overhauled registry

pom.xml

@@ -4,7 +4,7 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>de.srsoftware</groupId>
 	<artifactId>web4rail</artifactId>
-	<version>1.2.6</version>
+	<version>1.2.7</version>
 	<name>Web4Rail</name>
 	<packaging>jar</packaging>
 	<description>Java Model Railway Control</description>

resources/translations/Application.de.translation

@@ -146,7 +146,7 @@ Right port\: : Port für rechts
 Routes using this tile : Fahrstraßen, die diesen Abschnitt verwenden
 Route will only be available, if all conditions are fulfilled. : Route ist nur verfügbar, wenn alle Bedingungen erfüllt sind.
 Save : speichern
-Select block\: : Block auswählen:
+Select block : Block auswählen
 Select contact\: : Kotakt auswählen:
 Select display\: : Anzeige auswählen:
 Select from plan : Auf Plan auswählen

src/main/java/de/srsoftware/web4rail/Application.java

@@ -164,6 +164,11 @@ public class Application extends BaseClass{
 		return Files.probeContentType(file.toPath());
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		throw new RuntimeException(this.getClass().getSimpleName()+".removeChild should never be called!");
+	}
+	
 	/**
 	 * sends a response generated from the application to a given client
 	 * @param client

src/main/java/de/srsoftware/web4rail/BaseClass.java

@@ -39,6 +39,7 @@ public abstract class BaseClass implements Constants{
 	private static final char[] HEX_CHARS = "0123456789ABCDEF".toCharArray();
 	protected Id id = null;
 	protected String notes;
+	private static HashMap<Id,BaseClass> registry = new HashMap<BaseClass.Id, BaseClass>();
 	
 	public static final Logger LOG = LoggerFactory.getLogger(BaseClass.class);
 	private BaseClass parent;
@@ -259,6 +260,17 @@ public abstract class BaseClass implements Constants{
 		return form;
 	}
 	
+	@SuppressWarnings("unchecked")
+	public static <T> T get(Id id) {
+		BaseClass element = registry.get(id);
+		if (isNull(element)) return null;
+		try {
+			return (T) element;
+		} catch (ClassCastException e) {
+			return null;
+		}		
+	}
+	
 	public Id id() {
 		if (isNull(id)) id = new Id();
 		return id;
@@ -288,6 +300,25 @@ public abstract class BaseClass implements Constants{
 		return new Tag(tagClass).clazz("link").attr("onclick","request("+json+")").content(caption.toString());
 	}
 	
+	@SuppressWarnings("unchecked")
+	public static <T extends BaseClass> List<T> listElements(Class<T> cls) {
+		ArrayList<T> result = new ArrayList<T>();
+		for (BaseClass object : registry.values()) {
+			if (isSet(object) && cls.isAssignableFrom(object.getClass())) {
+				result.add((T) object);
+			}
+		}
+		return result;
+	}
+	
+	public BaseClass load(JSONObject json) {
+		if (json.has(ID)) {
+			id = Id.from(json);
+			register();
+		}
+		if (json.has(NOTES)) notes = json.getString(NOTES);
+		return this;
+	}
 	
 	public static String md5sum(Object o) {
 		try {
@@ -350,6 +381,18 @@ public abstract class BaseClass implements Constants{
 		return props;
 	}
 	
+	public BaseClass register() {
+		registry.put(id(),this);
+		return this;
+	}
+	
+	public BaseClass remove() {
+		if (isSet(parent)) parent.removeChild(this);
+		return registry.remove(id());
+	}
+		
+	protected abstract void removeChild(BaseClass child);
+
 	protected static String t(String txt, Object...fills) {
 		return Translation.get(Application.class, txt, fills);
 	}
@@ -359,10 +402,4 @@ public abstract class BaseClass implements Constants{
 		if (params.containsKey(NOTES)) notes = params.get(NOTES).trim();
 		return this;
 	}
-
-	public BaseClass load(JSONObject json) {
-		if (json.has(ID)) id = Id.from(json);
-		if (json.has(NOTES)) notes = json.getString(NOTES);
-		return this;
-	}
 }

src/main/java/de/srsoftware/web4rail/Constants.java

@@ -58,6 +58,7 @@ public interface Constants {
 	public static final String  ID                  = "id";
 	public static final String  NBSP                = " ";
 	public static final String  NOTES               = "notes";
+	public static final String  PARENT              = "parent";
 	public static final String  PORT                = "port";
 	public static final String  RELAY               = "relay";
 	public static final String  TYPE                = "type";

src/main/java/de/srsoftware/web4rail/PathFinder.java

@@ -109,4 +109,9 @@ public class PathFinder extends BaseClass{
 		
 		return selectetRoute;
 	}
+	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
 }

src/main/java/de/srsoftware/web4rail/Plan.java

@@ -12,13 +12,10 @@ import java.util.Collection;
 import java.util.Comparator;
 import java.util.Date;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
-import java.util.SortedSet;
 import java.util.Stack;
-import java.util.TreeSet;
 import java.util.Vector;
 
 import org.json.JSONArray;
@@ -27,7 +24,6 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import de.srsoftware.tools.Tag;
-import de.srsoftware.web4rail.actions.Action;
 import de.srsoftware.web4rail.moving.Car;
 import de.srsoftware.web4rail.moving.Train;
 import de.srsoftware.web4rail.tags.Button;
@@ -61,7 +57,6 @@ import de.srsoftware.web4rail.tiles.EndW;
 import de.srsoftware.web4rail.tiles.Eraser;
 import de.srsoftware.web4rail.tiles.Relay;
 import de.srsoftware.web4rail.tiles.Shadow;
-import de.srsoftware.web4rail.tiles.Signal;
 import de.srsoftware.web4rail.tiles.SignalE;
 import de.srsoftware.web4rail.tiles.SignalN;
 import de.srsoftware.web4rail.tiles.SignalS;
@@ -140,10 +135,6 @@ public class Plan extends BaseClass{
 	private static final String SPEED_UNIT = "speed_unit";
 	private static final String LENGTH_UNIT = "length_unit";
 	
-	public HashMap<Id,Tile> tiles = new HashMap<Id,Tile>(); // The list of tiles of this plan, i.e. the Track layout
-	private HashSet<Block> blocks = new HashSet<Block>(); // the list of tiles, that are blocks
-	private HashSet<Signal> signals = new HashSet<Signal>(); // the list of tiles, that are signals
-	private HashMap<Id, Route> routes = new HashMap<Id, Route>(); // the list of routes of the track layout
 	private ControlUnit controlUnit = new ControlUnit(this); // the control unit, to which the plan is connected 
 	private Contact learningContact;
 	
@@ -241,8 +232,11 @@ public class Plan extends BaseClass{
 		Tile tile = (Tile) tc.getClassLoader().loadClass(clazz).getDeclaredConstructor().newInstance();
 		if (tile instanceof Eraser) {
 			Tile erased = get(Tile.id(x,y),true);
-			remove(erased);
-			return erased == null ? null : t("Removed {}.",erased);
+			if (isSet(erased)) {
+				erased.remove();
+				return t("Removed {}.",erased);
+			}
+			return null;
 		}
 		//if (configJson != null) tile.configure(new JSONObject(configJson));		
 		set(x, y, tile);
@@ -255,7 +249,7 @@ public class Plan extends BaseClass{
 	 */
 	private String analyze() {
 		Vector<Route> routes = new Vector<Route>();
-		for (Block block : blocks) {
+		for (Block block : BaseClass.listElements(Block.class)) {
 			if (block.name.equals("Huhu")) {
 				System.err.println("Here we go!");
 			}
@@ -263,18 +257,11 @@ public class Plan extends BaseClass{
 				routes.addAll(follow(new Route().begin(block,con.from.inverse()),con));
 			}
 		}
-		for (Tile tile : tiles.values()) tile.routes().clear();
+		for (Tile tile : BaseClass.listElements(Tile.class)) tile.routes().clear();
 		for (Route route : routes) registerRoute(route.complete());
 		return t("Found {} routes.",routes.size());
 	}
 
