Typesafe, compositional routing and reverse routing for Kotlin web apps and HTTP microservices.
Krouton provides a routing API for HTTP4K, but the core abstractions can be used with any web server library.
Type safe routing and reverse routing.
No reflection, annotations or classpath scanning.
Explicit, type-checked flow of data and control, instead of "spooky action at a distance" via reflection, annotations, classpath scanning, passing data in context maps or synthetic HTTP headers, or control flow via exceptions.
Separate code that routes and handles requests from definitions of URLs
- URLs defined by constants (immutable objects)
- Routing policy defined by operations on those constants
- Routing done by functions/closures/objects that connect Krouton's routing policy API to a web server library.
Compositional: routes are composed from primitive parts and composition operators. User-defined routes can be used in exactly the same way as the predefined primitives.
Mandatory aspects of a resource locator go in the path
Query parameters are optional and are interpreted by the resource.
- Parsing:
UrlScheme<T>.parse(String) -> T? - Reverse Routing:
UrlScheme<T>.path(T) -> String - Reporting:
UrlScheme<T>.monitoredPath(T)-> String
- Append:
UrlScheme<T> + UrlScheme<U> -> UrlScheme<Tuple2<T,U>>+operator supports appending paths for scalars and tuples, forming paths for tuples with up to five elementsUrlScheme<Unit> + UrlScheme<T> -> UrlScheme<T>UrlScheme<T> + UrlScheme<Unit> -> UrlScheme<T>
- Append fixed path element:
UrlScheme<T> + String -> UrlScheme<T> - Restrict:
UrlScheme<T> where ((T)->Boolean) -> UrlScheme<T> - Project:
UrlScheme<T> asA Projection<T,U> -> UrlScheme<U>
The version number is {mental}.{major}.{minor}.{patch}. The last three digits are treated as a semantic version number. The first digit is incremented if there is a significant change in the mental model underpinning the library. A major version of zero always signifies a pre-release version, irrespective of the value of the first digit. The API of pre-release versions may go through significant changes in response to user feedback before the release of version x.1.0.0.