From 300d1eac60554574f6dd175076a77c7bcfe4d3a6 Mon Sep 17 00:00:00 2001
From: Stuart Breckenridge <stuart.breckenridge@icloud.com>
Date: Sat, 11 Jul 2020 22:24:49 +0800
Subject: [PATCH] Widget.md

---
 Technotes/Widget.md | 43 ++++++++++++++++++-------------------------
 1 file changed, 18 insertions(+), 25 deletions(-)

diff --git a/Technotes/Widget.md b/Technotes/Widget.md
index 5d99ff6d4..c14ae3255 100644
--- a/Technotes/Widget.md
+++ b/Technotes/Widget.md
@@ -4,39 +4,32 @@
 
 The NetNewsWire iOS widget supports the `systemSmall` and `systemMedium` styles. 
 
-The `systemSmall` style displays the current Today and Unread counts; `systemMedium` displays the latest two articles.
+For the purpose of this PoC: the `systemSmall` style displays the current Today and Unread counts; `systemMedium` displays the latest two articles. 
 
 ## Passing Data from the App to the Widget
 
-Data is made available to the widget by encoding JSON data and saving it to a file in a directory available to app extensions. 
+Data is made available to the widget by encoding smart feed and article data as JSON, and saving it to a file in a directory available to app extensions. 
 
+Three `struct`s are responsible for this:
 
-```
-struct WidgetData: Codable {
-
-    let currentUnreadCount: Int 
-    let currentTodayCount: Int
-    let latestArticles: [LatestArticle]
-    let lastUpdateTime: Date
-
-}
-
-struct LatestArticle: Codable {
-
-    let feedTitle: String
-    let articleTitle: String?
-    let articleSummary: String?
-    let feedIcon: Data? // Base64 encoded image data
-    let pubDate: String
-
-}
-```
+- `WidgetDataEncoder` (which is available to the app);
+- `WidgetDataDecoder` (which is available to the widget); and,
+- `WidgetData` (which is available to both app and widget, and includes the data neccessary for the widget to function)
 
 ## When is JSON Data Saved?
 
-1. When the app enters the background
-2. After a background refresh
+1. When the app enters the background (monitored via the `scenePhase` changing (tested)); or,
+2. After a background refresh (untested at the time of writing)
+
+Encoding tasks are fenced in 
+```
+UIApplication.shared.beginBackgroundTask
+_{ encoding task }_
+UIApplication.shared.endBackgroundTask
+```
+in order to ensure that the file can be written with sufficient time to spare. 
+
+After JSON data is saved, Widget timelines are reloaded. 
 
-After JSON data is saved, Widget timelines are reloaded.