-	/**
-	 * @return the list of blocks known to the plan, ordered by name
-	 */
-	public Collection<Block> blocks() {
-		return new TreeSet<Block>(blocks);
-	}
-	
 	/**
 	 * calls tile.click()
 	 * @param tile
@@ -342,7 +329,7 @@ public class Plan extends BaseClass{
 	 */
 	public Tile get(Id tileId,boolean resolveShadows) {
 		if (isNull(tileId)) return null;
-		Tile tile = tiles.get(tileId);
+		Tile tile = BaseClass.get(tileId);
 		if (resolveShadows && tile instanceof Shadow) tile = ((Shadow)tile).overlay();
 		return tile;
 	}
@@ -391,7 +378,7 @@ public class Plan extends BaseClass{
 	 */
 	public Page html() throws IOException {
 		Page page = new Page().append("<div id=\"plan\"><div id=\"scroll\">");
-		for (Tile tile: tiles.values()) {
+		for (Tile tile: BaseClass.listElements(Tile.class)) {
 			if (tile == null) continue;
 			page.append("\t\t"+tile.tag(null)+"\n");
 		}
@@ -570,7 +557,7 @@ public class Plan extends BaseClass{
 			tile = stack.pop();
 			if (!(tile instanceof Shadow)) {
 				LOG.debug("altering position of {}",tile);
-				remove(tile);
+				tile.remove();
 				set(tile.x+xstep,tile.y+ystep,tile);
 			}
 		}
@@ -628,7 +615,7 @@ public class Plan extends BaseClass{
 		new Tag("h4").content(t("turnout properties")).addTo(win);
 		Table table = new Table();
 		table.addHead(t("Address"),t("Relay/Turnout"));
-		tiles.values()
+		BaseClass.listElements(Tile.class)
 			.stream()
 			.filter(tile -> tile instanceof Device )
 			.map(tile -> (Device) tile)
@@ -658,38 +645,19 @@ public class Plan extends BaseClass{
 	 */
 	Route registerRoute(Route newRoute) {
 		newRoute.path().stream().filter(Tile::isSet).forEach(tile -> tile.add(newRoute));
-		Id newRouteId = newRoute.id();
-		Route existingRoute = routes.get(newRouteId);
+		Route existingRoute = BaseClass.get(newRoute.id());
 		if (isSet(existingRoute)) newRoute.addPropertiesFrom(existingRoute);
-		routes.put(newRouteId, newRoute);
+		newRoute.register();
 		return newRoute;
 	}
 	
-	/**
-	 * removes a tile from the track layout
-	 * @param tile
-	 */
-	private void remove(Tile tile) {
-		if (isNull(tile)) return;
-		removeTile(tile.x,tile.y);
-		if (tile instanceof Block) blocks.remove(tile);
+	@Override
+	protected void removeChild(BaseClass child) {
+		if (child instanceof Tile) {
+			Tile tile = (Tile) child;
 			for (int i=1; i<tile.width(); i++) removeTile(tile.x+i, tile.y); // remove shadow tiles
 			for (int i=1; i<tile.height(); i++) removeTile(tile.x, tile.y+i); // remove shadow tiles
-		if (tile != null) stream("remove "+tile.id());
-	}
-	
-	/**
-	 * removes a route from the track layout
-	 * @param route
-	 * @return 
-	 */
-	public String remove(Route route) {
-		for (Tile tile : route.path()) tile.remove(route);
-		for (Train train : Train.list()) {
-			if (train.route == route) train.route = null;
 		}
-		routes.remove(route.id());
-		return t("Removed {}.",route);
 	}
 
 	/**
@@ -698,16 +666,8 @@ public class Plan extends BaseClass{
 	 * @param y
 	 */
 	private void removeTile(int x, int y) {
-		LOG.debug("removed {} from tile list",tiles.remove(Tile.id(x, y)));
-	}
-	
-	/**
-	 * returns a specific route from the list of routes assigned to this plan
-	 * @param routeId the id of the route requestd
-	 * @return
-	 */
-	public Route route(Id routeId) {
-		return routes.get(routeId);
+		Tile tile = BaseClass.get(Tile.id(x, y));
+		if (isSet(tile)) tile.remove();
 	}
 	
 	/**
@@ -719,9 +679,10 @@ public class Plan extends BaseClass{
 	private String saveTo(String name) throws IOException {
 		if (name == null || name.isEmpty()) throw new NullPointerException("Name must not be empty!");
 		Car.saveAll(name+".cars");		
-		Tile.saveAll(tiles,name+".plan");
+		
+		Tile.saveAll(name+".plan");
 		Train.saveAll(name+".trains"); // refers to cars, blocks		
-		Route.saveAll(routes.values(),name+".routes"); // refers to tiles
+		Route.saveAll(name+".routes"); // refers to tiles
 		controlUnit.save(name+".cu");
 		
 		BufferedWriter file = new BufferedWriter(new FileWriter(name+".plan"));
@@ -733,8 +694,8 @@ public class Plan extends BaseClass{
 	
 	public JSONObject json() {
 		JSONArray jTiles = new JSONArray();
-		tiles.values().stream()
-			.filter(tile -> isSet(tile))
+		BaseClass.listElements(Tile.class)
+			.stream()
 			.filter(tile -> !(tile instanceof Shadow))
 			.map(tile -> tile.json())
 			.forEach(jTiles::put);
@@ -754,8 +715,6 @@ public class Plan extends BaseClass{
 	 */
 	public void set(int x,int y,Tile tile) throws IOException {
 		if (tile == null) return;
-		if (tile instanceof Block) blocks.add((Block) tile);
-		if (tile instanceof Signal) signals .add((Signal) tile);
 		for (int i=1; i<tile.width(); i++) set(x+i,y,new Shadow(tile));
 		for (int i=1; i<tile.height(); i++) set(x,y+i,new Shadow(tile));
 		setIntern(x,y,tile);
@@ -769,8 +728,7 @@ public class Plan extends BaseClass{
 	 * @param tile
 	 */
 	private void setIntern(int x, int y, Tile tile) {
-		tile.position(x, y);
-		tiles.put(tile.id(),tile);
+		tile.position(x, y).register();
 	}
 	
 	public void sensor(int addr, boolean active) {
@@ -789,34 +747,6 @@ public class Plan extends BaseClass{
 		if (isSet(contact)) contact.activate(active);
 	}
 	
-	/**
-	 * shows the properties of an entity specified in the params.context value
-	 * @param params
-	 * @return
-	 */
-	public Tag showContext(HashMap<String, String> params) {
-		String[] parts = params.get(CONTEXT).split(":");
-		String realm = parts[0];
-		Id id = parts.length>1 ? new Id(parts[1]) : null;
-		switch (realm) {
-			case REALM_ROUTE:
-				return route(id).properties();
-			case REALM_CONTACT:
-			case REALM_PLAN:
-				Tile tile = get(id, false);
-				return isNull(tile) ? null : tile.properties();
-			case REALM_ACTIONS:
-				Action action = Action.get(id);
-				return (isSet(action)) ? action.properties() : null;
-				
-		}
-		return null;
-	}
-	
-	public SortedSet<Signal> signals() {
-		return new TreeSet<Signal>(signals);
-	}
-	
 	/**
 	 * sends some data to the clients
 	 * @param data

src/main/java/de/srsoftware/web4rail/Range.java

@@ -29,6 +29,11 @@ public class Range extends BaseClass{
 		return min + random.nextInt(max - min);
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
+
 	@Override
 	public String toString() {
 		return min+"…"+max;

src/main/java/de/srsoftware/web4rail/Route.java

@@ -4,7 +4,6 @@ import java.io.BufferedWriter;
 import java.io.FileInputStream;
 import java.io.FileWriter;
 import java.io.IOException;
-import java.util.Collection;
 import java.util.Date;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -57,7 +56,6 @@ public class Route extends BaseClass implements Comparable<Route>{
 	private static final String ACTION_LISTS = "action_lists";
 	private static final String BRAKE_TIMES = "brake_times";
 	private static final String CONDITIONS = "conditions";
-	private static final String DROP_CONDITION = "drop_condition";
   	private static final String END_DIRECTION   = "direction_end";
 	private static final String ROUTES = "routes";
 	private static final String SETUP_ACTIONS = "setup_actions";
@@ -141,7 +139,6 @@ public class Route extends BaseClass implements Comparable<Route>{
 	private boolean                        disabled = false;
 	private Block                          endBlock = null;
 	public  Direction					   endDirection;
-	private Id                             id;
 	private Vector<Tile>                   path;
 	private Vector<Signal>                 signals;
 	public  Train                          train;
@@ -165,23 +162,17 @@ public class Route extends BaseClass implements Comparable<Route>{
 	 * @throws IOException 
 	 */
 	public static Object action(HashMap<String, String> params) throws IOException {
-		Route route = plan.route(Id.from(params));
+		Route route = BaseClass.get(Id.from(params));
 		if (isNull(route)) return t("Unknown route: {}",params.get(ID));
 		switch (params.get(ACTION)) {
 			case ACTION_DROP:
-				String message = plan.remove(route);
-				String context = params.get(CONTEXT);
-				if (isSet(context)) {
-					plan.stream(message);
-					return plan.showContext(params);
-				}
-				return message;
+				route.remove();
+				return t("Removed {}.",route);
+				
 			case ACTION_PROPS:
 				return route.properties();
 			case ACTION_UPDATE:
 				return route.update(params,plan);
-			case DROP_CONDITION:
-				return route.dropCodition(params);
 		}
 		return t("Unknown action: {}",params.get(ACTION));
 	}
@@ -419,12 +410,6 @@ public class Route extends BaseClass implements Comparable<Route>{
 		return disabled;
 	}
 	
