actix-web-lab

In-progress extractors and middleware for Actix Web.

What Is This Crate?

This crate serves as a preview and test ground for upcoming features and ideas for Actix Web's built in library of extractors, middleware and other utilities.

Any kind of feedback is welcome.

Complete Examples

See the examples folder for some complete examples of items in this crate.

Things To Know About This Crate

• It will never reach v1.0.
• Minimum Supported Rust Version (MSRV) is latest stable at the time of each release.
• Breaking changes will likely happen on most 0.x version bumps.
• Documentation might be limited for some items.
• Items that graduate to Actix Web crate will be marked deprecated here for a reasonable amount of time so you can migrate.
• Migrating will often be as easy as dropping the _lab suffix from imports when migrating.

Features

Feature Voting →

Responders

• Csv: efficient CSV streaming (docs)
• NdJson: efficient NDJSON streaming (docs)
• DisplayStream: efficient line-by-line Display streaming (docs)
• Html: (graduated 🎉) basic string wrapper that responds with HTML Content-Type (docs)
• Cbor: basic CBOR format wrapper with appropriate Content-Type (docs)
• MessagePack: basic MessagePack format wrapper with appropriate Content-Type (docs)
• Sse: semantic server-sent events (SSE) responder with a channel-like interface (docs)

Middleware

• from_fn: (graduated 🎉) use an async function as a middleware (docs)
• map_response: use an async function to modify the response (docs)
• map_response_body: use an async function to modify the response body (docs)
• RedirectHttps: middleware to redirect traffic to HTTPS if connection is insecure with optional HSTS (docs)
• RedirectToWww: middleware to redirect traffic to www. if not already there (docs)
• RedirectToNonWww: middleware to redirect traffic away from www. if it's present (docs)
• ConditionOption: conditional middleware helper (docs)
• ErrorHandlers: alternative error handler middleware with simpler interface (docs)
• NormalizePath: alternative path normalizing middleware with redirect option (docs)
• CatchPanic: catch panics in wrapped handlers and middleware, returning empty 500 responses (docs)
• PanicReporter: catch panics in wrapped handlers and middleware, returning empty 500 responses (docs)
• LoadShed: sheds load when the inner service isn't ready (docs)

Extractors

• LazyData: app data/state initialized on first use (docs)
• SwapData: app data/state that can be replaced at runtime (alternative to Data<RwLock<T>>) (docs)
• LocalData: app data/state that uses an Rc internally, avoiding atomic overhead (alternative to Data<RwLock<T>>) (docs)
• ThinData: (graduated 🎉) app data/state for cheaply-cloned types (docs)
• Json: simplified JSON extractor with const-generic payload limits and error paths (docs)
• deser_0_10::DeserJson: JSON extractor that uses deser v0.10 with const-generic payload limits and error paths (docs)
• Path: simplified path parameter extractor that supports destructuring (docs)
• Query: simplified query-string extractor that can also collect multi-value items (docs)
• RequestSignature: wraps an extractor and calculates a request signature alongside (docs)
• BodyLimit: wraps a body extractor and prevents DoS attacks by limiting payload size (docs)
• Bytes: simplified Bytes extractor with const-generic limits (docs)
• UrlEncodedForm: URL-encoded form extractor with const-generic payload size limit (docs)
• Host: Host information taken from either URL or Host header (docs)

Macros

• FromRequest: Derive macro to implement FromRequest on an aggregate struct of other extractors (docs)

Headers

• CacheControl: Cache-Control typed header with support for modern directives (docs)
• ClearSiteData: Clear-Site-Data typed header (docs)
• ContentLength: Content-Length typed header (docs)
• Forwarded: Proxy and original client info (docs)
• StrictTransportSecurity: Strict-Transport-Security (HSTS) configuration (docs)

Body Types

• channel: a simple channel-like body type with a sender side that can be used from another thread (docs)
• writer: a simple AsyncWrite body type (docs)

Services

• Redirect: (graduated 🎉) simple redirects (docs)
• spa: Easy Single-page Application (SPA) service (docs)

Route Guards

• Acceptable: (graduated 🎉) verifies that an Accept header is present and it contains a compatible MIME type (docs)

Test Utilities

• test_request: construct TestRequest using an HTTP-like DSL (docs)
• assert_response_matches: quickly write tests that check various parts of a ServiceResponse (docs)

Other Utilities

• fork_request_payload: effectively clone a request payload (docs)

Things To Know About This Crate

• It will never reach v1.0.
• Minimum Supported Rust Version (MSRV) is latest stable at the time of each release.
• Breaking changes will likely happen on most 0.x version bumps.
• Documentation might be limited for some items.
• Items that graduate to Actix Web crate will be marked deprecated here for a reasonable amount of time so you can migrate.
• Migrating will often be as easy as dropping the _lab suffix from imports.