github.com/OpsMx/go-app-base@v0.0.24/httputil/errors.go (about)

     1  // Copyright 2022 OpsMx, Inc
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // 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,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package httputil
    16  
    17  import (
    18  	"encoding/json"
    19  	"net/http"
    20  
    21  	"log"
    22  )
    23  
    24  // StatusCodeOK returns true if the error code provided is between
    25  // 200 and 2999, inclusive.
    26  func StatusCodeOK(statusCode int) bool {
    27  	return statusCode >= 200 && statusCode <= 299
    28  }
    29  
    30  // httpError defines a simple struct to return JSON formatted error
    31  // messages.
    32  type httpError struct {
    33  	Status string      `json:"status,omitempty" yaml:"status,omitempty"`
    34  	Code   int         `json:"code,omitempty" yaml:"code,omitempty"`
    35  	Error  interface{} `json:"error,omitempty" yaml:"error,omitempty"`
    36  }
    37  
    38  // SetError returns a JSON error message with a Status field set to 'error',
    39  // a 'code' set to the provided code, and the 'error' set to the provided
    40  // content.
    41  //
    42  // Prior to calling, nothing should be written to the writer, and afterwards
    43  // nothing should be written.
    44  //
    45  // The content-type will be set to application/json.
    46  func SetError(w http.ResponseWriter, statusCode int, message interface{}) {
    47  	w.Header().Set("content-type", "application/json")
    48  	w.WriteHeader(statusCode)
    49  	m := httpError{Status: "error", Code: statusCode, Error: message}
    50  	d, err := json.Marshal(m)
    51  	if err != nil {
    52  		log.Printf("marshalling error json: %v", err)
    53  	}
    54  	l, err := w.Write(d)
    55  	if l != len(d) {
    56  		log.Printf("writing error json: %d of %d bytes written", l, len(d))
    57  		return
    58  	}
    59  	if err != nil {
    60  		log.Printf("writing error json: %v", err)
    61  	}
    62  }