-	private Object dropCodition(HashMap<String, String> params) {
-		Id condId = Id.from(params,REALM_CONDITION);
-		if (isSet(condId)) conditions.removeById(condId);
-		return properties();
-	}
-		
 	public Block endBlock() {
 		return endBlock;
 	}	
@@ -435,7 +420,7 @@ public class Route extends BaseClass implements Comparable<Route>{
 		Tile lastTile = path.lastElement();
 		if (lastTile instanceof Contact) {
 			lastTile.set(null);
-			if (isSet(train)) train.removeFromTrace(lastTile);
+			if (isSet(train)) train.removeChild(lastTile);
 		}
 		if (isSet(train)) { 
 			train.set(endBlock);
@@ -508,7 +493,7 @@ public class Route extends BaseClass implements Comparable<Route>{
 		
 		json.put(BRAKE_TIMES, brakeTimes);
 		
-		if (!conditions.isEmpty()) json.put(CONDITIONS, conditions.json());
+		if (!conditions.isEmpty()) json.put(CONDITIONS, conditions.jsonArray());
 		
 		JSONArray jTriggers = new JSONArray();
 		for (Entry<String, ActionList> entry : triggers.entrySet()) {
@@ -652,20 +637,32 @@ public class Route extends BaseClass implements Comparable<Route>{
 	@Override
 	protected Window properties(List<Fieldset> preForm, FormInput formInputs, List<Fieldset> postForm) {
 
+		preForm.add(conditions.list(t("Route will only be available, if all conditions are fulfilled.")));
+		preForm.add(contactsAndActions());
+
 		formInputs.add(t("Name"),new Input(NAME, name()));
 		formInputs.add(t("State"),new Checkbox(DISABLED, t("disabled"), disabled));
 		
 		postForm.add(basicProperties());
 		if (!turnouts.isEmpty()) postForm.add(turnouts());
-		preForm.add(conditions.list(t("Route will only be available, if all conditions are fulfilled.")));
-		preForm.add(contactsAndActions());
 		postForm.add(brakeTimes());
 		return super.properties(preForm, formInputs, postForm);
 	}
 
-	public Route remove(Condition condition) {
-		conditions.remove(condition);	
-		return this;
+	@Override
+	protected void removeChild(BaseClass child) {
+		conditions.remove(child);
+		contacts.remove(child);
+		if (child == endBlock) endBlock = null;
+		path.remove(child);
+		signals.remove(child);
+		if (child == train) train = null;
+		for (ActionList list : triggers.values()) list.removeChild(child);
+		turnouts.remove(child);
+		setupActions.removeChild(child);
+		startActions.removeChild(child);
+		if (child == startBlock) startBlock = null;
+		triggeredContacts.remove(child);
 	}
 	
 	public boolean reset() {
@@ -674,7 +671,7 @@ public class Route extends BaseClass implements Comparable<Route>{
 		Tile lastTile = path.lastElement();
 		if (lastTile instanceof Contact) {
 			lastTile.set(null);
-			if (isSet(train)) train.removeFromTrace(lastTile);
+			if (isSet(train)) train.removeChild(lastTile);
 		}
 		if (isSet(train)) {
 			train.set(startBlock);
@@ -686,10 +683,11 @@ public class Route extends BaseClass implements Comparable<Route>{
 		return true;
 	}
 
-	public static void saveAll(Collection<Route> routes, String filename) throws IOException {
+	public static void saveAll(String filename) throws IOException {
 		BufferedWriter file = new BufferedWriter(new FileWriter(filename));
 		file.write("{\""+ROUTES+"\":[\n");
 		int count = 0;
+		List<Route> routes = BaseClass.listElements(Route.class);
 		for (Route route : routes) {			
 			file.write(route.json().toString());
 			if (++count < routes.size()) file.write(",");
@@ -777,13 +775,7 @@ public class Route extends BaseClass implements Comparable<Route>{
 		if (isSet(condition)) {
 			condition.parent(this);
 			conditions.add(condition);
-			return properties();
-		}
-		String message = t("{} updated.",this); 
-		if (params.containsKey(CONTEXT)) {
-			plan.stream(message);
-			return plan.showContext(params);
 		}
-		return message;
+		return properties();
 	}
 }

src/main/java/de/srsoftware/web4rail/actions/Action.java

@@ -13,6 +13,7 @@ import de.keawe.tools.translations.Translation;
 import de.srsoftware.tools.Tag;
 import de.srsoftware.web4rail.Application;
 import de.srsoftware.web4rail.BaseClass;
+import de.srsoftware.web4rail.Window;
 import de.srsoftware.web4rail.tags.Label;
 import de.srsoftware.web4rail.tags.Select;
 
@@ -103,6 +104,10 @@ public abstract class Action extends BaseClass {
 		return false;
 	}
 
+	@Override
+	public Window properties() { // goes up to first ancestor, which is not an Action
+		return parent().properties();
+	}
 	
 	public static Tag selector() {
 		Select select = new Select(TYPE);
@@ -129,13 +134,6 @@ public abstract class Action extends BaseClass {
 	@Override
 	protected Object update(HashMap<String, String> params) {
 		super.update(params);
-		BaseClass parent = parent();
-		if (isNull(parent)) return properties();
-		if (parent instanceof ActionList) {
-			ActionList al = (ActionList) parent;
-			return al.parent().properties();
-		}
-		return parent.properties();
-		
+		return properties();		
 	}
 }

src/main/java/de/srsoftware/web4rail/actions/ActionList.java

@@ -1,6 +1,7 @@
 package de.srsoftware.web4rail.actions;
 
 import java.util.HashMap;
+import java.util.Iterator;
 import java.util.List;
 import java.util.Vector;
 
@@ -18,10 +19,10 @@ import de.srsoftware.web4rail.tags.Fieldset;
 import de.srsoftware.web4rail.tags.Form;
 import de.srsoftware.web4rail.tags.Input;
 
-public class ActionList extends Action{
-	private static final Logger LOG = LoggerFactory.getLogger(ActionList.class);
+public class ActionList extends Action implements Iterable<Action>{
+	static final Logger LOG = LoggerFactory.getLogger(ActionList.class);
 	
-	private Vector<Action> actions;
+	protected Vector<Action> actions;
 	
 	public ActionList(BaseClass parent) {
 		super(parent);
@@ -51,7 +52,7 @@ public class ActionList extends Action{
 		Action action = Action.create(type,this);
 		if (action instanceof Action) {
 			add(action);
-			return plan.showContext(params);
+			return parent().properties();
 		} 
 		actionTypeForm(win,context);
 		new Tag("span").content(t("Unknown action type: {}",type)).addTo(win);
@@ -81,10 +82,6 @@ public class ActionList extends Action{
 		}
 	}
 	
-	public boolean isEmpty() {
-		return actions.isEmpty();
-	}
-	
 	public boolean drop(Action action) {
 		return actions.remove(action);
 	}
@@ -97,6 +94,22 @@ public class ActionList extends Action{
 		return true;
 	}
 	
+	@Override
+	public Iterator<Action> iterator() {
+		return actions.iterator();
+	}
+			
+	public boolean isEmpty() {
+		return actions.isEmpty();
+	}
+
+	
+	@Override
+	public JSONObject json() {
+		String cls = getClass().getSimpleName();
+		throw new UnsupportedOperationException(cls+".json() not supported, use "+cls+".jsonArray instead!");
+	}
+	
 	public JSONArray jsonArray() {
 		JSONArray result = new JSONArray();
 		for (Action action : actions) result.put(action.json());
@@ -104,7 +117,7 @@ public class ActionList extends Action{
 	}
 
 	public Tag list() {
-		Button button = button(t("Add action"), contextAction(ACTION_ADD_ACTION));
+		Button button = button(t("add action"), contextAction(ACTION_ADD_ACTION));
 		Tag span = new Tag("span");
 		button.addTo(span);
 		
