Request interceptors intercept the whole request, and are called once for each request. They can provide additional endpoint interceptors, as well as modify the request, server endpoints, or the response.
The following request interceptors are provided by default (and if enabled, called in this order):
the metrics interceptor, which by default is disabled
a CORS interceptor (disabled by default)
RejectInterceptor, which specifies what should be done when decoding the request has failed for all interpreted endpoints. The default is to return a 405 (method not allowed), if there’s at least one decode failure on the method, and a “no-match” otherwise (which is handled in an intereprter-specific manner)
Request interceptors for two common scenarios can be created using the
Note, that for most server interpreters, the server endpoints passed to the request interceptor will be pre-filtered
FilterServerEndpoints, as a performance optimization (these will be only the endpoints for which the request
path might potentially decode successfully).
To enable, disable or configure an interceptor, you’ll need to modify the server options, using the
EndpointInterceptor allows intercepting the handling of a request by an endpoint, when either the endpoint’s inputs
have been decoded successfully, or when decoding has failed.
The following interceptors are used by default, and if enabled, called in this order:
unsupported media type interceptor
decode failure handler interceptor
Note that while the request will be passed top-to-bottom, handling of the result will be done in opposite order. E.g., if the result is a failed effect (an exception), it will first be logged by the logging interceptor, and only later passed to the exception interceptor.
customiseInterceptors on the options companion object, it is possible to customise the built-in interceptors. New
ones can be prepended to the interceptor stack using
.prependInterceptor, added before the decode failure interceptor
.addInterceptor, or appended using
.appendInterceptor. Customisation can include removing the interceptor
When implementing interceptors, it might be useful to take advantage of attributes, which can be attached both to
requests, as well as endpoint descriptions. Attributes are keyed using an
AttributeKey. Typically, each attribute
corresponds to a unique type, and the key instance for that type can be created using
AttributeKey[T]. The attribute
values then have to be of the given type