News Reader

Overview

News Reader is an iOS application designed to fetch and display dynamic news articles, offering features like voice synthesis of articles, image loading with caching, and integration with various services like AWS Polly for text-to-speech functionality.

The app uses pagination to load articles dynamically, integrates SDWebImage for efficient image loading and caching, and stores user preferences and cached data locally using Core Data. Additionally, the app adapts to both light and dark modes using dynamic colors to provide a visually appealing experience.

Features

• Dynamic Feed: Fetches news articles dynamically based on user scrolling behavior.
• Voice Synthesis: Uses AWS Polly to synthesize article summary into speech for hands-free reading.
• Image Loading & Caching: Efficiently loads and caches article images using SDWebImage.
• Dark Mode Support: Adapts UI colors for both light and dark mode.
• Core Data Integration: Caches articles and related data for offline use.
• Subscription Support: Handles varying page sizes based on the user's subscription model.
• Asynchronous Data Fetching: Fetches data asynchronously to maintain a smooth user experience.
• Caching: Utilizes caching for both API and local data to improve performance.

Installation

1. Clone the repository:

   git clone https://github.com/ganapathy-shan/News-Reader.git
   

2. Install dependencies using CocoaPods:

   • Make sure you have CocoaPods installed. If not, you can install it using:

     bash

     Copy code

     sudo gem install cocoapods

   • Navigate to the project directory and run:

     bash

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     pod install

3. Open the project:

   • Open the .xcworkspace file in Xcode:

     open NewsReader.xcworkspace

Configure API and AWSPolly

1. OpenAI API Key

How to Get:

1. Visit the OpenAI website: https://platform.openai.com/signup.
2. Sign up for an account or log in if you already have one.
3. Go to the API Keys section from your account settings: OpenAI API Keys.
4. Click Create new secret key.
5. Copy the generated API key.

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2. NewsAPI Key

How to Get:

1. Visit the NewsAPI website: https://newsapi.org/.
2. Sign up for an account or log in if you already have one.
3. Go to the API Keys section.
4. Click Get API Key and copy the key.

Where to Replace in Code:

• These keys will be placed in the config.plist file (explained in Step 4).

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3. Steps to Configure IAM Role for Full Polly Access

Create a New IAM Role in AWS Console:

1. Go to the IAM Console: AWS IAM Console.
2. On the left-hand side, select Roles.
3. Click Create role.
4. For the trusted entity, select Cognito as the service that will use this role.
5. Under Use case for the role, choose Cognito Identity Pool.
6. Click Next: Permissions.

Attach Polly Permissions to the Role:

1. In the permissions search box, search for Polly.
2. From the list, select AmazonPollyFullAccess.
3. Click Next: Tags, then Next: Review.
4. Give the role a meaningful name like CognitoPollyFullAccessRole.
5. Click Create role.

Assign the Role to the Cognito Identity Pool:

1. Go to the Amazon Cognito Console: AWS Cognito Console.
2. Select Manage Identity Pools from the navigation.
3. Choose the Identity Pool you want to assign the role to.
4. In the Identity Pool settings, click Edit Identity Pool.
5. Under Authentication Providers, select the role CognitoPollyFullAccessRole for both Authenticated and Unauthenticated Role.
6. Click Save Changes.

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4. Create config.plist in Xcode and Add API Keys

Steps to Create the config.plist File:

1. Open your project in Xcode.
2. In the Project Navigator, right-click on the "News Reader" folder.
3. Select New File....
4. Choose Property List under the iOS > Resource category.
5. Name the file config.plist and click Create.

Add Keys:

Create 3 rows in config.plist with following keys OpenAPIKey NewsAPIKey AWSPoolID

Update the Key Values:

• Replace the value for:
  • OpenAPIKey: Paste the OpenAI API key.
  • NewsAPIKey: Paste the NewsAPI key.
  • AWSPoolID: Enter your Cognito Identity Pool ID.