@@ -116,6 +129,7 @@ public class ActionList extends Action{
 				if (first) {
 					first = false;
 				} else action.button("↑", contextAction(ACTION_MOVE)).addTo(item.content(NBSP));
+				if (action instanceof ActionList) ((ActionList) action).list().addTo(item);
 				item.addTo(list);
 			}
 			list.addTo(span);
@@ -160,9 +174,9 @@ public class ActionList extends Action{
 				if (isNull(actionList)) return t("Id ({}) does not belong to ActionList!",actionId);
 				return actionList.addActionForm(params,plan);
 			case ACTION_DROP:
-				return action.drop() ? action.parent().properties() : t("No action with id {} found!",actionId);
+				return action.drop() ? action.properties() : t("No action with id {} found!",actionId);
 			case ACTION_MOVE:
-				return action.moveUp() ? action.parent().properties() : t("No action with id {} found!",actionId);
+				return action.moveUp() ? action.properties() : t("No action with id {} found!",actionId);
 			case ACTION_PROPS:
 				return action.properties();
 			case ACTION_UPDATE:
@@ -178,4 +192,9 @@ public class ActionList extends Action{
 		preForm.add(fieldset);
 		return super.properties(preForm, formInputs, postForm);
 	}
+	
+	@Override
+	public void removeChild(BaseClass child) {
+		actions.remove(child);
+	}
 }

src/main/java/de/srsoftware/web4rail/actions/BrakeCancel.java

@@ -15,4 +15,8 @@ public class BrakeCancel extends Action {
 		return true;
 	}
 
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
 }

src/main/java/de/srsoftware/web4rail/actions/BrakeStart.java

@@ -16,4 +16,8 @@ public class BrakeStart extends Action {
 		return true;
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
 }

src/main/java/de/srsoftware/web4rail/actions/BrakeStop.java

@@ -15,4 +15,8 @@ public class BrakeStop extends Action {
 		return true;
 	}
 
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
 }

src/main/java/de/srsoftware/web4rail/actions/ConditionalAction.java

@@ -17,20 +17,14 @@ import de.srsoftware.web4rail.tags.Fieldset;
 import de.srsoftware.web4rail.tags.Form;
 import de.srsoftware.web4rail.tags.Input;
 
-public class ConditionalAction extends Action {
+public class ConditionalAction extends ActionList {
 	
 	private static final String CONDITIONS = "conditions";
 	private static final String ACTIONS = "actions";
 	private Vector<Condition> conditions = new Vector<Condition>();
-	private ActionList actions;
 
 	public ConditionalAction(BaseClass parent) {
 		super(parent);
-		actions = new ActionList(this);
-	}
-
-	public ActionList children() {
-		return actions;
 	}
 
 	private StringBuffer conditions() {
@@ -77,7 +71,7 @@ public class ConditionalAction extends Action {
 		for (Condition condition : conditions) {
 			if (!condition.fulfilledBy(context)) return true;
 		}
-		return actions.fire(context.clone()); // actions, that happen within the conditional action list must not modify the global context.
+		return super.fire(context.clone()); // actions, that happen within the conditional action list must not modify the global context.
 	}
 	
 	@Override
@@ -86,7 +80,7 @@ public class ConditionalAction extends Action {
 		JSONArray conditions = new JSONArray();
 		for (Condition condition : this.conditions) conditions.put(condition.json());
 		json.put(CONDITIONS, conditions);
-		json.put(ACTIONS, actions.jsonArray());
+		json.put(ACTIONS, super.jsonArray());
 		return json;
 	}
 	
@@ -103,7 +97,7 @@ public class ConditionalAction extends Action {
 				}
 			}
 		}
-		actions.load(json.getJSONArray(ACTIONS));
+		super.load(json.getJSONArray(ACTIONS));
 		return this;
 	}
 
@@ -111,15 +105,15 @@ public class ConditionalAction extends Action {
 	protected Window properties(List<Fieldset> preForm, FormInput formInputs, List<Fieldset> postForm) {
 		preForm.add(conditionForm());
 		Fieldset fieldset = new Fieldset(t("Actions"));
-		actions.list().addTo(fieldset);
+		list().addTo(fieldset);
 		postForm.add(fieldset);
 		return super.properties(preForm, formInputs, postForm);
 		
 	}
 
-	public ConditionalAction remove(Condition condition) {
-		conditions.remove(condition);
-		return this;
+	@Override
+	public void removeChild(BaseClass child) {
+		conditions.remove(child);
 	}
 
 	@Override

src/main/java/de/srsoftware/web4rail/actions/DelayedAction.java

@@ -11,22 +11,16 @@ import de.srsoftware.web4rail.Window;
 import de.srsoftware.web4rail.tags.Fieldset;
 import de.srsoftware.web4rail.tags.Input;
 
-public class DelayedAction extends Action {
+public class DelayedAction extends ActionList {
 	
 
 	private static final String ACTIONS = "actions";
 	public static final String DELAY = "delay";
 	private static final int DEFAULT_DELAY = 1000;
 	private int delay = DEFAULT_DELAY;
-	private ActionList actions;
 		
 	public DelayedAction(BaseClass parent) {
 		super(parent);
-		actions = new ActionList(this);
-	}
-
-	public ActionList children() {
-		return actions;
 	}
 		
 	public boolean equals(DelayedAction other) {
@@ -43,7 +37,7 @@ public class DelayedAction extends Action {
 				} catch (InterruptedException e) {
 					LOG.warn("Interrupted Exception thrown while waiting:",e);
 				}
-				actions.fire(context);
+				DelayedAction.super.fire(context);
 			};
 		}.start();
 		return true;		
@@ -53,14 +47,14 @@ public class DelayedAction extends Action {
 	public JSONObject json() {
 		JSONObject json = super.json();
 		json.put(DELAY, delay);
-		json.put(ACTIONS, actions.jsonArray());
+		json.put(ACTIONS, jsonArray());
 		return json;
 	}
 	
 	public DelayedAction load(JSONObject json) {
 		super.load(json);
 		delay = json.getInt(DELAY);
-		if (json.has(ACTIONS)) actions.load(json.getJSONArray(ACTIONS));
+		if (json.has(ACTIONS)) super.load(json.getJSONArray(ACTIONS));
 		return this;
 	}
 		
@@ -68,7 +62,7 @@ public class DelayedAction extends Action {
 	protected Window properties(List<Fieldset> preForm, FormInput formInputs, List<Fieldset> postForm) {
 		formInputs.add(t("Delay"),new Input(DELAY,delay).numeric().addTo(new Tag("span")).content(NBSP+"ms"));
 		Fieldset fieldset = new Fieldset(t("Actions"));
-		actions.list().addTo(fieldset);
+		list().addTo(fieldset);
 		postForm.add(fieldset);
 		return super.properties(preForm, formInputs, postForm);
 	}

src/main/java/de/srsoftware/web4rail/actions/DetermineTrainInBlock.java

@@ -46,6 +46,11 @@ public class DetermineTrainInBlock extends Action {
 		return super.properties(preForm, formInputs, postForm);
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		if (child == block) block = null;
+	}
+	
 	public String toString() {
 		return isSet(block) ? t("Determine, which train is in {}",block) : t("[Click here to select block!]");
 	};

src/main/java/de/srsoftware/web4rail/actions/FinishRoute.java

@@ -15,4 +15,9 @@ public class FinishRoute extends Action {
 		if (isSet(route)) route.finish();
 		return true;
 	}
+	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
 }

src/main/java/de/srsoftware/web4rail/actions/PreserveRoute.java

@@ -30,4 +30,8 @@ public class PreserveRoute extends Action {
 		return true;
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
 }

src/main/java/de/srsoftware/web4rail/actions/SendCommand.java

@@ -54,6 +54,11 @@ public class SendCommand extends Action{
 		return super.properties(preForm, formInputs, postForm);
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
+		
 	@Override
 	public String toString() {
 		return t("Send command \"{}\" to control unit",command);

src/main/java/de/srsoftware/web4rail/actions/SetContextTrain.java

@@ -12,12 +12,12 @@ import de.srsoftware.web4rail.tags.Fieldset;
 
 public class SetContextTrain extends Action {
 		
+	private Train train = null;
+
 	public SetContextTrain(BaseClass parent) {
 		super(parent);
 	}
 	
-	private Train train = null;
-	
 	@Override
 	public boolean fire(Context context) {
 		context.train(train);		
@@ -55,6 +55,11 @@ public class SetContextTrain extends Action {
 		return super.properties(preForm, formInputs, postForm);
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		if (child == train) train = null;		
+	}
+	
 	public String toString() {
 		return isSet(train) ? t("Set {} as context",train) : "["+t("Click here to select train!")+"]";
 	};

src/main/java/de/srsoftware/web4rail/actions/SetDisplayText.java

@@ -13,13 +13,13 @@ import de.srsoftware.web4rail.tiles.TextDisplay;
 
 public class SetDisplayText extends TextAction{
 
+	private TextDisplay display;
+	private static final String DISPLAY = "display";
+
 	public SetDisplayText(BaseClass parent) {
 		super(parent);
 	}
 	
