Dioxus Provider

⚠️ In Development
This library is currently in active development. The API may change before the first stable release. Please check the changelog for the latest updates and breaking changes.

Effortless, powerful, and scalable data fetching and caching for Dioxus applications, inspired by Riverpod for Flutter.

dioxus-provider provides a simple yet robust way to manage data fetching, handle asynchronous operations, and cache data with minimal boilerplate. It is designed to feel native to Dioxus, integrating seamlessly with its component model and hooks system.

Key Features

Data Fetching & Caching

• Global Provider System: Manage application-wide data without nesting context providers. Simplifies component architecture and avoids "provider hell."
• Declarative #[provider] Macro: Define data sources with a simple attribute. The macro handles all the complex boilerplate for you.
• Intelligent Caching Strategies:
  • Stale-While-Revalidate (SWR): Serve stale data instantly while fetching fresh data in the background for a lightning-fast user experience.
  • Time-to-Live (TTL) Cache Expiration: Automatically evict cached data after a configured duration.
• Automatic Refresh: Keep data fresh with interval-based background refetching.
• Parameterized Queries: Create providers that depend on dynamic arguments (e.g., fetching user data by ID).

Composable Providers ✨ NEW!

• Parallel Execution: Run multiple providers simultaneously with compose = [provider1, provider2, ...] for significant performance gains.
• Type-Safe Composition: Automatic result combination with compile-time safety guarantees.
• Flexible Composition: Compose any subset of providers based on your specific needs.
• Error Aggregation: Intelligent error handling across composed providers with proper error propagation.

Structured Error Handling ✨ NEW!

• Rich Error Types: Comprehensive error hierarchy with ProviderError, UserError, ApiError, and DatabaseError.
• Actionable Error Messages: Context-rich error information for better debugging and user feedback.
• Error Chaining: Automatic error conversion and chaining using #[from] attributes.
• Backward Compatibility: Seamless integration with existing String-based error handling.

Mutation System

• Manual Implementation Pattern: Define data mutations using simple struct implementations.
• Optimistic Updates: Immediate UI feedback with automatic rollback on failure.
• Smart Cache Invalidation: Automatically refresh related providers after successful mutations.
• Mutation State Tracking: Built-in loading, success, and error states for mutations.
• Type-Safe Parameters: Support for no parameters, single parameters, and multiple parameters (tuples).

Developer Experience

• Manual Cache Control: Hooks to manually invalidate cached data or clear the entire cache.
• Cross-Platform by Default: Works seamlessly on both Desktop and Web (WASM).
• Minimal Boilerplate: Get started in minutes with intuitive hooks and macros.
• Type Safety: Full TypeScript-level type safety with Rust's type system.

Installation

Add dioxus-provider to your Cargo.toml:

[dependencies]
dioxus-provider = "0.0.1" # Replace with the latest version

Getting Started

1. Initialize Global Providers

At the entry point of your application, call init_global_providers() once. This sets up the global cache that all providers will use.

use dioxus_provider::global::init_global_providers;
use dioxus::prelude::*;

fn main() {
    // This is required for all provider hooks to work
    init_global_providers();
    launch(app);
}

fn app() -> Element {
    rsx! { /* Your app content */ }
}

2. Create a Provider

A "provider" is a function that fetches or computes a piece of data. Use the #[provider] attribute to turn any async function into a data source that can be used throughout your app.

use dioxus_provider::prelude::*;
use std::time::Duration;

// This could be an API call, database query, etc.
#[provider]
async fn get_server_message() -> Result<String, String> {
    // Simulate a network request
    tokio::time::sleep(Duration::from_secs(1)).await;
    Ok("Hello from the server!".to_string())
}

3. Use the Provider in a Component

Use the use_provider hook to read data from a provider. Dioxus will automatically re-render your component when the data changes (e.g., when the async function completes).

The hook returns a Signal<ProviderState<T, E>>, which can be in one of three states: Loading, Success(T), or Error(E).

use dioxus::prelude::*;
use dioxus_provider::prelude::*;

#[component]
fn App() -> Element {
    // Use the provider hook to get the data
    let message = use_provider(get_server_message(), ());

    rsx! {
        div {
            h1 { "Dioxus Provider Demo" }
            // Pattern match on the state to render UI
            match &*message.read() {
                ProviderState::Loading { .. } => rsx! { div { "Loading..." } },
                ProviderState::Success(data) => rsx! { div { "Server says: {data}" } },
                ProviderState::Error(err) => rsx! { div { "Error: {err}" } },
            }
        }
    }
}

Mutations: Modifying Data with Automatic Cache Management

The mutation system allows you to define data modification operations that automatically invalidate related provider caches, ensuring your UI stays in sync with server state.

