fds

files/assets/js/new_comments_count.js

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+// only allows the script to execute once
+if (typeof showNewCommentCounts === 'undefined') {
+
+	// localstorage comment counts format: {"<postId>": {c: <totalComments>, t: <timestampUpdated>}}
+	const COMMENT_COUNTS_ID = "comment-counts"
+
+	/**
+		* Display the number of new comments present since the last time the post was opened
+		*/
+	function showNewCommentCounts(postId, newTotal) {
+		const comments = JSON.parse(localStorage.getItem(COMMENT_COUNTS_ID)) || {}
+
+		const lastCount = comments[postId]
+		if (lastCount) {
+			const newComments = newTotal - lastCount.c
+			if (newComments > 0) {
+				document.querySelectorAll(`#post-${postId} .new-comments`).forEach(elem => {
+					elem.textContent = ` (+${newComments})`
+					elem.classList.remove("d-none")
+				})
+			}
+		}
+	}
+
+	function incrementCommentCount(postId) {
+		saveCommentsCount(postId)
+	}
+
+	/**
+		* Saves the comment count to the localStorage
+		*
+		* @param postId The id of the post associated with the comments
+		* @param lastTotalComs The new amount, If null it will just increment the previous amount
+		*/
+	function saveCommentsCount(postId, lastTotalComs = null) {
+		const comments = JSON.parse(localStorage.getItem(COMMENT_COUNTS_ID)) || {}
+
+		const newTotal = lastTotalComs || ((comments[postId] || { c: 0 }).c + 1)
+
+		comments[postId] = { c: newTotal, t: Date.now() }
+
+		window.localStorage.setItem(COMMENT_COUNTS_ID, JSON.stringify(comments))
+	}
+
+
+	/**
+		* Cleans the expired entries (5 days). It runs every hour.
+		*/
+	function cleanCommentsCache() {
+		const LAST_CACHE_CLEAN_ID = "last-cache-clean"
+		const EXPIRE_INTERVAL_MILLIS = 5 * 24 * 60 * 60 * 1000
+		const CACHE_CLEAN_INTERVAL = 60 * 60 * 1000 // 1 hour
+
+		function cleanCache() {
+			const lastCacheClean = JSON.parse(localStorage.getItem(LAST_CACHE_CLEAN_ID)) || Date.now()
+			const now = Date.now()
+
+			if (now - lastCacheClean > CACHE_CLEAN_INTERVAL) {
+				const comments = JSON.parse(localStorage.getItem(COMMENT_COUNTS_ID)) || {}
+
+				for (let [key, value] of Object.entries(comments)) {
+					if (now - value.t > EXPIRE_INTERVAL_MILLIS) {
+						delete comments[key]
+					}
+				}
+				window.localStorage.setItem(COMMENT_COUNTS_ID, JSON.stringify(comments))
+			}
+			window.localStorage.setItem(LAST_CACHE_CLEAN_ID, JSON.stringify(now))
+		}
+
+		// So it does not slow the load of the main page with the clean up
+		setTimeout(cleanCache, 500)
+	}
+
+	cleanCommentsCache()
+
+}