-	private TextDisplay display;
-	private static final String DISPLAY = "display";
-	
 	@Override
 	public boolean fire(Context context) {
 		plan.place(display.text(fill(text, context)));
@@ -51,6 +51,11 @@ public class SetDisplayText extends TextAction{
 		return super.load(json);
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		if (child == display) display = null;
+	}
+	
 	@Override
 	protected Window properties(List<Fieldset> preForm, FormInput formInputs, List<Fieldset> postForm) {
 		formInputs.add(t("Select display"),TextDisplay.selector(display, null));

src/main/java/de/srsoftware/web4rail/actions/SetPower.java

@@ -68,6 +68,11 @@ public class SetPower extends Action{
 		return super.properties(preForm, formInputs, postForm);
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
+	
 	@Override
 	public String toString() {
 		switch (pc) {

src/main/java/de/srsoftware/web4rail/actions/SetRelay.java

@@ -61,6 +61,11 @@ public class SetRelay extends Action {
 		return super.properties(preForm, formInputs, postForm);
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		if (child == relay) relay = null;
+	}
+	
 	public String toString() {
 		if (isNull(relay)) return "["+t("click here to setup relay")+"]";
 		return t("Set {} to {}",relay,state?relay.stateLabelA:relay.stateLabelB);

src/main/java/de/srsoftware/web4rail/actions/SetSignal.java

@@ -51,7 +51,7 @@ public class SetSignal extends Action {
 	@Override
 	protected Window properties(List<Fieldset> preForm, FormInput formInputs, List<Fieldset> postForm) {
 		Select select = new Select(SIGNAL);
-		for (Signal signal : plan.signals()) {
+		for (Signal signal : BaseClass.listElements(Signal.class)) {
 			Tag option = select.addOption(signal.id(),signal.title());
 			if (signal == this.signal) option.attr("selected", "selected");
 		}
@@ -67,6 +67,11 @@ public class SetSignal extends Action {
 		return super.properties(preForm, formInputs, postForm);
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		if (child == signal) signal = null;
+	}
+		
 	public SetSignal set(Signal sig) {
 		signal = sig;
 		return this;

src/main/java/de/srsoftware/web4rail/actions/SetSpeed.java

@@ -46,6 +46,11 @@ public class SetSpeed extends Action{
 		return super.properties(preForm, formInputs, postForm);
 	}
 		
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
+	
 	@Override
 	public String toString() {
 		return t("Set speed to {} {}",speed,speedUnit);

src/main/java/de/srsoftware/web4rail/actions/ShowText.java

@@ -21,6 +21,11 @@ public class ShowText extends TextAction{
 		return new Label(t("Text to display on clients:")+NBSP);
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
+	
 	@Override
 	public String toString() {
 		return t("Display \"{}\" on clients.",text);

src/main/java/de/srsoftware/web4rail/actions/StopAllTrains.java

@@ -14,4 +14,9 @@ public class StopAllTrains extends Action {
 		Train.list().forEach(train -> train.stopNow());
 		return true;
 	}
+	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
 }

src/main/java/de/srsoftware/web4rail/actions/StopAuto.java

@@ -15,4 +15,8 @@ public class StopAuto extends Action {
 		return true;
 	}
 
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
 }

src/main/java/de/srsoftware/web4rail/actions/TriggerContact.java

@@ -45,6 +45,11 @@ public class TriggerContact extends Action {
 		return super.properties(preForm, formInputs, postForm);
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		if (child == contact) contact = null;
+	}
+	
 	public String toString() {
 		return isSet(contact) ? t("Trigger {}",contact) : "["+t("click here to setup contact")+"]";
 	};

src/main/java/de/srsoftware/web4rail/actions/TurnTrain.java

@@ -16,4 +16,9 @@ public class TurnTrain extends Action{
 		}
 		return false;
 	}
+	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
 }

src/main/java/de/srsoftware/web4rail/conditions/BlockFree.java

@@ -5,6 +5,7 @@ import java.util.List;
 
 import org.json.JSONObject;
 
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Window;
 import de.srsoftware.web4rail.tags.Fieldset;
 import de.srsoftware.web4rail.tiles.Block;
@@ -14,6 +15,11 @@ public class BlockFree extends Condition {
 	private static final String BLOCK = Block.class.getSimpleName();
 	private Block block;
 	
+	private BlockFree block(Block block) {
+		this.block = block;
+		return this;
+	}
+
 	@Override
 	public boolean fulfilledBy(Context context) {
 		return block.isFreeFor(null) != inverted;
@@ -36,17 +42,17 @@ public class BlockFree extends Condition {
 		return super.properties(preForm, formInputs, postForm);
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		if (child == block) block = null;
+	}	
+
 	@Override
 	public String toString() {
 		if (block == null) return t("[Click here to select block!]");
 		return t(inverted ? "Block {} is occupied":"Block {} is free",block);
 	}
 
-	private BlockFree block(Block block) {
-		this.block = block;
-		return this;
-	}
-
 
 	@Override
 	protected Object update(HashMap<String, String> params) {

src/main/java/de/srsoftware/web4rail/conditions/Condition.java

@@ -15,9 +15,7 @@ import de.srsoftware.tools.Tag;
 import de.srsoftware.web4rail.Application;
 import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Plan;
-import de.srsoftware.web4rail.Route;
 import de.srsoftware.web4rail.Window;
-import de.srsoftware.web4rail.actions.ConditionalAction;
 import de.srsoftware.web4rail.tags.Checkbox;
 import de.srsoftware.web4rail.tags.Fieldset;
 import de.srsoftware.web4rail.tags.Label;
@@ -27,9 +25,7 @@ public abstract class Condition extends BaseClass {
 	public static final Logger LOG = LoggerFactory.getLogger(Condition.class);
 	private static final String INVERTED = "inverted";
 	private static final String PREFIX = Condition.class.getPackageName();
-	private static HashMap<Id, Condition> conditions = new HashMap<Id, Condition>();
 	public boolean inverted = false;
-	private Object parent;
 
 	public Condition() {
 		this(new Id());
@@ -37,7 +33,7 @@ public abstract class Condition extends BaseClass {
 	
 	public Condition(Id id) {
 		this.id = id;
-		conditions.put(id, this);
+		register();
 	}	
 	
 	public static Object action(HashMap<String, String> params,Plan plan) {
@@ -47,18 +43,18 @@ public abstract class Condition extends BaseClass {
 		Id cid = Id.from(params);
 		
 		if (isSet(cid)) {		
-			Condition condition = conditions.get(cid);
-			if (condition == null) return t("No condition with id {}!",cid);
+			Condition condition = BaseClass.get(cid);
+			if (isNull(condition)) return t("No condition with id {}!",cid);
 		
 			switch (action) {
 				case ACTION_PROPS:
 					return condition.properties();
 				case ACTION_UPDATE:
 					condition.update(params);
-					return plan.showContext(params);
+					return condition.parent().properties();
 				case ACTION_DROP:
-					condition.drop();
-					return plan.showContext(params);
+					condition.remove();
+					return condition.parent().properties();
 			}
 			return t("Unknown action: {}",action);
 		}
@@ -74,27 +70,18 @@ public abstract class Condition extends BaseClass {
 	
 	private static Object addCondition(HashMap<String, String> params) {
 		String type = params.get(REALM_CONDITION);
-		String context = params.get(CONTEXT);
 		if (isNull(type)) return t("No type supplied to addCondition!");
-		if (isNull(context)) return t("No context supplied to addCondtion!");
+		
+		Id parentId = Id.from(params, PARENT);
+		if (isNull(parentId)) return t("No parent id supplied to addCondition");
+		
+		BaseClass parent = BaseClass.get(parentId);
+		if (isNull(parent)) return t("No condition with id {} found!",parentId);
 		
 		Condition condition = Condition.create(type);
 		if (isNull(condition)) return t("Unknown type \"{}\" of condition!",type);
-		String[] parts = context.split(":");
-		Id contextId = new Id(parts[1]);
-		String realm = parts[0];
-		switch (realm) {
-		case REALM_ROUTE:
-			Route route = plan.route(contextId);
-			if (isNull(route)) return t("Unknown route: {}",contextId);
-			route.add(condition);
-			return route.properties();
 		
-		default:
-			break;
-		}
-		
-		return t("Cannot handle context of type {} in addCondition!");
+		return condition.parent(parent).properties();
 	}
 
 	public static Condition create(String type) {
@@ -107,18 +94,6 @@ public abstract class Condition extends BaseClass {
 		return null;
 	}
 	