1. Basic Mutations (Macro-Based)

Create mutations using the #[mutation] attribute. Mutations automatically invalidate specified provider caches when they succeed.

use dioxus_provider::prelude::*;

// Define a mutation that invalidates the todo list when successful
#[mutation(invalidates = [fetch_todos])]
async fn add_todo(title: String) -> Result<Todo, String> {
    // ... add todo logic ...
}

// Use the mutation in a component
let (mutation_state, mutate) = use_mutation(add_todo());

2. Optimistic Updates

For better UX, use optimistic mutations that update the UI immediately and rollback on failure:

#[mutation(invalidates = [fetch_todos])]
async fn toggle_todo(id: u32) -> Result<Todo, String> {
    // ... toggle logic ...
}

let (mutation_state, toggle) = use_optimistic_mutation(toggle_todo());

3. Multiple Cache Invalidation

Mutations can invalidate multiple provider caches at once:

#[mutation(invalidates = [fetch_todos, fetch_stats])]
async fn remove_todo(id: u32) -> Result<(), String> {
    // ... remove logic ...
}

New Features in Latest Release

Composable Providers: Parallel Data Loading

Run multiple providers simultaneously for better performance:

// These providers will run in parallel
#[provider(compose = [fetch_user, fetch_permissions, fetch_settings])]
async fn fetch_complete_profile(user_id: u32) -> Result<UserProfile, ProviderError> {
    // Results are automatically available as:
    // - __dioxus_composed_fetch_user_result: Result<User, ProviderError>
    // - __dioxus_composed_fetch_permissions_result: Result<Permissions, ProviderError>
    // - __dioxus_composed_fetch_settings_result: Result<Settings, ProviderError>
    
    let user = __dioxus_composed_fetch_user_result?;
    let permissions = __dioxus_composed_fetch_permissions_result?;
    let settings = __dioxus_composed_fetch_settings_result?;
    
    Ok(UserProfile { user, permissions, settings })
}

Structured Error Handling

Rich, actionable error types for better error handling:

use dioxus_provider::prelude::*;

#[provider]
async fn fetch_user_data(id: u32) -> Result<User, UserError> {
    if id == 0 {
        return Err(UserError::ValidationFailed {
            field: "id".to_string(),
            reason: "ID cannot be zero".to_string(),
        });
    }
    
    match api_client.get_user(id).await {
        Ok(user) if user.is_suspended() => Err(UserError::Suspended {
            reason: "Account temporarily suspended".to_string(),
        }),
        Ok(user) => Ok(user),
        Err(_) => Err(UserError::NotFound { id }),
    }
}

// Error types available: ProviderError, UserError, ApiError, DatabaseError
// Full backward compatibility with String errors

Advanced Usage

Parameterized Providers

Providers can take arguments to fetch dynamic data. For example, fetching a user by their ID. The cache is keyed by the arguments, so fetch_user(1) and fetch_user(2) are cached separately.

use dioxus_provider::prelude::*;

#[provider]
async fn fetch_user(user_id: u32) -> Result<String, String> {
    Ok(format!("User data for ID: {}", user_id))
}

#[component]
fn UserProfile(user_id: u32) -> Element {
    // Pass arguments as a tuple
    let user = use_provider(fetch_user(), (user_id,));

    match &*user.read() {
        ProviderState::Success(data) => rsx!{ div { "{data}" } },
        // ... other states
        _ => rsx!{ div { "Loading user..." } }
    }
}

Caching Strategies

Stale-While-Revalidate (SWR)

stale_time serves cached (stale) data first, then re-fetches in the background. This provides a great UX by showing data immediately.

#[provider(stale_time = "10s")]
async fn get_dashboard_data() -> Result<String, String> {
    // ... fetch data
    Ok("Dashboard data".to_string())
}

Cache Expiration (TTL)

cache_expiration evicts data from the cache after a time-to-live (TTL). The next request will show a loading state while it re-fetches.

// This data will be removed from cache after 5 minutes of inactivity
#[provider(cache_expiration = "5m")]
async fn get_analytics() -> Result<String, String> {
    // ... perform expensive analytics query
    Ok("Analytics report".to_string())
}

Manual Cache Invalidation

You can manually invalidate a provider's cache to force a re-fetch.

use dioxus::prelude::*;
use dioxus_provider::prelude::*;

#[component]
fn UserDashboard() -> Element {
    let user_data = use_provider(fetch_user(), (1,));
    let invalidate_user = use_invalidate_provider(fetch_user(), (1,));

    rsx! {
        // ... display user_data
        button {
            onclick: move |_| invalidate_user(),
            "Refresh User"
        }
    }
}

To clear the entire global cache for all providers:

let clear_cache = use_clear_provider_cache();
clear_cache();

Running The Examples

The examples directory contains comprehensive demos covering all library features.

