add control for feed sync interval

fixes #25

index.html

@@ -142,6 +142,9 @@
 		.bar > .feed input {
 			width: 100%;
 		}
+		.bar > .feed > .interval {
+			width: 3em;
+		}
 		@keyframes spinning {
 			0% {
 				transform: rotate(0deg);

stores/feed.js

@@ -14,6 +14,7 @@ const CONTENT_TYPES = [
 const feedStore = (state, bus) => {
 	state.feedUrl = null
 	state.feedSyncStopped = false
+	state.feedSyncInterval = 30 // 30s
 	state.feedSyncing = false
 	state.feedError = null
 	state.feedRawData = null
@@ -58,7 +59,7 @@ const feedStore = (state, bus) => {
 	}
 	const resetSync = debounce(() => {
 		sync = syncViaPeriodicFetch(state.feedUrl, {
-			interval: 30 * 1000, // 30s
+			interval: state.feedSyncInterval * 1000,
 		})
 		sync.on('fetch', () => setSyncing(true))
 		sync.on('fetch-done', () => setSyncing(false))
@@ -109,6 +110,23 @@ const feedStore = (state, bus) => {
 		if (sync) sync.start()
 		bus.emit(bus.STATE_CHANGE)
 	})
+
+	bus.on('feed:set-sync-interval', (newInterval) => {
+		newInterval = Math.max(newInterval, 1)
+		if (newInterval === state.feedSyncInterval) return; // nothing changed, abort
+
+		// todo: change `sync`'s interval directly
+		// clean up
+		if (sync) {
+			sync.stop()
+			sync = null
+		}
+
+		state.feedSyncInterval = newInterval
+		if (state.feedUrl !== null) resetSync()
+
+		bus.emit(bus.STATE_CHANGE)
+	})
 }
 
 export default feedStore

stores/url.js

@@ -7,6 +7,7 @@ const qsParse = memoize(_qsParse)
 
 const decodeString = str => str
 const decodeBoolean = str => str === 'true'
+const decodeInteger = str => parseInt(str)
 const PERSISTED_STATE_FIELDS = {
 	// stores/feed
 	'feedUrl': {
@@ -19,6 +20,12 @@ const PERSISTED_STATE_FIELDS = {
 			bus.emit(`feed:${stopped ? 'stop' : 'start'}-sync`)
 		},
 	},
+	'feedSyncInterval': {
+		decode: decodeInteger,
+		apply: (interval, bus) => {
+			bus.emit('feed:set-sync-interval', interval)
+		},
+	},
 	// stores/view
 	'view': {
 		decode: decodeString,

views/bar.js

@@ -34,9 +34,21 @@ const barView = ({state, emit}) => {
 		if (state.feedSyncStopped) emit('feed:start-sync')
 		else emit('feed:stop-sync')
 	}
+	const handleSyncIntervalChange = (ev) => {
+		const val = parseInt(ev.target.value)
+		emit('feed:set-sync-interval', val)
+	}
 	const feed = (
 		<div class="feed">
 			<input onInput={handleFeedUrlInput} value={state.feedUrl} />
+			<input
+				class="interval"
+				type="number"
+				min="1"
+				step="10"
+				onChange={handleSyncIntervalChange}
+				value={state.feedSyncInterval}
+			/>
 			<button
 				class={state.feedSyncing ? 'sync syncing' : 'sync'}
 				onClick={handleSyncClick}