-	private void drop() {
-		if (parent instanceof ConditionalAction) {
-			ConditionalAction ca = (ConditionalAction) parent;
-			ca.remove(this);
-		}
-		if (parent instanceof Route) {
-			Route route = (Route) parent;
-			route.remove(this);
-		}
-		conditions.remove(this.id());
-	}
-
 	public abstract boolean fulfilledBy(Context context);
 	
 	public JSONObject json() {
@@ -186,11 +161,6 @@ public abstract class Condition extends BaseClass {
 
 	protected Object update(HashMap<String, String> params) {
 		inverted = "on".equals(params.get(INVERTED));
-		return t("updated {}.",this);
-	}
-
-	public Condition parent(Object parent) {
-		this.parent = parent;
 		return this;
 	}
 }

src/main/java/de/srsoftware/web4rail/conditions/ConditionList.java

@@ -1,35 +1,57 @@
 package de.srsoftware.web4rail.conditions;
 
+import java.util.Iterator;
 import java.util.Vector;
+import java.util.stream.Stream;
 
 import org.json.JSONArray;
 import org.json.JSONObject;
 
-import de.keawe.tools.translations.Translation;
 import de.srsoftware.tools.Tag;
-import de.srsoftware.web4rail.Application;
-import de.srsoftware.web4rail.BaseClass.Context;
-import de.srsoftware.web4rail.BaseClass.Id;
-import de.srsoftware.web4rail.Constants;
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.tags.Button;
 import de.srsoftware.web4rail.tags.Fieldset;
 import de.srsoftware.web4rail.tags.Form;
 import de.srsoftware.web4rail.tags.Input;
 
-public class ConditionList extends Vector<Condition> implements Constants{
+public class ConditionList extends Condition implements Iterable<Condition>{
+	
+	private Vector<Condition> conditions = new Vector<Condition>();
+	
+	public void add(Condition condition) {
+		conditions.add(condition);
+	}
+
+	public void addAll(ConditionList conditions) {
+		this.conditions.addAll(conditions.conditions);		
+	}
 
-	private static final long serialVersionUID = 5826717120751473807L;
 	
 	public boolean fulfilledBy(Context context) {
-		for (Condition condition : this) {
+		for (Condition condition : conditions) {
 			if (!condition.fulfilledBy(context)) return false;
 		}
 		return true;
 	}
 	
-	public JSONArray json() {
+	public boolean isEmpty() {
+		return conditions.isEmpty();
+	}
+	
+	@Override
+	public Iterator<Condition> iterator() {
+		return conditions.iterator();
+	}
+	
+	@Override
+	public JSONObject json() {
+		String cls = getClass().getSimpleName();
+		throw new UnsupportedOperationException(cls+".json() not supported, use "+cls+".jsonArray instead!");
+	}
+
+	public JSONArray jsonArray() {
 		JSONArray json = new JSONArray();
-		for (Condition condition : this) json.put(condition.json());
+		for (Condition condition : conditions) json.put(condition.json());
 		return json;
 	}
 	
@@ -42,39 +64,43 @@ public class ConditionList extends Vector<Condition> implements Constants{
 		if (caption != null) new Tag("p").content(caption).addTo(fieldset);
 		Tag list = new Tag("ul");
 		newConditionForm().addTo(new Tag("li")).addTo(list);
-		forEach(condition -> condition.link("li", condition).addTo(list));
+		conditions.forEach(condition -> condition.link("li", condition).addTo(list));
 		list.addTo(fieldset);
 		return fieldset;
 	}
 
+	public void load(JSONArray arr) {
+		for (int i=0; i<arr.length(); i++) {
+			JSONObject json = arr.getJSONObject(i);
+			Condition condition = Condition.create(json.getString(TYPE));			
+			if (condition != null) {
+				condition.parent(this);
+				conditions.add(condition.load(json));
+			}
+		}
+	}
+
 	private Form newConditionForm() {
 		Form form = new Form("add-condition-form");
 		new Input(REALM, REALM_CONDITION).hideIn(form);
 		new Input(ACTION,ACTION_ADD).hideIn(form);
-		// new Input(CONTEXT,context).hideIn(form); TODO: add context
+		new Input(PARENT,id());
 		Condition.selector().addTo(form);
 		new Button(t("Add condition"), form).addTo(form);
 		return form;
 	}
 	
-	public void load(JSONArray arr) {
-		for (int i=0; i<arr.length(); i++) {
-			JSONObject json = arr.getJSONObject(i);
-			Condition condition = Condition.create(json.getString(TYPE));
-			if (condition != null) add(condition.parent(this).load(json));
-		}
+	public boolean remove(Object condition) {
+		return conditions.remove(condition);
 	}
 	
-	public void removeById(Id cid) {
-		for (Condition condition : this) {
-			if (condition.id().equals(cid)) {
-				remove(condition);
-				break;
-			}
-		}	
+	@Override
+	protected void removeChild(BaseClass child) {
+		conditions.remove(child);
 	}
 
-	private static String t(String tx, Object...fills) {
-		return Translation.get(Application.class, tx, fills);
+
+	public Stream<Condition> stream() {
+		return conditions.stream();
 	}
 }

src/main/java/de/srsoftware/web4rail/conditions/OrCondition.java

@@ -1,46 +1,19 @@
 package de.srsoftware.web4rail.conditions;
 
-import java.util.List;
 import java.util.stream.Collectors;
 
-import org.json.JSONObject;
-
-import de.srsoftware.web4rail.Window;
-import de.srsoftware.web4rail.tags.Fieldset;
-
-public class OrCondition extends Condition{
-	
-	private static final String CONDITIONS = "conditions";
-	private ConditionList conditions = new ConditionList();
+public class OrCondition extends ConditionList{
 	
 	@Override
 	public boolean fulfilledBy(Context context) {
-		for (Condition condition : conditions) {
+		for (Condition condition : this) {
 			if (condition.fulfilledBy(context)) return true;
 		}
 		return false;
 	}
 		
-	@Override
-	public JSONObject json() {
-		return super.json().put(CONDITIONS, conditions.json());
-	}
-	
-	@Override
-	public Condition load(JSONObject json) {
-		super.load(json);
-		if (json.has(CONDITIONS)) conditions.load(json.getJSONArray(CONDITIONS));
-		return this;
-	}
-	
-	@Override
-	protected Window properties(List<Fieldset> preForm, FormInput formInputs, List<Fieldset> postForm) {
-		// add conditions
-		return super.properties(preForm, formInputs, postForm);
-	}
-		
 	@Override
 	public String toString() {
-		return conditions.isEmpty() ? t("Click here to select conditions") : String.join(" "+t("OR")+" ", conditions.stream().map(Object::toString).collect(Collectors.toList()));
+		return isEmpty() ? t("Click here to select conditions") : String.join(" "+t("OR")+" ", stream().map(Object::toString).collect(Collectors.toList()));
 	}
 }

src/main/java/de/srsoftware/web4rail/conditions/PushPullTrain.java

@@ -1,5 +1,7 @@
 package de.srsoftware.web4rail.conditions;
 
+import de.srsoftware.web4rail.BaseClass;
+
 public class PushPullTrain extends Condition {
 	
 	@Override
@@ -7,6 +9,11 @@ public class PushPullTrain extends Condition {
 		return context.train().pushPull != inverted;
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements
+	}
+
 	@Override
 	public String toString() {
 		return t(inverted ? "train is not a push-pull train":"train is a push-pull train") ;

src/main/java/de/srsoftware/web4rail/conditions/TrainHasTag.java

@@ -5,6 +5,7 @@ import java.util.List;
 
 import org.json.JSONObject;
 
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Window;
 import de.srsoftware.web4rail.tags.Fieldset;
 import de.srsoftware.web4rail.tags.Input;
@@ -37,6 +38,11 @@ public class TrainHasTag extends Condition {
 		return super.properties(preForm, formInputs, postForm);
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements
+	}
+	
 	@Override
 	public String toString() {
 		if (tag == null) return t("[Click to setup tag]");

src/main/java/de/srsoftware/web4rail/conditions/TrainLength.java

@@ -6,6 +6,7 @@ import java.util.List;
 import org.json.JSONObject;
 
 import de.srsoftware.tools.Tag;
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Window;
 import de.srsoftware.web4rail.tags.Fieldset;
 import de.srsoftware.web4rail.tags.Input;
@@ -38,6 +39,11 @@ public class TrainLength extends Condition {
 		return super.properties(preForm, formInputs, postForm);
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements
+	}
+	
 	@Override
 	public String toString() {
 		return t(inverted ? "train is longer than {}" : "train is shorter than {}",maxLength) ;

src/main/java/de/srsoftware/web4rail/conditions/TrainSelect.java

@@ -5,6 +5,7 @@ import java.util.List;
 
 import org.json.JSONObject;
 