Core Features

• comprehensive_demo.rs: Showcases all provider features working together. A great place to start!
• counter_mutation_demo.rs: Complete mutation system demo with optimistic updates and cache invalidation.

Error Handling & Composition

• structured_errors_demo.rs: NEW! Demonstrates comprehensive structured error handling with ProviderError, UserError, ApiError, and DatabaseError types. Shows proper error UI feedback and validation patterns.
• composable_provider_demo.rs: NEW! Showcases parallel provider composition for performance optimization. Demonstrates how to run multiple providers simultaneously and combine their results.
• dependency_injection_demo.rs: Shows manual dependency injection patterns with inject::<Type>() for clean provider architecture.

Caching & Performance

• swr_demo.rs: Focuses on the Stale-While-Revalidate pattern for instant data loading.
• cache_expiration_demo.rs: Demonstrates TTL-based cache expiration strategies.
• interval_refresh_demo.rs: Shows automatic background data refreshing with configurable intervals.

To run an example:

# Run the comprehensive demo (recommended starting point)
cargo run --example comprehensive_demo

# Try the new error handling demo
cargo run --example structured_errors_demo

# See parallel provider composition in action
cargo run --example composable_provider_demo

# Or run any specific demo
cargo run --example swr_demo
cargo run --example counter_mutation_demo
cargo run --example dependency_injection_demo

Ecosystem & Alternatives

dioxus-query: For Complex, Type-Safe Data Management

For more complex applications requiring advanced type safety, sophisticated caching strategies, and enterprise-grade data management, we highly recommend dioxus-query by Marc.

dioxus-query is a mature, production-ready library that provides:

• Advanced Type Safety: Compile-time guarantees for complex data relationships
• Sophisticated Caching: Multi-level caching with intelligent invalidation strategies
• Query Dependencies: Automatic dependency tracking and cascading updates
• Optimistic Updates: Immediate UI updates with rollback on failure
• Background Synchronization: Advanced background sync with conflict resolution
• Enterprise Features: Built-in support for complex data patterns and edge cases

When to choose dioxus-query:

• Large-scale applications with complex data requirements
• Teams requiring maximum type safety and compile-time guarantees
• Applications with sophisticated caching and synchronization needs
• Enterprise applications where data consistency is critical

When to choose dioxus-provider:

• Smaller to medium applications
• Quick prototyping and development
• Teams new to Dioxus data management
• Applications where simplicity and ease of use are priorities

dioxus-motion: For Smooth Animations and Transitions

Looking to add beautiful animations to your Dioxus application? Check out dioxus-motion - a lightweight, cross-platform animation library also built by me.

dioxus-motion provides:

• Cross-Platform Animations: Works seamlessly on web, desktop, and mobile
• Declarative Animation API: Write animations as data, not imperative code
• Page Transitions: Smooth route transitions with AnimatedOutlet
• Spring Physics: Natural, physics-based animations
• Custom Easing: Extensive easing function support
• Type-Safe Animations: Compile-time animation safety
• Extensible: Implement Animatable trait for custom types

Perfect combination:

• Use dioxus-provider for data fetching and caching
• Use dioxus-motion for smooth UI animations and transitions
• Both libraries work together seamlessly in the same application

// Example: Combining dioxus-provider with dioxus-motion
use dioxus_provider::prelude::*;
use dioxus_motion::prelude::*;

#[component]
fn AnimatedUserCard(user_id: u32) -> Element {
    // Data fetching with dioxus-provider
    let user_data = use_provider(fetch_user(), (user_id,));
    
    // Animation with dioxus-motion
    let scale = use_motion(1.0f32);
    
    match &*user_data.read() {
        ProviderState::Success(user) => rsx! {
            div {
                style: "transform: scale({scale.get_value()})",
                onclick: move |_| {
                    scale.animate_to(1.1, AnimationConfig::spring());
                },
                "Welcome, {user.name}!"
            }
        },
        _ => rsx! { div { "Loading..." } }
    }
}

Acknowledgment

Special thanks to Marc for creating the excellent dioxus-query library, which has been a significant inspiration for this project. Marc's work on dioxus-query has helped establish best practices for data management in the Dioxus ecosystem, and we encourage users to explore both libraries to find the best fit for their specific use case.

Contributing

Contributions are welcome! Please feel free to open an issue or submit a pull request.

License

This project is licensed under the MIT License.