HTTP Router

Simple general purpose HTTP path based request router. Requires a compiler with C++20 support. No assumption is made on the type of framework being used. We have used it mainly with nghttp2

• Supports static and parametrised URI paths.

• Parameters (slugs) are represented using curly brace enclosed name {param}.

  • Curly brace form was chosen in favour of :param for sorting purpose.

  • Sorting with { implies use of non-ascii characters in path will have inconsistent behaviour.

• Wildcard path pattern is supported.

  • Only a single wildcard (*) as the last component of the URI path is supported.

  • Parameters (slugs) are supported in the same URI path (/device/sensor/id/{id}/*).

  • Internally the wildcard character * is replaced by ~ for sorting purpose.

  • As a consequence of sorting, it is possible to configure more specific URI wildcard paths in combination with wildcard paths at the base level. Example: /device/sensor/* and /device/sensor/id/*.

• Templated on the Response type and an input Request. Optionally specify the type of Map container to use to hold the parsed path parameters. Defaults to boost::container::flat_map if boost is found, or to std::map. The type specified must be interface compatible with std::map. The key and value must be either std::string_view or std::string.

• Function based routing. Successful matches are routed to the specified handler callback function.

  • Parameters are returned as a map. The type of map is determined via the optional third template parameter.

  • Callback function has signature Response( Request, MapType<String, String>&& ) where MapType is either boost::container::flat_map or std::map (if using defaults, or the container you specify) and String is std::string_view (if using defaults) or std::string if you specify. See string.cpp test for sample of specifying your preferred container and std::string as the type in the container.

  • The MapType will hold the parsed parameter->value pairs.

  • The path part matching the wildcard (for wildcard paths) is added to the MapType as _wildcard_ key. Keep this in mind when naming path parameters for wildcard paths.