Refactor OsmObject to use eventsources, add first version of the delete button

Logic/Osm/ChangesetHandler.ts

@@ -7,6 +7,7 @@ import State from "../../State";
 import Locale from "../../UI/i18n/Locale";
 import LayoutConfig from "../../Customizations/JSON/LayoutConfig";
 import Constants from "../../Models/Constants";
+import {OsmObject} from "./OsmObject";
 
 export class ChangesetHandler {
 
@@ -47,11 +48,20 @@ export class ChangesetHandler {
         }
     }
 
+    /**
+     * The full logic to upload a change to one or more elements.
+     *
+     * This method will attempt to reuse an existing, open changeset for this theme (or open one if none available).
+     * Then, it will upload a changes-xml within this changeset (and leave the changeset open)
+     * When upload is successfull, eventual id-rewriting will be handled (aka: don't worry about that)
+     *
+     * If 'dryrun' is specified, the changeset XML will be printed to console instead of being uploaded
+     *
+     */
     public UploadChangeset(
         layout: LayoutConfig,
         allElements: ElementStorage,
-        generateChangeXML: (csid: string) => string,
-        continuation: () => void) {
+        generateChangeXML: (csid: string) => string) {
 
         if (this.userDetails.data.csCount == 0) {
             // The user became a contributor!
@@ -62,7 +72,6 @@ export class ChangesetHandler {
         if (this._dryRun) {
             const changesetXML = generateChangeXML("123456");
             console.log(changesetXML);
-            continuation();
             return;
         }
 
@@ -97,7 +106,7 @@ export class ChangesetHandler {
                     // Mark the CS as closed...
                     this.currentChangeset.setData("");
                     // ... and try again. As the cs is closed, no recursive loop can exist  
-                    self.UploadChangeset(layout, allElements, generateChangeXML, continuation);
+                    self.UploadChangeset(layout, allElements, generateChangeXML);
 
                 }
             )
@@ -105,7 +114,60 @@ export class ChangesetHandler {
         }
     }
 
-    public CloseChangeset(changesetId: string = undefined, continuation: (() => void) = () => {
+
+    /**
+     * Deletes the element with the given ID from the OSM database.
+     * DOES NOT PERFORM ANY SAFETY CHECKS!
+     *
+     * For the deletion of an element, a new, seperate changeset is created with a slightly changed comment and some extra flags set.
+     * The CS will be closed afterwards.
+     *
+     * If dryrun is specified, will not actually delete the point but print the CS-XML to console instead
+     *
+     */
+    public DeleteElement(object: OsmObject,
+                         layout: LayoutConfig,
+                         reason: string,
+                         allElements: ElementStorage,
+                         continuation: () => void) {
+
+        function generateChangeXML(csId: string) {
+            let [lat, lon] = object.centerpoint();
+
+            let changes = `<osmChange version='0.6' generator='Mapcomplete ${Constants.vNumber}'>`;
+            changes +=
+                `<delete><${object.type} id="${object.id}" version="${object.version}" changeset="${csId}" lat="${lat}" lon="${lon}" /></delete>`;
+            changes += "</osmChange>";
+
+            return changes;
+
+        }
+
+
+        if (this._dryRun) {
+            const changesetXML = generateChangeXML("123456");
+            console.log(changesetXML);
+            return;
+        }
+
+        const self = this;
+        this.OpenChangeset(layout, (csId: string) => {
+            
+            // The cs is open - let us actually upload!
+            const changes = generateChangeXML(csId)
+            
+            self.AddChange(csId, changes, allElements, (csId) => {
+                console.log("Successfully deleted ", object.id)
+                self.CloseChangeset(csId, continuation)
+            }, (csId) => {
+                alert("Deletion failed... Should not happend")
+                // FAILED
+                self.CloseChangeset(csId, continuation)
+            })
+        }, true, reason)
+    }
+
+    private CloseChangeset(changesetId: string = undefined, continuation: (() => void) = () => {
     }) {
         if (changesetId === undefined) {
             changesetId = this.currentChangeset.data;
@@ -133,15 +195,25 @@ export class ChangesetHandler {
 
     private OpenChangeset(
         layout: LayoutConfig,
-        continuation: (changesetId: string) => void) {
+        continuation: (changesetId: string) => void,
+        isDeletionCS: boolean = false,
+        deletionReason: string = undefined) {
 
         const commentExtra = layout.changesetmessage !== undefined ? " - " + layout.changesetmessage : "";
+        let comment = `Adding data with #MapComplete for theme #${layout.id}${commentExtra}`
+        if (isDeletionCS) {
+            comment = `Deleting a point with #MapComplete for theme #${layout.id}${commentExtra}`
+            if(deletionReason){
+                comment += ": "+deletionReason;
+            }
+        }
 
         let path = window.location.pathname;
         path = path.substr(1, path.lastIndexOf("/"));
         const metadata = [
             ["created_by", `MapComplete ${Constants.vNumber}`],
-            ["comment", `Adding data with #MapComplete for theme #${layout.id}${commentExtra}`],
+            ["comment", comment],
+            ["deletion", isDeletionCS ? "yes" : undefined],
             ["theme", layout.id],
             ["language", Locale.language.data],
             ["host", window.location.host],
@@ -172,11 +244,21 @@ export class ChangesetHandler {
         });
     }
 
+    /**
+     * Upload a changesetXML
+     * @param changesetId
+     * @param changesetXML
+     * @param allElements
+     * @param continuation
+     * @param onFail
+     * @constructor
+     * @private
+     */
     private AddChange(changesetId: string,
                       changesetXML: string,
                       allElements: ElementStorage,
                       continuation: ((changesetId: string, idMapping: any) => void),
-                      onFail: ((changesetId: string) => void) = undefined) {
+                      onFail: ((changesetId: string, reason: string) => void) = undefined) {
         this.auth.xhr({
             method: 'POST',
             options: {header: {'Content-Type': 'text/xml'}},
@@ -186,7 +268,7 @@ export class ChangesetHandler {
             if (response == null) {
                 console.log("err", err);
                 if (onFail) {
-                    onFail(changesetId);
+                    onFail(changesetId, err);
                 }
                 return;
             }