Documentation
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Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func BusinessErrorMiddleware ¶ added in v0.2.0
BusinessErrorMiddleware checks if a returned error is a business error and wraps it in a failer response if it is. Deprecated: Use FailerMiddleware instead.
func Chain ¶ added in v0.2.0
Chain composes a single middleware from a list. Compared to endpoint.Chain, this function accepts a variadic list.
Example ¶
annotate := func(pos string) endpoint.Middleware {
return func(e endpoint.Endpoint) endpoint.Endpoint {
return func(ctx context.Context, req interface{}) (response interface{}, err error) {
fmt.Println(pos + " pre")
response, err = e(ctx, req)
fmt.Println(pos + " post")
return
}
}
}
e := endpoint.Chain(
annotate("first"),
annotate("second"),
annotate("third"),
)(
func(context.Context, interface{}) (interface{}, error) {
fmt.Println("endpoint")
return nil, nil
},
)
if _, err := e(ctx, req); err != nil {
panic(err)
}
Output: first pre second pre third pre endpoint third post second post first post
func FailerMiddleware ¶ added in v0.4.0
func FailerMiddleware(matcher ErrorMatcher) endpoint.Middleware
FailerMiddleware checks if a returned error matches a predicate and wraps it in a failer response if it does.
Types ¶
type ErrorMatcher ¶ added in v0.4.0
type ErrorMatcher interface {
// MatchError evaluates the predicate for an error.
MatchError(err error) bool
}
ErrorMatcher is a predicate for errors. It can be used in middleware to decide whether to take action or not.
type ErrorMatcherFunc ¶ added in v0.4.0
ErrorMatcherFunc turns a plain function into an ErrorMatcher if it's definition matches the interface.
func (ErrorMatcherFunc) MatchError ¶ added in v0.4.0
func (fn ErrorMatcherFunc) MatchError(err error) bool
MatchError calls the underlying function to evaluate the predicate.
type Factory ¶
type Factory interface {
// NewEndpoint returns an endpoint wrapped with preconfigured middleware.
// It also accepts an operation name for per operation middleware (eg. logging or tracing middleware).
NewEndpoint(name string, e endpoint.Endpoint) endpoint.Endpoint
}
Factory returns an endpoint wrapped with preconfigured middleware.
func NewFactory ¶
func NewFactory(middlewareFactories ...MiddlewareFactory) Factory
NewFactory returns a new Factory.
type MiddlewareFactory ¶
type MiddlewareFactory func(name string) endpoint.Middleware
MiddlewareFactory creates a middleware per operation.
func Middleware ¶
func Middleware(middleware endpoint.Middleware) MiddlewareFactory
Middleware wraps singleton middleware and wraps them in a MiddlewareFactory.
Source Files