75 lines
2.1 KiB
Go
75 lines
2.1 KiB
Go
package httpx
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import (
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"encoding/json"
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"errors"
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"net/http"
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)
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// ErrInterceptor intercepts errors and directly returns specific responses for them
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type ErrInterceptor struct {
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Errors map[error]Response
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Fallback Response
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}
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// Intercept attempts to intercept the given error.
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// When err is nil, does nothing.
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//
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// When err is not nil, first attempts to find a static response in errors and respond with that.
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// Otherwise it returns the Fallback response.
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// intercepted indicates if some response was sent.
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func (ei ErrInterceptor) Intercept(w http.ResponseWriter, r *http.Request, err error) (intercepted bool) {
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if err == nil {
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return false
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}
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res, ok := ei.Errors[err]
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if !ok {
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res = ei.Fallback
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}
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res.ServerHTTP(w, r)
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return true
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}
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// StatusInterceptor creates a new ErrInterceptor handling default responses.
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// If body returns err != nil, StatusInterceptor calls panic().
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func StatusInterceptor(contentType string, body func(code int, text string) ([]byte, error)) ErrInterceptor {
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makeResponse := func(code int) (res Response) {
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var err error
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res.Body, err = body(code, http.StatusText(code))
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if err != nil {
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panic("StatusInterceptor: err != nil")
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}
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res.ContentType = contentType
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res.StatusCode = code
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return
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}
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return ErrInterceptor{
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Errors: map[error]Response{
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ErrNotFound: makeResponse(http.StatusNotFound),
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ErrForbidden: makeResponse(http.StatusForbidden),
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},
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Fallback: makeResponse(http.StatusInternalServerError),
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}
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}
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// Common errors accepted by all httpx handlers
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var (
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ErrNotFound = errors.New("httpx: Not Found")
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ErrForbidden = errors.New("httpx: Forbidden")
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)
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var (
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textInterceptor = StatusInterceptor("text/plain", func(code int, text string) ([]byte, error) {
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return []byte(text), nil
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})
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jsonInterceptor = StatusInterceptor("application/json", func(code int, text string) ([]byte, error) {
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return json.Marshal(map[string]any{"status": text, "code": code})
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})
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htmlInterceptor = StatusInterceptor("text/html", func(code int, text string) ([]byte, error) {
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return []byte(`<!DOCTYPE HTML><title>` + text + `</title>` + text), nil
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})
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)
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