Further development of split-road feature; refactoring of change-handling

Logic/Actors/ChangeToElementsActor.ts

@@ -0,0 +1,36 @@
+import {ElementStorage} from "../ElementStorage";
+import {Changes} from "../Osm/Changes";
+
+export default class ChangeToElementsActor {
+    constructor(changes: Changes, allElements: ElementStorage) {
+        changes.pendingChanges.addCallbackAndRun(changes => {
+            for (const change of changes) {
+                const id = change.type + "/" + change.id;
+                if (!allElements.has(id)) {
+continue; // Will be picked up later on
+                }
+                const src = allElements.getEventSourceById(id)
+
+                let changed = false;
+                for (const kv of change.tags ?? []) {
+                    // Apply tag changes and ping the consumers
+                    const k = kv.k
+                    let v = kv.v
+                    if (v === "") {
+                        v = undefined;
+                    }
+                    if (src.data[k] === v) {
+                        continue
+                    }
+                    changed = true;
+                    src.data[k] = v;
+                }
+                if (changed) {
+                    src.ping()
+                }
+
+
+            }
+        })
+    }
+}

Logic/Actors/PendingChangesUploader.ts

@@ -9,7 +9,7 @@ export default class PendingChangesUploader {
     constructor(changes: Changes, selectedFeature: UIEventSource<any>) {
         const self = this;
         this.lastChange = new Date();
-        changes.pending.addCallback(() => {
+        changes.pendingChanges.addCallback(() => {
             self.lastChange = new Date();
 
             window.setTimeout(() => {
@@ -54,7 +54,7 @@ export default class PendingChangesUploader {
 
 
         function onunload(e) {
-            if (changes.pending.data.length == 0) {
+            if(changes.pendingChanges.data.length == 0){
                 return;
             }
             changes.flushChanges("onbeforeunload - probably closing or something similar");

Logic/FeatureSource/ChangeApplicator.ts

@@ -0,0 +1,138 @@
+import FeatureSource from "./FeatureSource";
+import {UIEventSource} from "../UIEventSource";
+import {Changes} from "../Osm/Changes";
+import {ChangeDescription} from "../Osm/Actions/ChangeDescription";
+import {Utils} from "../../Utils";
+import {OsmNode, OsmRelation, OsmWay} from "../Osm/OsmObject";
+
+/**
+ * Applies changes from 'Changes' onto a featureSource
+ */
+export default class ChangeApplicator implements FeatureSource {
+    public readonly features: UIEventSource<{ feature: any; freshness: Date }[]>;
+    public readonly name: string;
+
+    constructor(source: FeatureSource, changes: Changes) {
+
+        this.name = "ChangesApplied(" + source.name + ")"
+        this.features = source.features
+
+        source.features.addCallbackAndRunD(features => {
+            ChangeApplicator.ApplyChanges(features, changes.pendingChanges.data)
+        })
+
+        changes.pendingChanges.addCallbackAndRunD(changes => {
+            ChangeApplicator.ApplyChanges(source.features.data, changes)
+            source.features.ping()
+        })
+
+
+    }
+
+
+    private static ApplyChanges(features: { feature: any, freshness: Date }[], cs: ChangeDescription[]) {
+        if (cs.length === 0 || features === undefined) {
+            return features;
+        }
+
+        const changesPerId: Map<string, ChangeDescription[]> = new Map<string, ChangeDescription[]>()
+        for (const c of cs) {
+            const id = c.type + "/" + c.id
+            if (!changesPerId.has(id)) {
+                changesPerId.set(id, [])
+            }
+            changesPerId.get(id).push(c)
+        }
+
+
+        const now = new Date()
+
+        function add(feature) {
+            features.push({
+                feature: feature,
+                freshness: now
+            })
+        }
+
+        // First, create the new features - they have a negative ID
+        // We don't set the properties yet though
+        changesPerId.forEach(cs => {
+            cs.forEach(change => {
+                if (change.id >= 0) {
+                    return; // Nothing to do here, already created
+                }
+
+
+                try {
+
+                    switch (change.type) {
+                        case "node":
+                            const n = new OsmNode(change.id)
+                            n.lat = change.changes["lat"]
+                            n.lon = change.changes["lon"]
+                            const geojson = n.asGeoJson()
+                            add(geojson)
+                            break;
+                        case "way":
+                            const w = new OsmWay(change.id)
+                            w.nodes = change.changes["nodes"]
+                            add(w.asGeoJson())
+                            break;
+                        case "relation":
+                            const r = new OsmRelation(change.id)
+                            r.members = change.changes["members"]
+                            add(r.asGeoJson())
+                            break;
+                    }
+
+                } catch (e) {
+                    console.error(e)
+                }
+            })
+        })
+
+
+        for (const feature of features) {
+            const id = feature.feature.properties.id;
+            const f = feature.feature;
+            if (!changesPerId.has(id)) {
+                continue;
+            }
+
+
+            const changed = {}
+            // Copy all the properties
+            Utils.Merge(f, changed)
+            // play the changes onto the copied object
+
+            for (const change of changesPerId.get(id)) {
+                for (const kv of change.tags ?? []) {
+                    // Apply tag changes and ping the consumers
+                    const k = kv.k
+                    let v = kv.v
+                    if (v === "") {
+                        v = undefined;
+                    }
+                    f.properties[k] = v;
+                }
+
+                // Apply other changes to the object
+                if (change.changes !== undefined) {
+                    switch (change.type) {
+                        case "node":
+                            // @ts-ignore
+                            const coor: { lat, lon } = change.changes;
+                            f.geometry.coordinates = [[coor.lon, coor.lat]]
+                            break;
+                        case "way":
+                            f.geometry.coordinates = change.changes["locations"]
+                            break;
+                        case "relation":
+                            console.error("Changes to relations are not yet supported")
+                            break;
+                    }
+                }
+            }
+        }
+    }
+}

Logic/FeatureSource/FeaturePipeline.ts

@@ -13,6 +13,8 @@ import Loc from "../../Models/Loc";
 import GeoJsonSource from "./GeoJsonSource";
 import MetaTaggingFeatureSource from "./MetaTaggingFeatureSource";
 import RegisteringFeatureSource from "./RegisteringFeatureSource";
+import {Changes} from "../Osm/Changes";
+import ChangeApplicator from "./ChangeApplicator";
 
 export default class FeaturePipeline implements FeatureSource {
 
@@ -21,10 +23,10 @@ export default class FeaturePipeline implements FeatureSource {
     public readonly name = "FeaturePipeline"
 
     constructor(flayers: UIEventSource<{ isDisplayed: UIEventSource<boolean>, layerDef: LayerConfig }[]>,
+                changes: Changes,
                 updater: FeatureSource,
                 fromOsmApi: FeatureSource,
                 layout: UIEventSource<LayoutConfig>,
-                newPoints: FeatureSource,
                 locationControl: UIEventSource<Loc>,
                 selectedElement: UIEventSource<any>) {
 