Technologies Used

• Swift: The primary language used for development.
• AWS Polly: Used for text-to-speech synthesis to read news articles summary aloud.
• SDWebImage: Used for asynchronous image loading and caching.
• Core Data: Used for caching and local storage.
• CocoaPods: Dependency management for libraries like AWSMobileClient and AWSPolly.

Usage

1. Fetching News: Articles are fetched dynamically based on user scrolling. The app will load articles in batches and cache them for offline viewing.

2. Reading Articles Aloud: Once an article is displayed, users can click on the speaker button to have the article's summary synthesized into speech.

3. Dark Mode: The app adapts its interface for both light and dark mode. Text and background colors will change based on the user's system preference.

Key Components

1. FeedViewController

The FeedViewController is responsible for managing the display of news articles. It contains the table view, handles user interactions like scrolling, and triggers the fetching of new articles as the user reaches the end of the list. This controller also interacts with the FeedViewModel to fetch and update the articles dynamically.

Key functionalities:

• Table view setup and configuration.
• Handles scrolling behavior to fetch new articles dynamically.
• Updates the UI with fetched articles.
• Displays errors if any occur during data fetching.

2. FeedViewModel

The FeedViewModel acts as the intermediary between the FeedViewController and the data sources (e.g., network APIs, Core Data). It manages the fetching, processing, and caching of news articles. The view model handles dynamic pagination and ensures that the feed is updated with new articles as the user scrolls. It also manages cache and handles missing data.

Key functionalities:

• Fetches news articles dynamically from both the cache and the network.
• Handles pagination and determines the page size based on the user's subscription.
• Updates the feedItems list asynchronously when new data is fetched.
• Handles errors and updates the UI with appropriate feedback.
• Is actor-isolated for thread safety in handling feedItems.

3. FeedCell

The FeedCell is a custom table view cell that displays individual news articles. It contains elements like the article's title, description, image thumbnail, and a speaker button for text-to-speech functionality. The cell is designed to be reused efficiently with dynamic content that adjusts based on the data provided.

Key functionalities:

• Displays the article's title, description, and image.
• Supports lazy image loading and caching using SDWebImage.
• Provides a speaker button to trigger text-to-speech functionality (using AWS Polly).
• Adapts layout based on content size, utilizing UITableView.automaticDimension for dynamic cell heights.

4. ContentSynthesizer

The ContentSynthesizer is responsible for converting the content of articles into speech using AWS Polly. Once a user taps the speaker button on a FeedCell, the article's text is sent to AWS Polly, which returns an audio stream that is played back to the user.

Key functionalities:

• Converts article text to speech using AWS Polly.
• Manages playback of the synthesized audio.
• Provides an interface for starting and stopping speech playback.

5. WebContentExtractor

WebContentExtractor is a utility responsible for extracting clean content from URLs. When a user selects an article, the extractor fetches the raw content (e.g., the article body) from the web page. The cleaned-up content is then passed to the summarizer (OpenAI API) for summarization or directly displayed in the app.

Key functionalities:

• Fetches and cleans up article content from the web.
• Integrates with external APIs for content extraction.

6. SummaryCacheManager

The SummaryCacheManager is used to cache the summarized versions of articles. By caching these summaries, the app avoids re-fetching and re-processing the same content. This improves app performance and provides a faster user experience.

Key functionalities:

• Caches the summaries for articles to prevent repeated fetches.
• Retrieves summaries from the cache before fetching new ones.
• Allows easy management of cached content.

Architecture

The architecture of the News Reader app follows Clean Architecture principles along with the MVVM (Model-View-ViewModel) pattern. The app emphasizes separation of concerns, scalability, and testability by organizing the code into distinct layers. Additionally, it employs the Coordinator pattern to manage the flow and navigation of the app.

