github.com/line/line-bot-sdk-go/v7@v7.21.0/linebot/httphandler/httphandler.go (about)

     1  // Copyright 2016 LINE Corporation
     2  //
     3  // LINE Corporation licenses this file to you under the Apache License,
     4  // version 2.0 (the "License"); you may not use this file except in compliance
     5  // with the License. You may obtain a copy of the License at:
     6  //
     7  //   http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
    11  // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
    12  // License for the specific language governing permissions and limitations
    13  // under the License.
    14  
    15  package httphandler
    16  
    17  import (
    18  	"errors"
    19  	"net/http"
    20  
    21  	"github.com/line/line-bot-sdk-go/v7/linebot"
    22  )
    23  
    24  // EventsHandlerFunc type
    25  type EventsHandlerFunc func([]*linebot.Event, *http.Request)
    26  
    27  // ErrorHandlerFunc type
    28  type ErrorHandlerFunc func(error, *http.Request)
    29  
    30  // WebhookHandler type
    31  type WebhookHandler struct {
    32  	channelSecret string
    33  	channelToken  string
    34  
    35  	handleEvents EventsHandlerFunc
    36  	handleError  ErrorHandlerFunc
    37  }
    38  
    39  // New returns a new WebhookHandler instance.
    40  func New(channelSecret, channelToken string) (*WebhookHandler, error) {
    41  	if channelSecret == "" {
    42  		return nil, errors.New("missing channel secret")
    43  	}
    44  	if channelToken == "" {
    45  		return nil, errors.New("missing channel access token")
    46  	}
    47  	h := &WebhookHandler{
    48  		channelSecret: channelSecret,
    49  		channelToken:  channelToken,
    50  	}
    51  	return h, nil
    52  }
    53  
    54  // HandleEvents method
    55  func (wh *WebhookHandler) HandleEvents(f EventsHandlerFunc) {
    56  	wh.handleEvents = f
    57  }
    58  
    59  // HandleError method
    60  func (wh *WebhookHandler) HandleError(f ErrorHandlerFunc) {
    61  	wh.handleError = f
    62  }
    63  
    64  // NewClient method
    65  func (wh *WebhookHandler) NewClient(options ...linebot.ClientOption) (*linebot.Client, error) {
    66  	return linebot.New(wh.channelSecret, wh.channelToken, options...)
    67  }
    68  
    69  func (wh *WebhookHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
    70  	events, err := linebot.ParseRequest(wh.channelSecret, r)
    71  	if err != nil {
    72  		if wh.handleError != nil {
    73  			wh.handleError(err, r)
    74  		}
    75  		if err == linebot.ErrInvalidSignature {
    76  			w.WriteHeader(400)
    77  		} else {
    78  			w.WriteHeader(500)
    79  		}
    80  		return
    81  	}
    82  	wh.handleEvents(events, r)
    83  }