@@ -40,13 +42,16 @@ export default class FeaturePipeline implements FeatureSource {
                     new MetaTaggingFeatureSource(allLoadedFeatures,
                         new FeatureDuplicatorPerLayer(flayers,
                             new RegisteringFeatureSource(
-                                updater)
+                                new ChangeApplicator(
+                                    updater, changes
+                                ))
                         )), layout));
 
         const geojsonSources: FeatureSource [] = GeoJsonSource
             .ConstructMultiSource(flayers.data, locationControl)
             .map(geojsonSource => {
-                let source = new RegisteringFeatureSource(new FeatureDuplicatorPerLayer(flayers, geojsonSource));
+                let source = new RegisteringFeatureSource(new FeatureDuplicatorPerLayer(flayers, 
+                    new ChangeApplicator(geojsonSource, changes)));
                 if(!geojsonSource.isOsmCache){
                     source = new MetaTaggingFeatureSource(allLoadedFeatures, source, updater.features);
                 }
@@ -54,25 +59,19 @@ export default class FeaturePipeline implements FeatureSource {
             });
 
         const amendedLocalStorageSource =
-            new RememberingSource(new RegisteringFeatureSource(new FeatureDuplicatorPerLayer(flayers, new LocalStorageSource(layout))
+            new RememberingSource(new RegisteringFeatureSource(new FeatureDuplicatorPerLayer(flayers,new ChangeApplicator( new LocalStorageSource(layout), changes))
             ));
 
-        newPoints = new MetaTaggingFeatureSource(allLoadedFeatures,
-            new FeatureDuplicatorPerLayer(flayers,
-                new RegisteringFeatureSource(newPoints)));
-
         const amendedOsmApiSource = new RememberingSource(
             new MetaTaggingFeatureSource(allLoadedFeatures,
                 new FeatureDuplicatorPerLayer(flayers,
-
-                    new RegisteringFeatureSource(fromOsmApi))));
+                    new RegisteringFeatureSource(new ChangeApplicator(fromOsmApi, changes)))));
 
         const merged =
             new FeatureSourceMerger([
                 amendedOverpassSource,
                 amendedOsmApiSource,
                 amendedLocalStorageSource,
-                newPoints,
                 ...geojsonSources
             ]);
 

Logic/Osm/Actions/Action.ts

@@ -1,7 +0,0 @@
-/**
- * An action is a change to the OSM-database
- * It will generate some new/modified/deleted objects, which are all bundled by the 'changes'-object
- */
-export default interface Action {
-    
-}

Logic/Osm/Actions/ChangeDescription.ts

@@ -0,0 +1,30 @@
+export interface ChangeDescription {
+
+    type: "node" | "way" | "relation",
+    /**
+     * Negative for a new objects
+     */
+    id: number,
+    /*
+ v = "" or v = undefined to erase this tag
+ */
+    tags?: { k: string, v: string }[],
+
+    changes?: {
+        lat: number,
+        lon: number
+    } | {
+        // Coordinates are only used for rendering
+        locations: [number, number][]
+        nodes: number[],
+    } | {
+        members: { type: "node" | "way" | "relation", ref: number, role: string }[]
+    }
+
+    /*
+    Set to delete the object
+     */
+    doDelete?: boolean
+
+
+}

Logic/Osm/Actions/ChangeTagAction.ts

@@ -0,0 +1,52 @@
+import OsmChangeAction from "./OsmChangeAction";
+import {Changes} from "../Changes";
+import {ChangeDescription} from "./ChangeDescription";
+import {TagsFilter} from "../../Tags/TagsFilter";
+
+export default class ChangeTagAction extends OsmChangeAction {
+    private readonly _elementId: string;
+    private readonly _tagsFilter: TagsFilter;
+    private readonly _currentTags: any;
+
+    constructor(elementId: string, tagsFilter: TagsFilter, currentTags: any) {
+        super();
+        this._elementId = elementId;
+        this._tagsFilter = tagsFilter;
+        this._currentTags = currentTags;
+    }
+
+    /**
+     * Doublechecks that no stupid values are added
+     */
+    private static checkChange(kv: { k: string, v: string }): { k: string, v: string } {
+        const key = kv.k;
+        const value = kv.v;
+        if (key === undefined || key === null) {
+            console.log("Invalid key");
+            return undefined;
+        }
+        if (value === undefined || value === null) {
+            console.log("Invalid value for ", key);
+            return undefined;
+        }
+
+        if (key.startsWith(" ") || value.startsWith(" ") || value.endsWith(" ") || key.endsWith(" ")) {
+            console.warn("Tag starts with or ends with a space - trimming anyway")
+        }
+
+        return {k: key.trim(), v: value.trim()};
+    }
+
+    Perform(changes: Changes): ChangeDescription [] {
+        const changedTags: { k: string, v: string }[] = this._tagsFilter.asChange(this._currentTags).map(ChangeTagAction.checkChange)
+        const typeId = this._elementId.split("/")
+        const type = typeId[0]
+        const id = Number(typeId  [1])
+        return [{
+            // @ts-ignore
+            type: type,
+            id: id,
+            tags: changedTags
+        }]
+    }
+}

Logic/Osm/Actions/CreateNewNodeAction.ts

@@ -0,0 +1,44 @@
+import {Tag} from "../../Tags/Tag";
+import OsmChangeAction from "./OsmChangeAction";
+import {Changes} from "../Changes";
+import {ChangeDescription} from "./ChangeDescription";
+import {And} from "../../Tags/And";
+
+export default class CreateNewNodeAction implements OsmChangeAction {
+
+    private readonly _basicTags: Tag[];
+    private readonly _lat: number;
+    private readonly _lon: number;
+
+    constructor(basicTags: Tag[], lat: number, lon: number) {
+        this._basicTags = basicTags;
+        this._lat = lat;
+        this._lon = lon;
+    }
+
+    Perform(changes: Changes): ChangeDescription[] {
+        const id = changes.getNewID()
+        const properties = {
+            id: "node/" + id
+        }
+        for (const kv of this._basicTags) {
+            if (typeof kv.value !== "string") {
+                throw "Invalid value: don't use a regex in a preset"
+            }
+            properties[kv.key] = kv.value;
+        }
+
+        return [{
+            tags: new And(this._basicTags).asChange(properties),
+            type: "node",
+            id: id,
+            changes:{
+                lat: this._lat,
+                lon: this._lon
+            }
+        }]
+
+    }
+
+
+}