Model

• FeedItem: Represents a single news article with properties such as title, description, image URL, and content. This model is used across different layers of the app to represent articles.
• Cache Manager: A service responsible for managing and retrieving cached articles from Core Data, ensuring that previously fetched data is available offline.

View

• FeedViewController: The main view controller displaying the list of articles. It interacts with the FeedViewModelto fetch data and updates the UI accordingly.
• FeedCell: A custom table view cell that displays individual articles with elements like the title, description, image thumbnail, and a speaker button to trigger text-to-speech.

ViewModel

• FeedViewModel: Acts as an intermediary between the view and the data layers, handling fetching, processing, and updating the UI. It also manages dynamic pagination, caching, and error handling.
• ContentSynthesizer: A ViewModel that is responsible for converting article text into speech using AWS Polly. It isolates the text-to-speech logic from the rest of the app and allows for starting and stopping speech playback.

Service Layer

• OpenAIAPIManager: A service for interacting with OpenAI's API to summarize article content. After extracting raw content via the WebContentExtractor, the summary is sent to OpenAI for processing and returned to the app for display.
• FeedService: A service responsible for handling network requests to fetch articles. It interacts with APIs to fetch articles and integrates with the CacheManager to cache articles for offline use.
• CacheManager: Manages caching operations by saving and retrieving articles to and from Core Data. It ensures articles are available even when the app is offline.
• ContentSynthesizer: Handles converting text into speech using AWS Polly. It is a service that manages the interaction with AWS and playback functionality for articles.
• CoreDataManager: Responsible for managing interactions with Core Data, handling the saving, retrieving, and deleting of articles and other data entities.

Coordinator

• AppCoordinator: The root coordinator that manages the initial setup of the app and coordinates the flow to the main feed screen.
• FeedCoordinator: Responsible for managing navigation within the feed section, such as transitioning to article details or managing other transitions.

Data Flow

1. Fetching Data: The FeedViewModel interacts with FeedService to fetch articles from a remote API. If no network is available, CacheManager retrieves articles from Core Data. The WebContentExtractor fetches and cleans article content, which is either displayed directly or passed to OpenAIAPIManager for summarization.
2. Updating the UI: Once new data is fetched, the FeedViewModel updates the FeedViewController with the articles, which are then displayed in a table view.
3. Handling Errors: If errors occur during data fetching (e.g., network errors), the FeedViewModel handles them and updates the FeedViewController with appropriate error messages.
4. Text-to-Speech: When the user taps the speaker button on a FeedCell, the FeedViewModel communicates with ContentSynthesizer, which uses AWS Polly to convert the article text to speech and manage playback.

Clean Architecture Flow

1. Model Layer: Includes FeedItem, CacheManager, FeedService, CoreDataManager, and OpenAIAPIManager. These components handle data storage, networking, content extraction, and API calls.
2. ViewModel Layer: The FeedViewModel manages data fetching, dynamic pagination, and updates the UI. It interacts with the ContentSynthesizer for text-to-speech conversion and uses the FeedService for data fetching.
3. View Layer: FeedViewController and FeedCell manage UI presentation. The view layer listens for updates from the FeedViewModel and binds the data to UI elements.
4. Service Layer: The FeedService, OpenAIAPIManager, CacheManager, ContentSynthesizer, and CoreDataManager provide necessary services like data fetching, content summarization, caching, and text-to-speech functionality. These services are separated from the ViewModel and View, promoting better testability and reusability.
5. Coordinator Layer: The AppCoordinator and FeedCoordinator manage the app's navigation, decoupling the navigation logic from the view controllers and making the flow more manageable.

The app also supports asynchronous data fetching using Swift's concurrency features, ensuring that the UI remains responsive while data is being loaded in the background.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgements

• AWS Polly for providing text-to-speech capabilities.
• SDWebImage for providing a powerful image caching and loading library.
• Thanks to the contributors and open-source community for their continuous support.

Contributing

Feel free to fork this project, submit issues, or open pull requests for improvements! Contributions are always welcome.