The Considerations in Building PWA For A Blogger Blog Using Firebase Studio

Introduction

Building on the success of creating a drug database app using Firebase Studio, I decided to take on a new challenge - developing an offline-first PWA for my existing blog.

• Truth be told, even with some prior experience, this new project introduced more complexities and considerations than the previous one, making it another rewarding yet demanding endeavor.

Setting Up in Firebase Studio

To quickly prototype a user interface, you can use the App Prototyping Agent in Firebase Studio, which supports natural language prompts for layout generation.

• The core framework of this Blogger PWA relies on the Blogger API v3 to fetch both blog posts and static pages from a specified Blogger blog, sync the content into IndexedDB, and render it within the app.

Technically, to use the Blogger API v3 to fetch the data, you do not have to be the owner of the blog. On the other hand, you need three key things:

• Blog ID
• This unique identifier is crucial for targeting the correct blog.
• If you are the blog owner, you can find this backend URL in Blogger dashboard (e.g., https://draft.blogger.com/u/blog/posts/1234567890123456789).
• Otherwise, inspect the page source and look for the feed URL:
• https://www.blogger.com/feeds/1234567890123456789/posts/default.
• Blog URL
• The public-facng URL of the blog: https://XXXXXX.blogspot.com/
• A Google API key
• A Google API key can be created in the Google Cloud Console by navigating to APIs & Services > Library, enabling the Blogger API, and then generating an API key under APIs & Services > Credentials.

However, as an author, you will have the ability to format blog content and customize the appearance of articles more freely.

• Additionally, you can create a Table of Contents page with <h2> tags for chapters, <h4> for subchapters, and linked text as topics.
• This structure allows the app to dynamically build a sidebar navigation menu with chapter-subchapter-topic hierarchy.
• However, the parsing logic must be robust enough to handle variations, such as extra <p> tags or other elements between headings, to avoid breaking the navigation hierarchy.

Syncing To IndexedDB

Many Blogger blogs include both posts and static pages.

• Posts typically follow a slug URL like: https://XXX.blogspot.com/YYYY/MM/title.html, while pages follow a simpler path: https://XXX.blogspot.com/p/title.html.
• Therefore, syncing these contents often requires separate fetch operations using posts/bypath and pages/bypath.

Another crucial design decision involves how content is identified and stored in IndexedDB.

• While numerical page or post IDs are the most reliable primary keys for database entries, ensuring fast lookups and data integrity, but they are not human-readable.
• On the other hand, slug paths are human-readable and essential for resolving internal links within the blog content.
• The best approach is to store both, using the ID as the primary key and creating a separate index on the path for efficient lookups when a user clicks an internal link.

Where possible, internal blog links should be resolved by path, fetched, cached in IndexedDB, and rendered entirely on the client.

• Implementing a cache-first with stale-while-revalidate strategy ensures fast load times while keeping content fresh when online.

Because blog content can be created or deleted at any time, simply fetching content based on a lastUpdated timestamp is unreliable as it will miss deletions. A more resilient "delta" sync process is required:

• Fetch all blog posts and pages in bulk
• Compare them against the IndexedDB content
• Perform delta operations, such as add, update or remove as needed

Fortunately, the Blogger API v3 has generous quotas of 10,000 requests/day, which are more than sufficient for personal use.

Content Renderer Setup

Unlike the structured format of a drug database app, rendering blog content requires more attention to typography, image placement, and layout consistency. Some enhancements to consider:

• Theme toggles (e.g., light/dark modes)
• Font size controls for better readability
• Global search across all blog topics
• In-page search within individual posts or pages
• Image alignment logic that respects Blogger’s original formatting

Offline Support

To ensure seamless offline access, the app must:

• Fully sync blog posts and pages into indexedDB
• Use service workers to cache the app shell (HTML, CSS, JS, Next.js chunks)
• Include a valid web app manifest

Additionally, creating a build script to prefetch all content and package it into a JSON file for deployment is a great way to reduce the initial load hit when the app is first launched.

Keep in mind that blog content is not limited to plain text. It may include embedded images, YouTube videos and other interactive media.

• To manage these gracefully, lazy loading with fallback placeholders strategy is essential - especially for offline or slow-network scenarios.

Summary

The goal of this post is not to convince you to build a PWA for any Blogger blog, because many may not justify the time and effort. Instead, it aims to highlight that different types of apps demand different design and development considerations.

• While a database-driven app focuses on data accuracy and structure, a content-rich blog PWA emphasizes layout, navigation, media rendering, and offline accessibility due to its dynamic user-generated content.
• Another serious security consideration is protecting your Blogger API key. In production environments, it is recommended to store the key in environment variables rather than hardcoding it. During local development, you can use .env files (which should be included in .gitignore), while in production, you can configure environment variables via the apphosting.yaml file and manage secrets securely using Google Secret Manager when deploying to Firebase App Hosting.

One final tip for any app development journey: while refining the logic can take endless time, a detailed console log is often the most revealing tool for discovering what went wrong.

• This is especially true for subtle bugs, which frequently appear when two perfectly functional components create a race condition, or a syntax mismatch.