DevBites

DevBites is a .NET MAUI app that delivers short, engaging programming concept cards in an infinite-scrolling feed.

It uses Microsoft.Extensions.AI (IChatClient) so the AI provider is swappable between Gemini and Ollama via .env config.

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Screenshots

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Feature Overview

• Infinite scrolling AI-generated feed
• Topic filter (.NET, Python, OOP, SOLID, Design Patterns, Data Structures)
• Expertise filter (Beginner, Medium, Advanced, Pro)
• Collapsible custom header
• Reusable card and header UI components (ContentView controls)
• Favorite reels (heart toggle per card)
• Persistent favorites stored locally in SQLite
• Feed/Favorites bottom tab bar UI
• AI provider switching through .env (gemini / ollama)
• Structured output enforcement using JSON schema via IChatClient response format

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Design Overview

DevBites uses an MVVM-first design that keeps UI, state, and data responsibilities separated.

UI Experience

• FeedPage hosts the complete screen layout, including:
  • collapsible top header
  • main content region
  • loading and error status area
  • bottom tab-style switch between Feed and Favorites
• FeedHeaderView is a reusable header component with topic and expertise pickers.
• ReelCardView is a reusable card component used in both feed and favorites lists.

State and Interaction

• FeedViewModel manages:
  • active reels and favorite reels
  • selected topic and expertise
  • pagination and cancellation logic
  • toggling favorites
  • switching between feed and favorites sections

Data and Persistence

• AIContentService requests and parses AI-generated reels.
• FavoritesService persists saved reels in local SQLite (devbites.db3).
• DotEnvLoader + Constants provide runtime config for provider/model settings.

AI Integration

• IChatClient abstraction keeps provider logic decoupled.
• Provider is selected at startup (gemini or ollama) from .env.
• JSON schema response format is applied to encourage strongly structured output.

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Key Components

Models/ProgrammingReel.cs

• Represents one concept card returned by AI
• Uses JsonPropertyName mappings
• Includes UI-only IsFavorite state (not serialized)

Services/AIContentService.cs

• Builds prompt using selected topic + expertise level
• Uses IChatClient.GetResponseAsync
• Enforces structured response format with JSON schema
• Parses response into List<ProgrammingReel>

IAIContentService signature:

Task<IReadOnlyList<ProgrammingReel>> GetReelsAsync(
    string topic,
    string expertiseLevel,
    CancellationToken cancellationToken = default);

Services/FavoritesService.cs

• Uses sqlite-net-pcl
• Stores favorites in local db file (devbites.db3)
• Supports toggle favorite, list favorites, and favorite-id lookup

ViewModels/FeedViewModel.cs

Main state + commands:

• Reels, FavoriteReels
• SelectedTopic, SelectedExpertiseLevel
• ShowFeedCommand, ShowFavoritesCommand
• ToggleFavoriteCommand
• LoadInitialCommand, LoadMoreCommand
• Cancellation-aware refresh when topic/expertise changes

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Configuration

The app loads .env from an embedded resource at startup.

Example:

AI_PROVIDER=gemini

GEMINI_API_KEY=your_key
GEMINI_MODEL=gemini-2.5-flash-lite

OLLAMA_ENDPOINT=http://localhost:11434
OLLAMA_MODEL=llama3.2

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AI Provider Setup

Gemini (default)

1. Create API key: https://aistudio.google.com/app/apikey
2. Set in .env:

AI_PROVIDER=gemini
GEMINI_API_KEY=your_key
GEMINI_MODEL=gemini-2.5-flash-lite

Ollama (local)

1. Install Ollama: https://ollama.com
2. Pull model:

ollama pull llama3.2

3. Set in .env:

AI_PROVIDER=ollama
OLLAMA_ENDPOINT=http://localhost:11434
OLLAMA_MODEL=llama3.2

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Getting Started

# 1) restore
dotnet restore

# 2) build
dotnet build

# 3) run Android
dotnet build -t:Run -f net10.0-android

# 4) run Windows
dotnet build -t:Run -f net10.0-windows10.0.19041.0

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Dependency Injection Map

Registered as	Concrete type	Lifetime
IChatClient	GeminiChatClient or OllamaApiClient	Singleton
IAIContentService	AIContentService	Singleton
IFavoritesService	FavoritesService	Singleton
FeedViewModel	FeedViewModel	Transient
FeedPage	FeedPage	Transient

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Tech Stack

• .NET 10
• .NET MAUI
• CommunityToolkit.Mvvm
• Microsoft.Extensions.AI
• GeminiDotnet.Extensions.AI
• OllamaSharp
• sqlite-net-pcl