|
- // Copyright 2015 Google Inc. All rights reserved.
- //
- // Licensed under the Apache License, Version 2.0 (the "License");
- // you may not use this file except in compliance with the License.
- // You may obtain a copy of the License at
- //
- // http://www.apache.org/licenses/LICENSE-2.0
- //
- // Unless required by applicable law or agreed to in writing, software
- // distributed under the License is distributed on an "AS IS" BASIS,
- // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- // See the License for the specific language governing permissions and
- // limitations under the License.
-
- // Package stash provides a modifier that stores the request URL in a
- // specified header.
- package stash
-
- import (
- "encoding/json"
- "fmt"
- "net/http"
-
- "github.com/google/martian/parse"
- )
-
- func init() {
- parse.Register("stash.Modifier", modifierFromJSON)
- }
-
- // Modifier adds a header to the request containing the current state of the URL.
- // The header will be named with the value stored in headerName.
- // There will be no validation done on this header name.
- type Modifier struct {
- headerName string
- }
-
- type modifierJSON struct {
- HeaderName string `json:"headerName"`
- Scope []parse.ModifierType `json:"scope"`
- }
-
- // NewModifier returns a RequestModifier that write the current URL into a header.
- func NewModifier(headerName string) *Modifier {
- return &Modifier{headerName: headerName}
- }
-
- // ModifyRequest writes the current URL into a header.
- func (m *Modifier) ModifyRequest(req *http.Request) error {
- req.Header.Set(m.headerName, req.URL.String())
- return nil
- }
-
- // ModifyResponse writes the same header written in the request into the response.
- func (m *Modifier) ModifyResponse(res *http.Response) error {
- res.Header.Set(m.headerName, res.Request.Header.Get(m.headerName))
- return nil
- }
-
- func modifierFromJSON(b []byte) (*parse.Result, error) {
- // If you would like the saved state of the URL to be written in the response you must specify
- // this modifier's scope as both request and response.
- msg := &modifierJSON{}
- if err := json.Unmarshal(b, msg); err != nil {
- return nil, err
- }
-
- mod := NewModifier(msg.HeaderName)
- r, err := parse.NewResult(mod, msg.Scope)
- if err != nil {
- return nil, err
- }
-
- if r.ResponseModifier() != nil && r.RequestModifier() == nil {
- return nil, fmt.Errorf("to write header on a response, specify scope as both request and response")
- }
-
- return r, nil
- }
|