response.go

Documentation: github.com/sassoftware/relic/server

     1  //
     2  // Copyright (c) SAS Institute Inc.
     3  //
     4  // Licensed under the Apache License, Version 2.0 (the "License");
     5  // you may not use this file except in compliance with the License.
     6  // You may obtain a copy of the License at
     7  //
     8  //     http://www.apache.org/licenses/LICENSE-2.0
     9  //
    10  // Unless required by applicable law or agreed to in writing, software
    11  // distributed under the License is distributed on an "AS IS" BASIS,
    12  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  // See the License for the specific language governing permissions and
    14  // limitations under the License.
    15  //
    16  
    17  package server
    18  
    19  import (
    20  	"encoding/json"
    21  	"fmt"
    22  	"net/http"
    23  )
    24  
    25  type Response interface {
    26  	Headers() map[string]string
    27  	Status() int
    28  	Bytes() []byte
    29  }
    30  
    31  type bytesResponse struct {
    32  	StatusCode  int
    33  	ContentType string
    34  	Body        []byte
    35  }
    36  
    37  func (r bytesResponse) Bytes() []byte {
    38  	return r.Body
    39  }
    40  
    41  func (r bytesResponse) Status() int {
    42  	return r.StatusCode
    43  }
    44  
    45  func (r bytesResponse) Headers() map[string]string {
    46  	return map[string]string{
    47  		"Content-Length": fmt.Sprintf("%d", len(r.Body)),
    48  		"Content-Type":   r.ContentType,
    49  	}
    50  }
    51  
    52  func BytesResponse(body []byte, contentType string) Response {
    53  	return &bytesResponse{
    54  		StatusCode:  http.StatusOK,
    55  		ContentType: contentType,
    56  		Body:        body,
    57  	}
    58  }
    59  
    60  func StringResponse(statusCode int, body string) Response {
    61  	return &bytesResponse{
    62  		StatusCode:  statusCode,
    63  		ContentType: "text/plain",
    64  		Body:        []byte(body + "\r\n"),
    65  	}
    66  }
    67  
    68  func ErrorResponse(statusCode int) Response {
    69  	return &bytesResponse{
    70  		StatusCode:  statusCode,
    71  		ContentType: "text/plain",
    72  		Body:        []byte(http.StatusText(statusCode) + "\r\n"),
    73  	}
    74  }
    75  
    76  var AccessDeniedResponse Response = &bytesResponse{
    77  	StatusCode:  http.StatusForbidden,
    78  	ContentType: "text/plain",
    79  	Body:        []byte("Access denied\r\n"),
    80  }
    81  
    82  func JSONResponse(data interface{}) (Response, error) {
    83  	blob, err := json.Marshal(data)
    84  	if err != nil {
    85  		return nil, err
    86  	}
    87  	return &bytesResponse{
    88  		StatusCode:  http.StatusOK,
    89  		ContentType: "application/json",
    90  		Body:        blob,
    91  	}, nil
    92  }
    93  
    94  func writeResponse(writer http.ResponseWriter, response Response) {
    95  	for k, v := range response.Headers() {
    96  		writer.Header().Set(k, v)
    97  	}
    98  	writer.WriteHeader(response.Status())
    99  	writer.Write(response.Bytes())
   100  }
   101
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