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Window;
 import de.srsoftware.web4rail.moving.Train;
 import de.srsoftware.web4rail.tags.Fieldset;
@@ -36,6 +37,11 @@ public class TrainSelect extends Condition {
 		return super.properties(preForm, formInputs, postForm);
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		if (child == train) train = null;
+	}
+	
 	@Override
 	public String toString() {
 		if (train == null) return t("[Click here to select train!]");

src/main/java/de/srsoftware/web4rail/moving/Car.java

@@ -214,6 +214,12 @@ public class Car extends BaseClass implements Comparable<Car>{
 		return super.properties(preForm,formInputs,postForm);
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		if (child == train) train = null;
+	}
+
+
 	public static void saveAll(String filename) throws IOException {
 		BufferedWriter file = new BufferedWriter(new FileWriter(filename));
 		for (Entry<Id, Car> entry: cars.entrySet()) file.write(entry.getValue().json()+"\n");

src/main/java/de/srsoftware/web4rail/moving/Train.java

@@ -567,8 +567,14 @@ public class Train extends BaseClass implements Comparable<Train> {
 		} else return t("autopilot not active.");
 	}
 	
-	public void removeFromTrace(Tile tile) {
-		trace.remove(tile);		
+	@Override
+	public void removeChild(BaseClass child) {
+		if (child == route) route = null;
+		if (child == currentBlock) currentBlock = null;
+		if (child == destination) destination = null;
+		cars.remove(child);
+		locos.remove(child);
+		trace.remove(child);
 	}
 	
 	public void reserveNext() {

src/main/java/de/srsoftware/web4rail/tiles/Block.java

@@ -12,6 +12,7 @@ import org.json.JSONArray;
 import org.json.JSONObject;
 
 import de.srsoftware.tools.Tag;
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Connector;
 import de.srsoftware.web4rail.Plan.Direction;
 import de.srsoftware.web4rail.Range;
@@ -233,11 +234,16 @@ public abstract class Block extends StretchableTile implements Comparable<Block>
 		return this;
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements
+	}
+	
 	public static Select selector(Block preselected,Collection<Block> exclude) {
 		if (isNull(exclude)) exclude = new Vector<Block>();
 		Select select = new Select(Block.class.getSimpleName());
 		new Tag("option").attr("value","0").content(t("unset")).addTo(select);
-		for (Block block : plan.blocks()) {
+		for (Block block : BaseClass.listElements(Block.class)) {
 			if (exclude.contains(block)) continue;
 			Tag opt = select.addOption(block.id(), block);
 			if (block == preselected) opt.attr("selected", "selected");

src/main/java/de/srsoftware/web4rail/tiles/Bridge.java

@@ -7,6 +7,7 @@ import java.util.Map;
 import org.json.JSONObject;
 
 import de.srsoftware.tools.Tag;
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Connector;
 import de.srsoftware.web4rail.Route;
 import de.srsoftware.web4rail.Window;
@@ -100,6 +101,12 @@ public abstract class Bridge extends Tile {
 		return t("Click other bridge to connect to!");
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		if (child == counterpart) counterpart = null;
+		plan.place(this);
+	}
+	
 	@Override
 	public Tag tag(Map<String, Object> replacements) throws IOException {
 		Tag tag = super.tag(replacements);

src/main/java/de/srsoftware/web4rail/tiles/Contact.java

@@ -11,6 +11,7 @@ import java.util.TreeMap;
 import org.json.JSONObject;
 
 import de.srsoftware.tools.Tag;
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Window;
 import de.srsoftware.web4rail.actions.ActionList;
 import de.srsoftware.web4rail.tags.Fieldset;
@@ -165,6 +166,11 @@ public class Contact extends Tile{
 		return super.properties(preForm, formInputs, postForm);
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		if (child == actions) actions = null;
+	}
+	
 	public static Select selector(Contact preselect) {
 		TreeMap<String,Contact> sortedSet = new TreeMap<String, Contact>(); // Map from Name to Contact
 		for (Contact contact : contactsById.values()) sortedSet.put(contact.toString(), contact);

src/main/java/de/srsoftware/web4rail/tiles/Cross.java

@@ -2,9 +2,15 @@ package de.srsoftware.web4rail.tiles;
 
 import java.util.Map;
 
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Connector;
 import de.srsoftware.web4rail.Plan.Direction;
 
 public abstract class Cross extends Tile {
 	public abstract Map<Connector,Turnout.State> offsetConnections(Direction from);
+	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
 }

src/main/java/de/srsoftware/web4rail/tiles/CrossPlus.java

@@ -4,6 +4,7 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Connector;
 import de.srsoftware.web4rail.Plan.Direction;
 import de.srsoftware.web4rail.tiles.Turnout.State;
@@ -31,4 +32,9 @@ public class CrossPlus extends Tile{
 	public List<Direction> possibleDirections() {
 		return List.of(Direction.EAST,Direction.WEST,Direction.NORTH,Direction.SOUTH);
 	}	
+	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
 }

src/main/java/de/srsoftware/web4rail/tiles/DiagES.java

@@ -3,6 +3,7 @@ package de.srsoftware.web4rail.tiles;
 import java.util.HashMap;
 import java.util.Map;
 
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Connector;
 import de.srsoftware.web4rail.Plan.Direction;
 import de.srsoftware.web4rail.tiles.Turnout.State;
@@ -21,4 +22,9 @@ public class DiagES extends Tile{
 				return new HashMap<>();
 		}
 	}
+	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
 }

src/main/java/de/srsoftware/web4rail/tiles/DiagNE.java

@@ -3,6 +3,7 @@ package de.srsoftware.web4rail.tiles;
 import java.util.HashMap;
 import java.util.Map;
 
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Connector;
 import de.srsoftware.web4rail.Plan.Direction;
 import de.srsoftware.web4rail.tiles.Turnout.State;
@@ -21,4 +22,9 @@ public class DiagNE extends Tile{
 				return new HashMap<>();
 		}
 	}
+	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
 }

src/main/java/de/srsoftware/web4rail/tiles/DiagSW.java

@@ -3,6 +3,7 @@ package de.srsoftware.web4rail.tiles;
 import java.util.HashMap;
 import java.util.Map;
 
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Connector;
 import de.srsoftware.web4rail.Plan.Direction;
 import de.srsoftware.web4rail.tiles.Turnout.State;
@@ -20,4 +21,9 @@ public class DiagSW extends Tile{
 				return new HashMap<>();
 		}
 	}
+	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
 }

src/main/java/de/srsoftware/web4rail/tiles/DiagWN.java

@@ -3,6 +3,7 @@ package de.srsoftware.web4rail.tiles;
 import java.util.HashMap;
 import java.util.Map;
 
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Connector;
 import de.srsoftware.web4rail.Plan.Direction;
 import de.srsoftware.web4rail.tiles.Turnout.State;
@@ -22,4 +23,10 @@ public class DiagWN extends Tile{
 				return new HashMap<>();
 		}
 	}
+	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
+
 }

src/main/java/de/srsoftware/web4rail/tiles/EndE.java

@@ -1,4 +1,10 @@
 package de.srsoftware.web4rail.tiles;
 
+import de.srsoftware.web4rail.BaseClass;
+
 public class EndE extends Tile{
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
 }

src/main/java/de/srsoftware/web4rail/tiles/EndN.java

@@ -1,4 +1,11 @@
 package de.srsoftware.web4rail.tiles;
 
+import de.srsoftware.web4rail.BaseClass;
+
 public class EndN extends Tile{
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
+
 }

src/main/java/de/srsoftware/web4rail/tiles/EndS.java

@@ -1,4 +1,10 @@
 package de.srsoftware.web4rail.tiles;
 
+import de.srsoftware.web4rail.BaseClass;
+
 public class EndS extends Tile{
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
 }

src/main/java/de/srsoftware/web4rail/tiles/EndW.java

@@ -1,3 +1,10 @@
 package de.srsoftware.web4rail.tiles;
 
-public class EndW extends Tile{}
+import de.srsoftware.web4rail.BaseClass;
+
+public class EndW extends Tile{
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
+}

src/main/java/de/srsoftware/web4rail/tiles/Eraser.java

@@ -1,5 +1,10 @@
 package de.srsoftware.web4rail.tiles;
 
-public class Eraser extends Tile {
+import de.srsoftware.web4rail.BaseClass;
 
