DEV Community: Sasha Kovalchuk

How to Update a Chrome Extension from Manifest V2 to V3: A Step-by-Step Guide Using a Pomodoro Timer Example

Sasha Kovalchuk — Fri, 30 Aug 2024 07:32:40 +0000

Updating a Chrome extension from Manifest V2 to Manifest V3 is a critical step for developers, as Google has phased out support for Manifest V2. In this article, we’ll walk through the process of upgrading a Pomodoro Timer extension, originally built with Manifest V2, to the newer Manifest V3 standard.

My story

I had a Pomodoro Timer extension that I made 4 years ago for nothing and I got a notification from Google that I needed to update Manifest.

The original version of my Pomodoro Timer was something I designed myself, with a T-Rex roar as the end-of-cycle notification 🦖. It was quirky and fun, I was even surprised to see 24 people using it.

This is what it looked like:

My wife recently started learning design and since I need to update Manifest I asked her to freshen up the design. The result is at the end of the article. Spoiler: I think it turned out great.

Why Upgrade to Manifest V3?

Manifest V3 introduces several key changes aimed at enhancing privacy, security, and performance in Chrome extensions. These changes include:

Service Workers: Background pages are replaced with service workers, which are more efficient because they don’t run continuously.
Enhanced Security: Reduced permission scopes and the introduction of the declarativeNetRequest API to manage network requests.
Improved Performance: By optimizing how extensions interact with browser resources, V3 ensures better resource management.

Step 1: Understanding the Core Differences

Before diving into the update, it’s important to understand the key changes between Manifest V2 and V3:

Background Scripts: In V2, background scripts ran continuously. In V3, these are replaced with service workers that run only when needed.
Permissions: Manifest V3 requires explicit declaration of all permissions, and certain permissions have been deprecated or replaced.
API Changes: Some APIs have been removed or replaced, and the messaging system between different components of the extension has been updated.

Step 2: Updating the Manifest File

Here’s how you would update the manifest.json file from V2 to V3 for a Pomodoro Timer extension:

Original Manifest V2 Example:

{
  "name": "Pomodoro Clock",
  "version": "1.1.0",
  "description": "Simple background timer for productivity",
  "manifest_version": 2,
  "permissions": ["storage"],
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "img/tomato16.png",
      "32": "img/tomato32.png",
      "48": "img/tomato48.png",
      "128": "img/tomato128.png"
    }
  },
  "icons": {
    "16": "img/tomato16.png",
    "32": "img/tomato32.png",
    "48": "img/tomato48.png",
    "128": "img/tomato128.png"
  },
  "background": {
    "scripts": ["background.js"]
  },
  "options_page": "options.html"
}

Updated Manifest V3 Example:

{
  "name": "Pomodoro Timer & Focus Clock",
  "version": "2.0.1",
  "description": "Boost productivity with this simple Pomodoro timer. Focus on tasks, minimize distractions, and manage your time effectively.",
  "manifest_version": 3,
  "permissions": ["storage","notifications","alarms"],
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "img/tomato16.png",
      "32": "img/tomato32.png",
      "48": "img/tomato48.png",
      "128": "img/tomato128.png"
    }
  },
  "icons": {
    "16": "img/tomato16.png",
    "32": "img/tomato32.png",
    "48": "img/tomato48.png",
    "128": "img/tomato128.png"
  },
  "background": {
    "service_worker": "background.js"
  }
}

Key Changes in the Manifest:

Background Script:

V2: "background": {"scripts": ["background.js"]}
V3: "background": {"service_worker": "background.js"}

In V3, background scripts are replaced with service workers. Service workers only run when necessary, improving resource efficiency.

Action vs. Browser Action:

V2: "browser_action": { ... }
V3: "action": { ... }

browser_action has been replaced by action, which consolidates functionality and simplifies the manifest.

Step 3: Updating the Background Script to Use Service Workers

My extension used a simple setInterval() in background, with service worker this behavior will not work, because to save browser resources it runs only when needed.

In my case I had to modify the timer and store the timestamp in storage, use alarms to schedule the triggering code of the notification caller to run.

And of course used chrome's built-in notifications to send notifications to get rid of annoying t-rex rear. If I'm read by early users of my extension, I'm really sorry about that 😅

There will not be a code example here as it is too specific.

Conclusion

Here's the result. I think it's pretty cool. Minimalistic and easy to use

The update was not that difficult, the main thing is to understand the difference between an old background script and a service worker, but be careful with Alarms, I even managed to crash Chrome a couple times while testing 😄

Feel free to try the updated Pomodoro Timer & Focus Clock extension and good luck with updating yours!