Logic/Osm/Actions/DeleteAction.ts

@@ -1,9 +1,9 @@
-import {UIEventSource} from "../UIEventSource";
-import {Translation} from "../../UI/i18n/Translation";
-import Translations from "../../UI/i18n/Translations";
-import {OsmObject} from "./OsmObject";
-import State from "../../State";
-import Constants from "../../Models/Constants";
+import {UIEventSource} from "../../UIEventSource";
+import {Translation} from "../../../UI/i18n/Translation";
+import State from "../../../State";
+import {OsmObject} from "../OsmObject";
+import Translations from "../../../UI/i18n/Translations";
+import Constants from "../../../Models/Constants";
 
 export default class DeleteAction {
 
@@ -30,7 +30,7 @@ export default class DeleteAction {
      * Does actually delete the feature; returns the event source 'this.isDeleted'
      * If deletion is not allowed, triggers the callback instead
      */
-    public DoDelete(reason: string, onNotAllowed : () => void): UIEventSource<boolean> {
+    public DoDelete(reason: string, onNotAllowed : () => void): void {
         const isDeleted = this.isDeleted
         const self = this;
         let deletionStarted = false;
@@ -75,8 +75,6 @@ export default class DeleteAction {
 
             }
         )
-
-        return isDeleted;
     }
 
     /**

Logic/Osm/Actions/OsmChangeAction.ts

@@ -0,0 +1,16 @@
+/**
+ * An action is a change to the OSM-database
+ * It will generate some new/modified/deleted objects, which are all bundled by the 'changes'-object
+ */
+import {Changes} from "../Changes";
+import {ChangeDescription} from "./ChangeDescription";
+
+export default abstract class OsmChangeAction {
+
+
+
+    public abstract Perform(changes: Changes): ChangeDescription[]
+    
+    
+    
+}

Logic/Osm/Actions/RelationSplitlHandler.ts

@@ -0,0 +1,20 @@
+/**
+ * The logic to handle relations after a way within 
+ */
+import OsmChangeAction from "./OsmChangeAction";
+import {Changes} from "../Changes";
+import {ChangeDescription} from "./ChangeDescription";
+import {OsmRelation, OsmWay} from "../OsmObject";
+
+export default class RelationSplitlHandler extends OsmChangeAction{
+
+    constructor(partOf: OsmRelation[], newWayIds: number[], originalNodes: number[]) {
+        super()
+    }
+
+    Perform(changes: Changes): ChangeDescription[] {
+        return [];
+    }
+
+
+}

Logic/Osm/Actions/SplitAction.ts

@@ -0,0 +1,236 @@
+import {OsmRelation, OsmWay} from "../OsmObject";
+import {Changes} from "../Changes";
+import {GeoOperations} from "../../GeoOperations";
+import OsmChangeAction from "./OsmChangeAction";
+import {ChangeDescription} from "./ChangeDescription";
+import RelationSplitlHandler from "./RelationSplitlHandler";
+
+interface SplitInfo {
+    originalIndex?: number, // or negative for new elements
+    lngLat: [number, number],
+    doSplit: boolean
+}
+
+export default class SplitAction extends OsmChangeAction {
+    private readonly roadObject: any;
+    private readonly osmWay: OsmWay;
+    private _partOf: OsmRelation[];
+    private readonly _splitPoints: any[];
+
+    constructor(osmWay: OsmWay, wayGeoJson: any, partOf: OsmRelation[], splitPoints: any[]) {
+        super()
+        this.osmWay = osmWay;
+        this.roadObject = wayGeoJson;
+        this._partOf = partOf;
+        this._splitPoints = splitPoints;
+    }
+
+    private static SegmentSplitInfo(splitInfo: SplitInfo[]): SplitInfo[][] {
+        const wayParts = []
+        let currentPart = []
+        for (const splitInfoElement of splitInfo) {
+            currentPart.push(splitInfoElement)
+
+            if (splitInfoElement.doSplit) {
+                // We have to do a split!
+                // We add the current index to the currentParts, flush it and add it again
+                wayParts.push(currentPart)
+                currentPart = [splitInfoElement]
+            }
+        }
+        wayParts.push(currentPart)
+        return wayParts.filter(wp => wp.length > 0)
+    }
+
+    Perform(changes: Changes): ChangeDescription[] {
+        const splitPoints = this._splitPoints
+        // We mark the new split points with a new id
+        console.log(splitPoints)
+        for (const splitPoint of splitPoints) {
+            splitPoint.properties["_is_split_point"] = true
+        }
+
+
+        const self = this;
+        const partOf = this._partOf
+        const originalElement = this.osmWay
+        const originalNodes = this.osmWay.nodes;
+
+        // First, calculate splitpoints and remove points close to one another
+        const splitInfo = self.CalculateSplitCoordinates(splitPoints)
+        // Now we have a list with e.g. 
+        // [ { originalIndex: 0}, {originalIndex: 1, doSplit: true}, {originalIndex: 2}, {originalIndex: undefined, doSplit: true}, {originalIndex: 3}]
+
+        // Lets change 'originalIndex' to the actual node id first:
+        for (const element of splitInfo) {
+            if (element.originalIndex >= 0) {
+                element.originalIndex = originalElement.nodes[element.originalIndex]
+            } else {
+                element.originalIndex = changes.getNewID();
+            }
+        }
+
+        // Next up is creating actual parts from this
+        const wayParts: SplitInfo[][] = SplitAction.SegmentSplitInfo(splitInfo);
+console.log("WayParts", wayParts, "by", splitInfo)
+        // Allright! At this point, we have our new ways!
+        // Which one is the longest of them (and can keep the id)?
+
+        let longest = undefined;
+        for (const wayPart of wayParts) {
+            if (longest === undefined) {
+                longest = wayPart;
+                continue
+            }
+            if (wayPart.length > longest.length) {
+                longest = wayPart
+            }
+        }
+
+        const changeDescription: ChangeDescription[] = []
+        // Let's create the new points as needed
+        for (const element of splitInfo) {
+            if (element.originalIndex >= 0) {
+                continue;
+            }
+            changeDescription.push({
+                type: "node",
+                id: element.originalIndex,
+                changes:{
+                    lon:  element.lngLat[0],
+                    lat: element.lngLat[1]
+                }
+            })
+        }
+
+        const newWayIds: number[] = []
+        // Lets create OsmWays based on them
+        for (const wayPart of wayParts) {
+
+            let isOriginal = wayPart === longest
+            if (isOriginal) {
+                // We change the actual element!
+                changeDescription.push({
+                    type:"way",
+                    id: originalElement.id,
+                    changes:{
+                        locations: wayPart.map(p => p.lngLat),
+                        nodes:  wayPart.map(p => p.originalIndex)
+                    }
+                })
+            } else {
+                let id = changes.getNewID();
+                newWayIds.push(id)
+                
+                const kv = []
+                for (const k in originalElement.tags) {
+                    if(!originalElement.tags.hasOwnProperty(k)){
+                        continue
+                    }
+                    kv .push({k: k, v: originalElement.tags[k]})
+                }
+                changeDescription.push({
+                    type:"way",
+                    id:id,
+                    tags: kv,
+                    changes:{
+                        locations: wayPart.map(p => p.lngLat),
+                        nodes:  wayPart.map(p => p.originalIndex)
+                    }
+                })
+            }
+
+        }
+
+        // At last, we still have to check that we aren't part of a relation...
+        // At least, the order of the ways is identical, so we can keep the same roles
+        changeDescription.push(...new RelationSplitlHandler(partOf, newWayIds, originalNodes).Perform(changes))
+
+        // And we have our objects!
+        // Time to upload
+
+      return changeDescription
+    }
+
+    /**
+     * Calculates the actual points to split
+     * If another point is closer then ~5m, we reuse that point
+     */
+    private CalculateSplitCoordinates(
+        splitPoints: any[],
+        toleranceInM = 5): SplitInfo[] {
+
+        const allPoints = [...splitPoints];
+        // We have a bunch of coordinates here: [ [lat, lon], [lat, lon], ...] ...
+        const originalPoints: [number, number][] = this.roadObject.geometry.coordinates
+        // We project them onto the line (which should yield pretty much the same point
+        for (let i = 0; i < originalPoints.length; i++) {
+            let originalPoint = originalPoints[i];
+            let projected = GeoOperations.nearestPoint(this.roadObject, originalPoint)
+            projected.properties["_is_split_point"] = false
+            projected.properties["_original_index"] = i
+            allPoints.push(projected)
+        }
+        // At this point, we have a list of both the split point and the old points, with some properties to discriminate between them
+        // We sort this list so that the new points are at the same location
+        allPoints.sort((a, b) => a.properties.location - b.properties.location)
+
+        // When this is done, we check that no now point is too close to an already existing point and no very small segments get created
+
+     /*   for (let i = allPoints.length - 1; i > 0; i--) {
+
+            const point = allPoints[i];
+            if (point.properties._original_index !== undefined) {
+                // This point is already in OSM - we have to keep it!
+                continue;
+            }
+
+            if (i != allPoints.length - 1) {
+                const prevPoint = allPoints[i + 1]
+                const diff = Math.abs(point.properties.location - prevPoint.properties.location) * 1000
+                if (diff <= toleranceInM) {
+                    // To close to the previous point! We delete this point...
+                    allPoints.splice(i, 1)
+                    // ... and mark the previous point as a split point
+                    prevPoint.properties._is_split_point = true
+                    continue;
+                }
+            }
+
+            if (i > 0) {
+                const nextPoint = allPoints[i - 1]
+                const diff = Math.abs(point.properties.location - nextPoint.properties.location) * 1000
+                if (diff <= toleranceInM) {
+                    // To close to the next point! We delete this point...
+                    allPoints.splice(i, 1)
+                    // ... and mark the next point as a split point
+                    nextPoint.properties._is_split_point = true
+                    // noinspection UnnecessaryContinueJS
+                    continue;
+                }
+            }
+            // We don't have to remove this point...
+        }*/
+
+        const splitInfo: SplitInfo[] = []
+        let nextId = -1
+
+        for (const p of allPoints) {
+            let index = p.properties._original_index
+            if (index === undefined) {
+                index = nextId;
+                nextId--;
+            }
+            const splitInfoElement = {
+                originalIndex: index,
+                lngLat: p.geometry.coordinates,
+                doSplit: p.properties._is_split_point
+            }
+            splitInfo.push(splitInfoElement)
+        }
+
+        return splitInfo
+    }
+
+
+}

