkTemplateEngineEnableLogging(DeviceFrameworkTemplateEngineLogger* logger);
 
+/**
+ * Enable logging and record an owner tag (e.g. `this` of WiFiManagerServer).
+ * If ownerTag is nullptr, the logger pointer is used as the tag.
+ */
+bool deviceFrameworkTemplateEngineEnableLogging(DeviceFrameworkTemplateEngineLogger* logger, const void* ownerTag);
+
 /**
  * Disable all logging
  * Sets logger to nullptr, making all DFTE_LOG_* macros no-ops
  */
 void deviceFrameworkTemplateEngineDisableLogging();
 
+/** Disable only if the current logger was registered with this owner tag. Returns true if disabled. */
+bool deviceFrameworkTemplateEngineDisableLoggingForOwner(const void* ownerTag);
+
 /**
  * Check if logging is currently enabled
  * 
@@ -118,4 +137,6 @@ bool deviceFrameworkTemplateEngineIsLoggingEnabled();
  */
 DeviceFrameworkTemplateEngineLogger* deviceFrameworkTemplateEngineGetLogger();
 
+const void* deviceFrameworkTemplateEngineGetLoggerOwner();
+
 #endif // DEVICEFRAMEWORK_TEMPLATE_ENGINE_DEBUG_H

src/DeviceFrameworkTemplateEngineDebug.cpp

@@ -2,21 +2,39 @@
 
 // Global logger pointer - starts as nullptr (disabled by default)
 DeviceFrameworkTemplateEngineLogger* deviceFrameworkTemplateEngineLogger = nullptr;
+const void* deviceFrameworkTemplateEngineLoggerOwner = nullptr;
 
 // ============================================================================
 // LOGGING CONFIGURATION IMPLEMENTATIONS
 // ============================================================================
 
 bool deviceFrameworkTemplateEngineEnableLogging(DeviceFrameworkTemplateEngineLogger* logger) {
+    return deviceFrameworkTemplateEngineEnableLogging(logger, nullptr);
+}
+
+bool deviceFrameworkTemplateEngineEnableLogging(DeviceFrameworkTemplateEngineLogger* logger, const void* ownerTag) {
     if (logger == nullptr) {
         return false;
     }
     deviceFrameworkTemplateEngineLogger = logger;
+    deviceFrameworkTemplateEngineLoggerOwner = ownerTag ? ownerTag : static_cast<const void*>(logger);
     return true;
 }
 
 void deviceFrameworkTemplateEngineDisableLogging() {
     deviceFrameworkTemplateEngineLogger = nullptr;
+    deviceFrameworkTemplateEngineLoggerOwner = nullptr;
+}
+
+bool deviceFrameworkTemplateEngineDisableLoggingForOwner(const void* ownerTag) {
+    if (deviceFrameworkTemplateEngineLogger == nullptr || ownerTag == nullptr) {
+        return false;
+    }
+    if (deviceFrameworkTemplateEngineLoggerOwner != ownerTag) {
+        return false;
+    }
+    deviceFrameworkTemplateEngineDisableLogging();
+    return true;
 }
 
 bool deviceFrameworkTemplateEngineIsLoggingEnabled() {
@@ -25,4 +43,8 @@ bool deviceFrameworkTemplateEngineIsLoggingEnabled() {
 
 DeviceFrameworkTemplateEngineLogger* deviceFrameworkTemplateEngineGetLogger() {
     return deviceFrameworkTemplateEngineLogger;
+}
+
+const void* deviceFrameworkTemplateEngineGetLoggerOwner() {
+    return deviceFrameworkTemplateEngineLoggerOwner;
 }

src/DeviceFrameworkTemplateRenderer.cpp

@@ -261,18 +261,24 @@ static DeviceFrameworkTemplateRenderer::RenderOutcome processIteratorContext(Dev
 
 } // namespace
 
-// Helper function to convert RenderingContextType to string
-static String getContextTypeString(RenderingContextType type) {
-    switch (type) {
-        case RenderingContextType::TEMPLATE: return "TEMPLATE";
-        case RenderingContextType::PLACEHOLDER_DATA: return "PLACEHOLDER_DATA";
-        case RenderingContextType::PLACEHOLDER_TEMPLATE: return "PLACEHOLDER_TEMPLATE";
-        default: return "UNKNOWN";
-    }
-}
-
 // Helper function to log state transitions with stack state
 static void logStateTransition(DeviceFrameworkTemplateContext& ctx, const String& fromState, const String& toState, const String& reason = "") {
+#if !defined(DFTE_ENABLE_TRACE)
+    (void)ctx;
+    (void)fromState;
+    (void)toState;
+    (void)reason;
+    return;
+#else
+    auto getContextTypeString = [](RenderingContextType type) -> String {
+        switch (type) {
+            case RenderingContextType::TEMPLATE: return "TEMPLATE";
+            case RenderingContextType::PLACEHOLDER_DATA: return "PLACEHOLDER_DATA";
+            case RenderingContextType::PLACEHOLDER_TEMPLATE: return "PLACEHOLDER_TEMPLATE";
+            default: return "UNKNOWN";
+        }
+    };
+
     if (!deviceFrameworkTemplateEngineLogger) {
         return;
     }
@@ -287,6 +293,7 @@ static void logStateTransition(DeviceFrameworkTemplateContext& ctx, const String
         msg += " | Current: " + String(currentCtx->name) + " (type=" + getContextTypeString(currentCtx->type) + ")";
     }
     deviceFrameworkTemplateEngineLogger->debug(msg);
+#endif
 }
 
 static String getStateName(TemplateRenderState state) {
@@ -887,6 +894,8 @@ void DeviceFrameworkTemplateRenderer::initializeContext(DeviceFrameworkTemplateC
     
     ctx.state = TemplateRenderState::TEXT;
     logStateTransition(ctx, "INIT", "TEXT", "Initialized template context");
+    DFTE_LOG_TRACE("initializeContext len=" + String(rootCtx->context.templateCtx.templateLen) + " progmem=" +
+                   String(templateInProgmem ? 1 : 0));
 }
 
 bool DeviceFrameworkTemplateRenderer::isComplete(const DeviceFrameworkTemplateContext& ctx) {