Resolve "Add processing frequency option for items"

Closes #32 (closed)

eraser-base/src/main/jastadd/Item.jrag

@@ -21,6 +21,8 @@ aspect ItemHandling {
   eq ItemWithDoubleState.getStateAsString() = Double.toString(getState());
   eq ItemWithStringState.getStateAsString() = getState();
 
+  syn LastChanged Item.getLastChanged() = new LastChanged();
+
   //--- getStateAsDouble ---
   syn double Item.getStateAsDouble();
   // TupleHSB and String work like default
@@ -285,7 +287,7 @@ aspect ItemHandling {
 
   //--- stateUpdated ---
   /**
-   * Called, whenever the state of an item is updated. Does various things including:
+   * Called, whenever the state of an item is updated. Does various things (except it has no parent) including:
    * <ul>
    *   <li>Send the new state via MQTT</li>
    *   <li>Send the new state to Influx DB</li>
@@ -294,6 +296,7 @@ aspect ItemHandling {
    * @param shouldSendState whether to send the new state (currently affects MQTT and Influx)
    */
   protected void Item.stateUpdated(boolean shouldSendState) {
+    if (getParent() == null) { return; }
     if (shouldSendState) {
       try {
         // sendState() refined in MQTT and Influx aspect
@@ -302,9 +305,13 @@ aspect ItemHandling {
         logger.catching(e);
       }
     }
-    getItemObserver().apply();
+    if (this.getLastChanged().checkStateProcessingTime(relevantFrequencySetting())) {
+      this.getLastChanged().afterStateChangeProcessed();
+      getItemObserver().apply();
+    }
   }
 
+
   //--- sendState ---
   protected void Item.sendState() throws Exception {
     for (MachineLearningModel model : getRelevantInMachineLearningModels()) {
@@ -459,6 +466,11 @@ aspect ItemHandling {
 
   }
 
+  //--- onReceiveStateChange ---
+  protected void Item.onReceiveStateChange() {
+      //Instant lastChange = this.
+  }
+
   
 
 
@@ -506,4 +518,6 @@ aspect ItemHandling {
   syn String ItemUpdate.getNewStateAsString();
   eq ItemUpdateColor.getNewStateAsString() = getNewHSB().toString();
   eq ItemUpdateDouble.getNewStateAsString() = Double.toString(getNewValue());
+
+  
 }