Creating an auto-scrolling Сarousel component using FlashList in React Native

Sasha Kovalchuk — Fri, 05 Apr 2024 13:35:30 +0000

We all love FlashList, it is a great and modern replacement for FlatList. Like FlatList, FlashList supports horizontal scrolling and we can quite easily use it as a carousel. The purpose of my article is to show exactly what can be done and add automatic scrolling of carousel components

Creating the Carousel Component

First, let's make a Carousel component using FlashList from Shopify. For simplicity of the example, the Props of our component will correspond to FlashListProps

Here's a setup:

import React, { useRef } from 'react'
import { FlashList, FlashListProps } from '@shopify/flash-list'

export const Carousel = (props: FlashListProps) => {
  const carouselRef = useRef<FlashList>(null)

  return (
    <FlashList
      ref={carouselRef}
      {...props}
      showsHorizontalScrollIndicator={false}
      decelerationRate={'fast'}
      pagingEnabled
      horizontal
    />
  )
}

Adding Auto Scrolling

Now let's make the Carousel autoscrollable. In our example, the carousel will stop at the end, but you can easily change the code and return it to the first element if needed

Look at this part:

...
const AUTO_SCROLL_INTERVAL = 5000

export const Carousel = (props: FlashListProps) => {
  ...
  const autoScrollTimerRef = useRef<ReturnType<typeof setTimeout>>()
  const [autoScroll, setAutoScroll] = useState(true)
  const [visibleItemIndex, setVisibleItemIndex] = useState(0)

  const handleViewableItemsChanged = useCallback(
    ({ viewableItems }: { viewableItems: ViewToken[] }) => {
      const firstVisibleItemIndex = viewableItems?.[0]?.index
      const lastDataIndex = props.data.length - 1

      // remove this if your carousel should not stop
      if (firstVisibleItemIndex === lastDataIndex) {
        setAutoScroll(false)
      }

      if (typeof firstVisibleItemIndex === 'number') {
        setVisibleItemIndex(firstVisibleItemIndex)
      }
    },
    [props.data]
  )

  useEffect(() => {
    if (autoScroll) {
      const nextItemIndex = visibleItemIndex + 1
      const hasNextItem = !!props.data?.[nextItemIndex]

      if (hasNextItem) {
        autoScrollTimerRef.current = setTimeout(() => {
          carouselRef.current?.scrollToIndex({
            index: nextItemIndex,
            animated: true,
          })
        }, AUTO_SCROLL_INTERVAL)
      } else {
        // here you can return the carousel to the beginning if needed
      }
    }
  }, [autoScroll, props.data, visibleItemIndex])

  return (
    <FlashList
      ref={carouselRef}
      {...props}
      ...
      onViewableItemsChanged={handleViewableItemsChanged}
    />
  )
}

Why do we need handleViewableItemsChanged? So we will always know in the code which item the user sees at the moment. Don't forget that the user can scroll our carousel manually, see the next section on how to control this

User Interaction with auto scrolling

Users might want to look longer at an item. When they touch the Carousel, we should stop auto-scrolling. When they stop touching, it starts moving again. We'll even add a delay after which the carousel will start scrolling again on its own

Here's how:

...
const AUTO_SCROLL_PAUSE = 5000

export const Carousel = (props: FlashListProps) => {
  ...
  const userTouchTimerRef = useRef<ReturnType<typeof setTimeout>>()

  const handleUserAnyTouch = useCallback(() => {
    clearTimeout(autoScrollTimerRef.current)
    clearTimeout(userTouchTimerRef.current)
    setAutoScroll(false)

    userTouchTimerRef.current = setTimeout(() => {
      setAutoScroll(true)
    }, AUTO_SCROLL_PAUSE)
  }, [])

  return (
    <FlashList
      ref={carouselRef}
      {...props}
      ...
      onTouchStart={handleUserAnyTouch}
    />
  )
}

Conclusions

I tried to show that making such an important interactive element as Carousel is not difficult. You can use it as a starting point

You can see the final code as a ready-to-use library here:

github
npm

Some optimizations have already been added there in the form of memoization of necessary pieces of code, clearing timers when the component is destroyed, and others. You can use this library in your own projects or use the developments we have discussed here to make your own

In any case, I will be glad to receive your stars on github, comments and questions here. Cheers!