Logic/Osm/Changes.ts

@@ -1,81 +1,225 @@
-import {OsmNode, OsmObject} from "./OsmObject";
+import {OsmNode, OsmObject, OsmRelation, OsmWay} from "./OsmObject";
 import State from "../../State";
-import {Utils} from "../../Utils";
 import {UIEventSource} from "../UIEventSource";
 import Constants from "../../Models/Constants";
-import FeatureSource from "../FeatureSource/FeatureSource";
-import {TagsFilter} from "../Tags/TagsFilter";
-import {Tag} from "../Tags/Tag";
-import {OsmConnection} from "./OsmConnection";
+import OsmChangeAction from "./Actions/OsmChangeAction";
+import {ChangeDescription} from "./Actions/ChangeDescription";
 import {LocalStorageSource} from "../Web/LocalStorageSource";
+import {Utils} from "../../Utils";
 
 /**
  * Handles all changes made to OSM.
  * Needs an authenticator via OsmConnection
  */
-export class Changes implements FeatureSource {
+export class Changes {
 
 
     private static _nextId = -1; // Newly assigned ID's are negative
     public readonly name = "Newly added features"
     /**
-     * The newly created points, as a FeatureSource
+     * All the newly created features as featureSource + all the modified features
      */
     public features = new UIEventSource<{ feature: any, freshness: Date }[]>([]);
-    /**
-     * All the pending changes
-     */
-    public readonly pending = LocalStorageSource.GetParsed<{ elementId: string, key: string, value: string }[]>("pending-changes", [])
-
-    /**
-     * All the pending new objects to upload
-     */
-    private readonly newObjects = LocalStorageSource.GetParsed<{ id: number, lat: number, lon: number }[]>("newObjects", [])
 
+    public readonly pendingChanges = new UIEventSource<ChangeDescription[]>([]) //  LocalStorageSource.GetParsed<ChangeDescription[]>("pending-changes", [])
     private readonly isUploading = new UIEventSource(false);
 
-    /**
-     * Adds a change to the pending changes
-     */
-    private static checkChange(kv: { k: string, v: string }): { k: string, v: string } {
-        const key = kv.k;
-        const value = kv.v;
-        if (key === undefined || key === null) {
-            console.log("Invalid key");
-            return undefined;
-        }
-        if (value === undefined || value === null) {
-            console.log("Invalid value for ", key);
-            return undefined;
-        }
-
-        if (key.startsWith(" ") || value.startsWith(" ") || value.endsWith(" ") || key.endsWith(" ")) {
-            console.warn("Tag starts with or ends with a space - trimming anyway")
-        }
-
-        return {k: key.trim(), v: value.trim()};
+    constructor() {
+        this.isUploading.addCallbackAndRun(u => {
+            if (u) {
+                console.trace("Uploading set!")
+            }
+        })
     }
 