+public class Eraser extends Tile {
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
 }

src/main/java/de/srsoftware/web4rail/tiles/Relay.java

@@ -11,6 +11,7 @@ import java.util.concurrent.TimeoutException;
 import org.json.JSONObject;
 
 import de.srsoftware.tools.Tag;
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Command;
 import de.srsoftware.web4rail.Command.Reply;
 import de.srsoftware.web4rail.Device;
@@ -40,7 +41,6 @@ public class Relay extends Tile implements Device{
 	private String name = t("Relay");
 	protected boolean state = true;
 	
-	private static final HashMap<Id,Relay> relays = new HashMap<Id, Relay>();
 	public static final boolean STATE_A = true,STATE_B=false;
 	private static final String LABEL_A = "label_a";
 	private static final String LABEL_B = "label_b";
@@ -125,7 +125,6 @@ public class Relay extends Tile implements Device{
 	@Override
 	public Tile position(int x, int y) {
 		super.position(x, y);
-		relays.put(id(), this);
 		return this;
 	}
 	
@@ -161,6 +160,11 @@ public class Relay extends Tile implements Device{
 		}		
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// TODO Auto-generated method stub
+	}
+	
 	public Relay setLabel(boolean state, String tx) {
 		if (state) {
 			stateLabelA = tx;
@@ -235,19 +239,11 @@ public class Relay extends Tile implements Device{
 		return super.update(params);
 	}
 
-	public static Collection<Relay> list() {
-		return relays.values();
-	}
-
-	public static Relay get(Id relayId) {
-		return relays.get(relayId);
-	}
-
 	public static Select selector(Relay preselected, Collection<Relay> exclude) {
 		if (isNull(exclude)) exclude = new Vector<Relay>();
 		Select select = new Select(Relay.class.getSimpleName());
 		new Tag("option").attr("value","0").content(t("unset")).addTo(select);
-		for (Relay relay : Relay.list()) {			
+		for (Relay relay : BaseClass.listElements(Relay.class)) {			
 			if (exclude.contains(relay)) continue;
 			Tag opt = select.addOption(relay.id, relay);
 			if (relay == preselected) opt.attr("selected", "selected");

src/main/java/de/srsoftware/web4rail/tiles/Shadow.java

@@ -4,6 +4,7 @@ import java.io.IOException;
 import java.util.Map;
 
 import de.srsoftware.tools.Tag;
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Connector;
 import de.srsoftware.web4rail.Plan.Direction;
 import de.srsoftware.web4rail.tiles.Turnout.State;
@@ -28,6 +29,14 @@ public class Shadow extends Tile{
 		return overlay;
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		if (child == overlay) {
+			overlay = null;
+			remove();
+		}
+	}
+	
 	@Override
 	public Tag tag(Map<String, Object> replacements) throws IOException {
 		Tag tag = super.tag(replacements);

src/main/java/de/srsoftware/web4rail/tiles/Signal.java

@@ -7,6 +7,7 @@ import java.util.TreeSet;
 import java.util.Vector;
 
 import de.srsoftware.tools.Tag;
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Plan.Direction;
 
 public abstract class Signal extends Tile implements Comparable<Signal>{
@@ -38,6 +39,11 @@ public abstract class Signal extends Tile implements Comparable<Signal>{
 	
 	public abstract boolean isAffectedFrom(Direction dir);
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
+
 	public boolean state(String state) {
 		this.state = state;
 		plan.place(this);

src/main/java/de/srsoftware/web4rail/tiles/StraightH.java

@@ -4,6 +4,7 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Connector;
 import de.srsoftware.web4rail.Plan.Direction;
 import de.srsoftware.web4rail.tiles.Turnout.State;
@@ -24,17 +25,22 @@ public class StraightH extends StretchableTile{
 	}
 	
 	@Override
-	public int width() {
-		return stretch;
+	public List<Direction> possibleDirections() {
+		return List.of(Direction.EAST,Direction.WEST);
 	}
 
 	@Override
-	public List<Direction> possibleDirections() {
-		return List.of(Direction.EAST,Direction.WEST);
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
 	}
 	
 	@Override
 	protected String stretchType() {
 		return t("Width");
 	}
+	
+	@Override
+	public int width() {
+		return stretch;
+	}
 }

src/main/java/de/srsoftware/web4rail/tiles/StraightV.java

@@ -4,6 +4,7 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Connector;
 import de.srsoftware.web4rail.Plan.Direction;
 import de.srsoftware.web4rail.tiles.Turnout.State;
@@ -33,6 +34,11 @@ public class StraightV extends StretchableTile{
 		return List.of(Direction.NORTH,Direction.SOUTH);
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
+	
 	@Override
 	protected String stretchType() {
 		return t("Height");

src/main/java/de/srsoftware/web4rail/tiles/TextDisplay.java

@@ -11,6 +11,7 @@ import java.util.Vector;
 import org.json.JSONObject;
 
 import de.srsoftware.tools.Tag;
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Window;
 import de.srsoftware.web4rail.tags.Fieldset;
 import de.srsoftware.web4rail.tags.Input;
@@ -44,15 +45,19 @@ public class TextDisplay extends StretchableTile {
 		return super.properties(preForm, formInputs, postForm);
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
+
 	public static Select selector(TextDisplay preselected,Collection<TextDisplay> exclude) {
 		if (isNull(exclude)) exclude = new Vector<TextDisplay>();
 		Select select = new Select(TextDisplay.class.getSimpleName());
 		new Tag("option").attr("value","0").content(t("unset")).addTo(select);
-		for (Tile tile : plan.tiles.values()) {
-			if (!(tile instanceof TextDisplay)) continue;
-			if (exclude.contains(tile)) continue;
-			Tag opt = select.addOption(tile.id(), tile);
-			if (tile == preselected) opt.attr("selected", "selected");
+		for (TextDisplay display : BaseClass.listElements(TextDisplay.class)) {
+			if (exclude.contains(display)) continue;
+			Tag opt = select.addOption(display.id(), display);
+			if (display == preselected) opt.attr("selected", "selected");
 		}
 		return select;
 	}

src/main/java/de/srsoftware/web4rail/tiles/Tile.java

@@ -251,8 +251,10 @@ public abstract class Tile extends BaseClass{
 		return super.properties(preForm, formInputs, postForm);
 	}
 	
-	public void remove(Route route) {
-		routes.remove(route);
+	@Override
+	public BaseClass remove() {
+		plan.stream("remove "+id());
+		return super.remove();
 	}
 	
 	private static String replace(String line, Entry<String, Object> replacement) {
@@ -280,9 +282,9 @@ public abstract class Tile extends BaseClass{
 		return routes;
 	}
 	
-	public static void saveAll(HashMap<Id, Tile> tiles ,String filename) throws IOException {
+	public static void saveAll(String filename) throws IOException {
 		BufferedWriter file = new BufferedWriter(new FileWriter(filename));
-		for (Tile tile : tiles.values()) {
+		for (Tile tile : BaseClass.listElements(Tile.class)) {
 			if (isNull(tile) || tile instanceof Shadow) continue;
 			file.append(tile.json()+"\n");
 		}

src/main/java/de/srsoftware/web4rail/tiles/Turnout.java

@@ -9,6 +9,7 @@ import java.util.concurrent.TimeoutException;
 import org.json.JSONObject;
 
 import de.srsoftware.tools.Tag;
+import de.srsoftware.web4rail.BaseClass;
 import de.srsoftware.web4rail.Command;
 import de.srsoftware.web4rail.Command.Reply;
 import de.srsoftware.web4rail.Device;
@@ -139,6 +140,11 @@ public abstract class Turnout extends Tile implements Device{
 		}		
 	}
 	
+	@Override
+	protected void removeChild(BaseClass child) {
+		// this class has no child elements		
+	}
+	
 	public State state() {
 		return state;
 	}

src/main/java/de/srsoftware/web4rail/tiles/TurnoutL.java

@@ -8,7 +8,7 @@ import de.srsoftware.web4rail.Window;
 import de.srsoftware.web4rail.tags.Fieldset;
 import de.srsoftware.web4rail.tags.Input;
 
-public class TurnoutL extends Turnout {
+public abstract class TurnoutL extends Turnout {
 
 	private static final String LEFT = "left";
 

src/main/java/de/srsoftware/web4rail/tiles/TurnoutR.java

@@ -8,7 +8,7 @@ import de.srsoftware.web4rail.Window;
 import de.srsoftware.web4rail.tags.Fieldset;
 import de.srsoftware.web4rail.tags.Input;
 
-public class TurnoutR extends Turnout {
+public abstract class TurnoutR extends Turnout {
 	
 	private static final String RIGHT = "right";