From 35b83b79762a00ed3b6809be951fe282be048f25 Mon Sep 17 00:00:00 2001
From: Bruno Windels <brunow@matrix.org>
Date: Fri, 9 Oct 2020 16:59:34 +0200
Subject: [PATCH] make SessionLoadViewModel transfer ownership of container
 with callback

also, deleting the session when navigating away is now done by
LoginViewModel
---
 src/domain/LoginViewModel.js       | 42 +++++++++++++++--------------
 src/domain/SessionLoadViewModel.js | 43 ++++++++++++++----------------
 2 files changed, 42 insertions(+), 43 deletions(-)

diff --git a/src/domain/LoginViewModel.js b/src/domain/LoginViewModel.js
index ed6ed67a..11ba3d73 100644
--- a/src/domain/LoginViewModel.js
+++ b/src/domain/LoginViewModel.js
@@ -20,10 +20,11 @@ import {SessionLoadViewModel} from "./SessionLoadViewModel.js";
 export class LoginViewModel extends ViewModel {
     constructor(options) {
         super(options);
-        const {sessionCallback, defaultHomeServer, createSessionContainer} = options;
+        const {ready, defaultHomeServer, createSessionContainer} = options;
         this._createSessionContainer = createSessionContainer;
-        this._sessionCallback = sessionCallback;
+        this._ready = ready;
         this._defaultHomeServer = defaultHomeServer;
+        this._sessionContainer = null;
         this._loadViewModel = null;
         this._loadViewModelSubscription = null;
     }
@@ -45,25 +46,19 @@ export class LoginViewModel extends ViewModel {
         if (this._loadViewModel) {
             this._loadViewModel.cancel();
         }
-        this._loadViewModel = new SessionLoadViewModel({
+        this._loadViewModel = this.track(new SessionLoadViewModel({
             createAndStartSessionContainer: () => {
-                const sessionContainer = this._createSessionContainer();
-                sessionContainer.startWithLogin(homeserver, username, password);
-                return sessionContainer;
+                this._sessionContainer = this._createSessionContainer();
+                this._sessionContainer.startWithLogin(homeserver, username, password);
+                return this._sessionContainer;
             },
-            sessionCallback: sessionContainer => {
-                if (sessionContainer) {
-                    // make parent view model move away
-                    this._sessionCallback(sessionContainer);
-                } else {
-                    // show list of session again
-                    this._loadViewModel = null;
-                    this.emitChange("loadViewModel");
-                }
+            ready: sessionContainer => {
+                // make sure we don't delete the session in dispose when navigating away
+                this._sessionContainer = null;
+                this._ready(sessionContainer);
             },
-            deleteSessionOnCancel: true,
             homeserver,
-        });
+        }));
         this._loadViewModel.start();
         this.emitChange("loadViewModel");
         this._loadViewModelSubscription = this.track(this._loadViewModel.disposableOn("change", () => {
@@ -74,9 +69,16 @@ export class LoginViewModel extends ViewModel {
         }));
     }
 
-    cancel() {
-        if (!this.isBusy) {
-            this._sessionCallback();
+    get cancelUrl() {
+        return this.urlRouter.urlForSegment("session");
+    }
+
+    dispose() {
+        super.dispose();
+        if (this._sessionContainer) {
+            // if we move away before we're done with initial sync
+            // delete the session
+            this._sessionContainer.deleteSession();
         }
     }
 }
diff --git a/src/domain/SessionLoadViewModel.js b/src/domain/SessionLoadViewModel.js
index e9454a24..d8736077 100644
--- a/src/domain/SessionLoadViewModel.js
+++ b/src/domain/SessionLoadViewModel.js
@@ -21,9 +21,9 @@ import {ViewModel} from "./ViewModel.js";
 export class SessionLoadViewModel extends ViewModel {
     constructor(options) {
         super(options);
-        const {createAndStartSessionContainer, sessionCallback, homeserver, deleteSessionOnCancel} = options;
+        const {createAndStartSessionContainer, ready, homeserver, deleteSessionOnCancel} = options;
         this._createAndStartSessionContainer = createAndStartSessionContainer;
-        this._sessionCallback = sessionCallback;
+        this._ready = ready;
         this._homeserver = homeserver;
         this._deleteSessionOnCancel = deleteSessionOnCancel;
         this._loading = false;
@@ -60,11 +60,17 @@ export class SessionLoadViewModel extends ViewModel {
 
             // did it finish or get stuck at LoginFailed or Error?
             const loadStatus = this._sessionContainer.loadStatus.get();
+            const loadError = this._sessionContainer.loadError;
             if (loadStatus === LoadStatus.FirstSync || loadStatus === LoadStatus.Ready) {
-                this._sessionCallback(this._sessionContainer);
+                const sessionContainer = this._sessionContainer;
+                // session container is ready,
+                // don't dispose it anymore when 
+                // we get disposed
+                this._sessionContainer = null;
+                this._ready(sessionContainer);
             }
-            if (this._sessionContainer.loadError) {
-                console.error("session load error", this._sessionContainer.loadError);
+            if (loadError) {
+                console.error("session load error", loadError);
             }
         } catch (err) {
             this._error = err;
@@ -77,24 +83,15 @@ export class SessionLoadViewModel extends ViewModel {
     }
 
 
-    async cancel() {
-        try {
-            if (this._sessionContainer) {
-                this._sessionContainer.dispose();
-                if (this._deleteSessionOnCancel) {
-                    await this._sessionContainer.deleteSession();
-                }
-                this._sessionContainer = null;
-            }
-            if (this._waitHandle) {
-                // rejects with AbortError
-                this._waitHandle.dispose();
-                this._waitHandle = null;
-            }
-            this._sessionCallback();
-        } catch (err) {
-            this._error = err;
-            this.emitChange();
+    dispose() {
+        if (this._sessionContainer) {
+            this._sessionContainer.dispose();
+            this._sessionContainer = null;
+        }
+        if (this._waitHandle) {
+            // rejects with AbortError
+            this._waitHandle.dispose();
+            this._waitHandle = null;
         }
     }