+    public static createChangesetFor(csId: string,
+                                     allChanges: {
+                                         modifiedObjects?: OsmObject[],
+                                         newElements?: OsmObject[],
+                                         deletedElements?: OsmObject[]
+                                     }): string {
 
-    addTag(elementId: string, tagsFilter: TagsFilter,
-           tags?: UIEventSource<any>) {
-        const eventSource = tags ?? State.state?.allElements.getEventSourceById(elementId);
-        const elementTags = eventSource.data;
-        const changes = tagsFilter.asChange(elementTags).map(Changes.checkChange)
-        if (changes.length == 0) {
-            return;
+        const changedElements = allChanges.modifiedObjects ?? []
+        const newElements = allChanges.newElements ?? []
+        const deletedElements = allChanges.deletedElements ?? []
+
+        let changes = `<osmChange version='0.6' generator='Mapcomplete ${Constants.vNumber}'>`;
+        if (newElements.length > 0) {
+            changes +=
+                "\n<create>\n" +
+                newElements.map(e => e.ChangesetXML(csId)).join("\n") +
+                "</create>";
+        }
+        if (changedElements.length > 0) {
+            changes +=
+                "\n<modify>\n" +
+                changedElements.map(e => e.ChangesetXML(csId)).join("\n") +
+                "\n</modify>";
         }
 
+        if (deletedElements.length > 0) {
+            changes +=
+                "\n<deleted>\n" +
+                deletedElements.map(e => e.ChangesetXML(csId)).join("\n") +
+                "\n</deleted>"
+        }
+
+        changes += "</osmChange>";
+        return changes;
+    }
+
+    private static GetNeededIds(changes: ChangeDescription[]) {
+        return Utils.Dedup(changes.filter(c => c.id >= 0)
+            .map(c => c.type + "/" + c.id))
+    }
+
+    private static CreateChangesetObjects(changes: ChangeDescription[], downloadedOsmObjects: OsmObject[]): {
+        newObjects: OsmObject[],
+        modifiedObjects: OsmObject[]
+        deletedObjects: OsmObject[]
+
+    } {
+        const objects: Map<string, OsmObject> = new Map<string, OsmObject>()
+        const states: Map<string, "unchanged" | "created" | "modified" | "deleted"> = new Map();
+
+        for (const o of downloadedOsmObjects) {
+            objects.set(o.type + "/" + o.id, o)
+            states.set(o.type + "/" + o.id, "unchanged")
+        }
+
+        let changed = false;
         for (const change of changes) {
-            if (elementTags[change.k] !== change.v) {
-                elementTags[change.k] = change.v;
-                console.log("Applied ", change.k, "=", change.v)
-                // We use 'elementTags.id' here, as we might have retrieved with the id 'node/-1' as new point, but should use the rewritten id
-                this.pending.data.push({elementId: elementTags.id, key: change.k, value: change.v});
+            const id = change.type + "/" + change.id
+            if (!objects.has(id)) {
+                // This is a new object that should be created
+                states.set(id, "created")
+                let osmObj: OsmObject = undefined;
+                switch (change.type) {
+                    case "node":
+                        const n = new OsmNode(change.id)
+                        n.lat = change.changes["lat"]
+                        n.lon = change.changes["lon"]
+                        osmObj = n
+                        break;
+                    case "way":
+                        const w = new OsmWay(change.id)
+                        w.nodes = change.changes["nodes"]
+                        osmObj = w
+                        break;
+                    case "relation":
+                        const r = new OsmRelation(change.id)
+                        r.members = change.changes["members"]
+                        osmObj = r
+                        break;
+                }
+                if (osmObj === undefined) {
+                    throw "Hmm? This is a bug"
+                }
+                objects.set(id, osmObj)
+            }
+
+            const state = states.get(id)
+            if (change.doDelete) {
+                if (state === "created") {
+                    states.set(id, "unchanged")
+                } else {
+                    states.set(id, "deleted")
+                }
+            }
+
+            const obj = objects.get(id)
+            // Apply tag changes
+            for (const kv of change.tags ?? []) {
+                const k = kv.k
+                let v = kv.v
+
+                if (v === "") {
+                    v = undefined;
+                }
+
+                const oldV = obj.type[k]
+                if (oldV === v) {
+                    continue;
+                }
+
+                obj.tags[k] = v;
+                changed = true;
+
+
+            }
+
+            if (change.changes !== undefined) {
+                switch (change.type) {
+                    case "node":
+                        // @ts-ignore
+                        const nlat = change.changes.lat;
+                        // @ts-ignore
+                        const nlon = change.changes.lon;
+                        const n = <OsmNode>obj
+                        if (n.lat !== nlat || n.lon !== nlon) {
+                            n.lat = nlat;
+                            n.lon = nlon;
+                            changed = true;
+                        }
+                        break;
+                    case "way":
+                        const nnodes = change.changes["nodes"]
+                        const w = <OsmWay>obj
+                        if (!Utils.Identical(nnodes, w.nodes)) {
+                            w.nodes = nnodes
+                            changed = true;
+                        }
+                        break;
+                    case "relation":
+                        const nmembers: { type: "node" | "way" | "relation", ref: number, role: string }[] = change.changes["members"]
+                        const r = <OsmRelation>obj
+                        if (!Utils.Identical(nmembers, r.members, (a, b) => {
+                            return a.role === b.role && a.type === b.type && a.ref === b.ref
+                        })) {
+                            r.members = nmembers;
+                            changed = true;
+                        }
+                        break;
+
+                }
+               
+            }
+
+            if (changed && state === "unchanged") {
+                states.set(id, "modified")
             }
         }
-        this.pending.ping();
-        eventSource.ping();
+
+
+        const result = {
+            newObjects: [],
+            modifiedObjects: [],
+            deletedObjects: []
+
+        }
+        objects.forEach((v, id) => {
+
+            const state = states.get(id)
+            if (state === "created") {
+                result.newObjects.push(v)
+            }
+            if (state === "modified") {
+                result.modifiedObjects.push(v)
+            }
+            if (state === "deleted") {
+                result.deletedObjects.push(v)
+            }
+
+        })
+
+        return result
+    }
+
+    /**
+     * Returns a new ID and updates the value for the next ID
+     */
+    public getNewID() {
+        return Changes._nextId--;
     }
 
