/
client_middleware.go
48 lines (41 loc) · 1.37 KB
/
client_middleware.go
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package requests
import "net/http"
const (
clientMiddlewareKey CtxKeyString = "__client_middleware_key"
)
// MiddlewareFunc middleware handler func
type MiddlewareFunc = func(c *Client, r *http.Request) (*Response, error)
// clientMiddleware is the plugin for http client request workflow management.
type clientMiddleware struct {
client *Client // http client.
handlers []MiddlewareFunc // mdl handlers.
handlerIndex int // current handler index.
response *Response // save resp.
err error // save err.
}
// Use adds one or more middleware handlers to client.
func (c *Client) Use(middlewares ...MiddlewareFunc) *Client {
c.middlewares = append(c.middlewares, middlewares...)
return c
}
// Next calls the next middleware.
// This should only be call in HandlerFunc.
func (c *Client) Next(req *http.Request) (*Response, error) {
if v := req.Context().Value(clientMiddlewareKey); v != nil {
if m, ok := v.(*clientMiddleware); ok {
return m.Next(req)
}
}
return c.callRequest(req)
}
// Next calls the next middleware handler.
func (m *clientMiddleware) Next(req *http.Request) (response *Response, err error) {
if m.err != nil {
return m.response, m.err
}
if m.handlerIndex < len(m.handlers) {
m.handlerIndex++
m.response, m.err = m.handlers[m.handlerIndex](m.client, req)
}
return m.response, m.err
}