     /**
@@ -83,121 +227,16 @@ export class Changes implements FeatureSource {
      * Triggered by the 'PendingChangeUploader'-actor in Actors
      */
     public flushChanges(flushreason: string = undefined) {
-        if (this.pending.data.length === 0) {
+        if (this.pendingChanges.data.length === 0) {
+            console.log("No pending changes")
             return;
         }
         if (flushreason !== undefined) {
             console.log(flushreason)
         }
-        this.uploadAll();
-    }
-
-    /**
-     * Returns a new ID and updates the value for the next ID
-     */
-    public getNewID(){
-        return Changes._nextId--;
-    }
-
-    /**
-     * Create a new node element at the given lat/long.
-     * An internal OsmObject is created to upload later on, a geojson represention is returned.
-     * Note that the geojson version shares the tags (properties) by pointer, but has _no_ id in properties
-     */
-    public createElement(basicTags: Tag[], lat: number, lon: number) {
-        console.log("Creating a new element with ", basicTags)
-
-        const osmNode = new OsmNode(this.getNewID());
-        const properties = {id: osmNode.id};
-        const geojson = {
-            "type": "Feature",
-            "properties": properties,
-            "id": properties.id,
-            "geometry": {
-                "type": "Point",
-                "coordinates": [
-                    lon,
-                    lat
-                ]
-            }
-        }
-
-        // The basictags are COPIED, the id is included in the properties
-        // The tags are not yet written into the OsmObject, but this is applied onto a 
-        const changes = [];
-        for (const kv of basicTags) {
-            if (typeof kv.value !== "string") {
-                throw "Invalid value: don't use a regex in a preset"
-            }
-            properties[kv.key] = kv.value;
-            changes.push({elementId:properties.id, key: kv.key, value: kv.value})
-        }
-
-        console.log("New feature added and pinged")
-        this.features.data.push({feature: geojson, freshness: new Date()});
-        this.features.ping();
-
-        State.state.allElements.addOrGetElement(geojson).ping();
-
-        if (State.state.osmConnection.userDetails.data.backend !== OsmConnection.oauth_configs.osm.url) {
-            properties["_backend"] = State.state.osmConnection.userDetails.data.backend
-        }
-
-
-        this.newObjects.data.push({id: osmNode.id, lat: lat, lon: lon})
-        this.pending.data.push(...changes)
-        this.pending.ping();
-        this.newObjects.ping();
-        return geojson;
-    }
-
-
-    private uploadChangesWithLatestVersions(
-        knownElements: OsmObject[]) {
-        const knownById = new Map<string, OsmObject>();
-        knownElements.forEach(knownElement => {
-            knownById.set(knownElement.type + "/" + knownElement.id, knownElement)
-        })
-
-        const newElements: OsmNode [] = this.newObjects.data.map(spec => {
-            const newElement = new OsmNode(spec.id);
-            newElement.lat = spec.lat;
-            newElement.lon = spec.lon;
-            return newElement
-        })
-
-
-        // Here, inside the continuation, we know that all 'neededIds' are loaded in 'knownElements', which maps the ids onto the elements
-        // We apply the changes on them
-        for (const change of this.pending.data) {
-            if (parseInt(change.elementId.split("/")[1]) < 0) {
-                // This is a new element - we should apply this on one of the new elements
-                for (const newElement of newElements) {
-                    if (newElement.type + "/" + newElement.id === change.elementId) {
-                        newElement.addTag(change.key, change.value);
-                    }
-                }
-            } else {
-                knownById.get(change.elementId).addTag(change.key, change.value);
-            }
-        }
-
-        // Small sanity check for duplicate information
-        let changedElements = [];
-        for (const elementId in knownElements) {
-            const element = knownElements[elementId];
-            if (element.changed) {
-                changedElements.push(element);
-            }
-        }
-        if (changedElements.length == 0 && newElements.length == 0) {
-            console.log("No changes in any object - clearing");
-            this.pending.setData([])
-            this.newObjects.setData([])
-            return;
-        }
 
         if (this.isUploading.data) {
+            console.log("Is uploading... Abort")
             return;
         }
         this.isUploading.setData(true)
@@ -205,75 +244,45 @@ export class Changes implements FeatureSource {
         console.log("Beginning upload...");
         // At last, we build the changeset and upload
         const self = this;
-        State.state.osmConnection.UploadChangeset(
-            State.state.layoutToUse.data,
-            State.state.allElements,
-            (csId) =>   Changes.createChangesetFor(csId,changedElements, newElements ),
-            () => {
-                // When done
-                console.log("Upload successfull!")
-                self.newObjects.setData([])
-                self.pending.setData([]);
-                self.isUploading.setData(false)
-            },
-            () => self.isUploading.setData(false) // Failed - mark to try again
-            );
-
-     
-    };
-
-
-    public static createChangesetFor(csId: string, changedElements: OsmObject[], newElements: OsmObject[]): string {
-
-        let modifications = "";
-        for (const element of changedElements) {
-            modifications += element.ChangesetXML(csId) + "\n";
-        }
-
-
-        let creations = "";
-        for (const newElement of newElements) {
-            creations += newElement.ChangesetXML(csId);
-        }
-
-
-        let changes = `<osmChange version='0.6' generator='Mapcomplete ${Constants.vNumber}'>`;
-
-        if (creations.length > 0) {
-            changes +=
-                "\n<create>\n" +
-                creations +
-                "</create>";
-        }
-        if (modifications.length > 0) {
-            changes +=
-                "\n<modify>\n" +
-                modifications +
-                "\n</modify>";
-        }
-        
-        changes += "</osmChange>";
-        return changes;
-    }
-
-    private uploadAll() {
-        const self = this;
-
-        const pending = this.pending.data;
-        let neededIds: string[] = [];
-        for (const change of pending) {
-            const id = change.elementId;
-            if (parseFloat(id.split("/")[1]) < 0) {
-                // New element - we don't have to download this
-            } else {
-                neededIds.push(id);
+        const pending = self.pendingChanges.data;
+        const neededIds =  Changes.GetNeededIds(pending)
+        console.log("Needed ids", neededIds)
+        OsmObject.DownloadAll(neededIds, true).addCallbackAndRunD(osmObjects => {
+            console.log("Got the fresh objects!", osmObjects, "pending: ", pending)
+            const changes = Changes.CreateChangesetObjects(pending, osmObjects)
+            console.log("Changes", changes)
+            if (changes.newObjects.length + changes.deletedObjects.length + changes.modifiedObjects.length === 0) {
+                console.log("No changes to be made")
+                this.pendingChanges.setData([])
+                this.isUploading.setData(false)
+                return;
             }
-        }
 
-        neededIds = Utils.Dedup(neededIds);
-        OsmObject.DownloadAll(neededIds).addCallbackAndRunD(knownElements => {
-            self.uploadChangesWithLatestVersions(knownElements)
-        })
+
+            State.state.osmConnection.UploadChangeset(
+                State.state.layoutToUse.data,
+                State.state.allElements,
+                (csId) => {
+                    return Changes.createChangesetFor(csId, changes);
+                },
+                () => {
+                    // When done
+                    console.log("Upload successfull!")
+                    self.pendingChanges.setData([]);
+                    self.isUploading.setData(false)
+                },
+                () => self.isUploading.setData(false) // Failed - mark to try again
+            )
+
+        });
+
+
     }
 
+    public applyAction(action: OsmChangeAction) {
+        const changes = action.Perform(this)
+        console.log("Received changes:", changes)
+        this.pendingChanges.data.push(...changes);
+        this.pendingChanges.ping();
+    }
 }

Logic/Osm/CreateNewNodeAction.ts

@@ -1,3 +0,0 @@
-export default class CreateNewNodeAction {
-    
-}

Logic/Osm/OsmObject.ts

@@ -125,7 +125,7 @@ export abstract class OsmObject {
         }
         const splitted = id.split("/");
         const type = splitted[0];
-        const idN = splitted[1];
+        const idN = Number(splitted[1]);
         const src = new UIEventSource<OsmObject[]>([]);
         OsmObject.historyCache.set(id, src);
         Utils.downloadJson(`${OsmObject.backendURL}api/0.6/${type}/${idN}/history`).then(data => {
@@ -314,20 +314,6 @@ export abstract class OsmObject {
         return this;
     }
 
-    public addTag(k: string, v: string): void {
-        if (k in this.tags) {
-            const oldV = this.tags[k];
-            if (oldV == v) {
-                return;
-            }
-            console.log("Overwriting ", oldV, " with ", v, " for key ", k)
-        }
-        this.tags[k] = v;
-        if (v === undefined || v === "") {
-            delete this.tags[k];
-        }
-        this.changed = true;
-    }
 
     abstract ChangesetXML(changesetId: string): string;
 
@@ -481,7 +467,11 @@ export class OsmWay extends OsmObject {
 
 export class OsmRelation extends OsmObject {
 
-    public members;
+    public members: {
+        type: "node" | "way" | "relation",
+        ref: number,
+        role: string
+    }[];
 
     constructor(id: number) {
         super("relation", id);

Logic/Osm/RelationSplitlHandler.ts

@@ -1,11 +0,0 @@
-/**
- * The logic to handle relations after a way within 
- */
-export default class RelationSplitlHandler {
-
-    constructor() {
-        
-    }
-
-
-}

Logic/Osm/SplitAction.ts

@@ -1,222 +0,0 @@
-import {OsmNode, OsmObject, OsmRelation, OsmWay} from "./OsmObject";
-import {GeoOperations} from "../GeoOperations";
-import State from "../../State";
-import {UIEventSource} from "../UIEventSource";
-import {Changes} from "./Changes";
-
-interface SplitInfo {
-    originalIndex?: number, // or negative for new elements
-    lngLat: [number, number],
-    doSplit: boolean
-}
-
-export default class SplitAction {
-    private readonly roadObject: any;
-
-    /***
-     *
-     * @param roadObject: the geojson of the road object. Properties.id must be the corresponding OSM-id
-     */
-    constructor(roadObject: any) {
-        this.roadObject = roadObject;
-    }
-
-    private static SegmentSplitInfo(splitInfo: SplitInfo[]): SplitInfo[][] {
-        const wayParts = []
-        let currentPart = []
-        for (const splitInfoElement of splitInfo) {
-            currentPart.push(splitInfoElement)
-
-            if (splitInfoElement.doSplit) {
-                // We have to do a split!
-                // We add the current index to the currentParts, flush it and add it again
-                wayParts.push(currentPart)
-                currentPart = [splitInfoElement]
-            }
-        }
-        wayParts.push(currentPart)
-        return wayParts
-    }
-
-    public DoSplit(splitPoints: any[]) {
-        // We mark the new split points with a new id
-        for (const splitPoint of splitPoints) {
-            splitPoint.properties["_is_split_point"] = true
-        }
-
-
-        const self = this;
-        const id = this.roadObject.properties.id
-        const osmWay = <UIEventSource<OsmWay>>OsmObject.DownloadObject(id)
-        const partOf = OsmObject.DownloadReferencingRelations(id)
-        osmWay.map(originalElement => {
-
-            if(originalElement === undefined || partOf === undefined){
-                return;
-            }
-            
-            const changes = State.state?.changes ?? new Changes();
-            // First, calculate splitpoints and remove points close to one another
-            const splitInfo = self.CalculateSplitCoordinates(splitPoints)
-            // Now we have a list with e.g. 
-            // [ { originalIndex: 0}, {originalIndex: 1, doSplit: true}, {originalIndex: 2}, {originalIndex: undefined, doSplit: true}, {originalIndex: 3}]
-
-            // Lets change 'originalIndex' to the actual node id first:
-            for (const element of splitInfo) {
-                if (element.originalIndex >= 0) {
-                    element.originalIndex = originalElement.nodes[element.originalIndex]
-                } else {
-                    element.originalIndex = changes.getNewID();
-                }
-            }
-
-            // Next up is creating actual parts from this
-            const wayParts = SplitAction.SegmentSplitInfo(splitInfo);
-
-            // Allright! At this point, we have our new ways!
-            // Which one is the longest of them (and can keep the id)?
-
-            let longest = undefined;
-            for (const wayPart of wayParts) {
-                if (longest === undefined) {
-                    longest = wayPart;
-                    continue
-                }
-                if (wayPart.length > longest.length) {
-                    longest = wayPart
-                }
-            }
-
-            const newOsmObjects: OsmObject[] = []
-            const modifiedObjects: OsmObject[] = []
-            // Let's create the new points as needed
-            for (const element of splitInfo) {
-                if (element.originalIndex >= 0) {
-                    continue;
-                }
-                const node = new OsmNode(element.originalIndex)
-                node.lon = element.lngLat[0]
-                node.lat = element.lngLat[1]
-                newOsmObjects.push(node)
-            }
-
-            const newWayIds: number[] = []
-            // Lets create OsmWays based on them
-            for (const wayPart of wayParts) {
-
-                let isOriginal = wayPart === longest
-                if(isOriginal){
-                    // We change the actual element!
-                    originalElement.nodes = wayPart.map(p => p.originalIndex);
-                    originalElement.changed = true;
-                    modifiedObjects.push(originalElement)
-                }else{
-                    let id = changes.getNewID();
-                    const way = new OsmWay(id)
-                    way.tags = originalElement.tags;
-                    way.nodes = wayPart.map(p => p.originalIndex);
-                    way.changed = true;
-                    newOsmObjects.push(way)
-                        newWayIds.push(way.id)
-                }
-             
-            }
-            
-            // At last, we still have to check that we aren't part of a relation...
-            // At least, the order of the ways is identical, so we can keep the same roles
-
-            modifiedObjects.push(...SplitAction.UpdateRelations(partOf.data, newWayIds, originalElement))
-            // And we have our objects!
-            // Time to upload
-
-            console.log(Changes.createChangesetFor("123", modifiedObjects, newOsmObjects))
-        }, [partOf])
-    }
-
-    private static UpdateRelations(data: OsmRelation[], newWayIds: number[], originalElement: OsmWay):OsmRelation[]{
-        // TODO
-        return []
-    }
-    
-    /**
-     * Calculates the actual points to split
-     * If another point is closer then ~5m, we reuse that point
-     */
-    private CalculateSplitCoordinates(
-        splitPoints: any[],
-        toleranceInM = 5): SplitInfo[] {
-
-        const allPoints = [...splitPoints];
-        // We have a bunch of coordinates here: [ [lat, lon], [lat, lon], ...] ...
-        const originalPoints: [number, number][] = this.roadObject.geometry.coordinates
-        // We project them onto the line (which should yield pretty much the same point
-        for (let i = 0; i < originalPoints.length; i++) {
-            let originalPoint = originalPoints[i];
-            let projected = GeoOperations.nearestPoint(this.roadObject, originalPoint)
-            projected.properties["_is_split_point"] = false
-            projected.properties["_original_index"] = i
-            allPoints.push(projected)
-        }
-        // At this point, we have a list of both the split point and the old points, with some properties to discriminate between them
-        // We sort this list so that the new points are at the same location
-        allPoints.sort((a, b) => a.properties.location - b.properties.location)
-
-        // When this is done, we check that no now point is too close to an already existing point and no very small segments get created
-
-        for (let i = allPoints.length - 1; i > 0; i--) {
-
-            const point = allPoints[i];
-            if (point.properties._original_index !== undefined) {
-                // This point is already in OSM - we have to keep it!
-                continue;
-            }
-
-            if (i != allPoints.length - 1) {
-                const prevPoint = allPoints[i + 1]
-                const diff = Math.abs(point.properties.location - prevPoint.properties.location) * 1000
-                if (diff <= toleranceInM) {
-                    // To close to the previous point! We delete this point...
-                    allPoints.splice(i, 1)
-                    // ... and mark the previous point as a split point
-                    prevPoint.properties._is_split_point = true
-                    continue;
-                }
-            }
-
-            if (i > 0) {
-                const nextPoint = allPoints[i - 1]
-                const diff = Math.abs(point.properties.location - nextPoint.properties.location) * 1000
-                if (diff <= toleranceInM) {
-                    // To close to the next point! We delete this point...
-                    allPoints.splice(i, 1)
-                    // ... and mark the next point as a split point
-                    nextPoint.properties._is_split_point = true
-                    // noinspection UnnecessaryContinueJS
-                    continue;
-                }
-            }
-            // We don't have to remove this point...
-        }
-
-        const splitInfo: SplitInfo[] = []
-        let nextId = -1
-
-        for (const p of allPoints) {
-            let index = p.properties._original_index
-            if (index === undefined) {
-                index = nextId;
-                nextId--;
-            }
-            const splitInfoElement = {
-                originalIndex: index,
-                lngLat: p.geometry.coordinates,
-                doSplit: p.properties._is_split_point
-            }
-            splitInfo.push(splitInfoElement)
-        }
-
-        return splitInfo
-    }
-
-
-}

Logic/UIEventSource.ts

@@ -2,21 +2,27 @@ import {Utils} from "../Utils";
 
 export class UIEventSource<T> {
 
+    private static allSources: UIEventSource<any>[] = UIEventSource.PrepPerf();
     public data: T;
+    public trace: boolean;
     private readonly tag: string;
     private _callbacks = [];
-    
-    private static allSources : UIEventSource<any>[] = UIEventSource.PrepPerf();
-    
-    static PrepPerf() : UIEventSource<any>[]{
-        if(Utils.runningFromConsole){
+
+    constructor(data: T, tag: string = "") {
+        this.tag = tag;
+        this.data = data;
+        UIEventSource.allSources.push(this);
+    }
+
+    static PrepPerf(): UIEventSource<any>[] {
+        if (Utils.runningFromConsole) {
             return [];
         }
         // @ts-ignore
         window.mapcomplete_performance = () => {
             console.log(UIEventSource.allSources.length, "uieventsources created");
             const copy = [...UIEventSource.allSources];
-            copy.sort((a,b) => b._callbacks.length - a._callbacks.length);
+            copy.sort((a, b) => b._callbacks.length - a._callbacks.length);
             console.log("Topten is:")
             for (let i = 0; i < 10; i++) {
                 console.log(copy[i].tag, copy[i]);
@@ -25,13 +31,7 @@ export class UIEventSource<T> {
         }
         return [];
     }
-
-    constructor(data: T, tag: string = "") {
-        this.tag = tag;
-        this.data = data;
-        UIEventSource.allSources.push(this);
-    }
-
+    
     public static flatten<X>(source: UIEventSource<UIEventSource<X>>, possibleSources: UIEventSource<any>[]): UIEventSource<X> {
         const sink = new UIEventSource<X>(source.data?.data);
 
@@ -68,6 +68,9 @@ export class UIEventSource<T> {
             // This ^^^ actually works!
             throw "Don't add console.log directly as a callback - you'll won't be able to find it afterwards. Wrap it in a lambda instead."
         }
+        if (this.trace) {
+            console.trace("Added a callback")
+        }
         this._callbacks.push(callback);
         return this;
     }
@@ -101,12 +104,12 @@ export class UIEventSource<T> {
      */
     public map<J>(f: ((t: T) => J),
                   extraSources: UIEventSource<any>[] = [],
-                  g: ((j:J, t:T) => T) = undefined): UIEventSource<J> {
+                  g: ((j: J, t: T) => T) = undefined): UIEventSource<J> {
         const self = this;
 
         const newSource = new UIEventSource<J>(
             f(this.data),
-            "map("+this.tag+")"
+            "map(" + this.tag + ")"
         );
 
         const update = function () {
@@ -159,9 +162,9 @@ export class UIEventSource<T> {
         return newSource;
     }
 
-    addCallbackAndRunD(callback: (data :T ) => void) {
+    addCallbackAndRunD(callback: (data: T) => void) {
         this.addCallbackAndRun(data => {
-            if(data !== undefined && data !== null){
+            if (data !== undefined && data !== null) {
                 callback(data)
             }
         })