101 lines
2.4 KiB
Go
101 lines
2.4 KiB
Go
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// Copyright 2016 Tim Shannon. All rights reserved.
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// Use of this source code is governed by the MIT license
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// that can be found in the LICENSE file.
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package main
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import (
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"encoding/json"
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"io"
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"io/ioutil"
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"log"
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"net/http"
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)
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const (
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statusSuccess = "success"
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statusError = "error"
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statusFail = "fail"
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)
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const maxJSONSize = 1 << 20 //10MB
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var errInputTooLarge = &Fail{
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Message: "Input size is too large, please check your input and try again",
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HTTPStatus: http.StatusRequestEntityTooLarge,
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}
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// JSend is the standard format for a response from townsourced
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type JSend struct {
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Status string `json:"status"`
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Data interface{} `json:"data,omitempty"`
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Message string `json:"message,omitempty"`
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Failures []error `json:"failures,omitempty"`
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More bool `json:"more,omitempty"` // more data exists for this request
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}
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//respondJsend marshalls the input into a json byte array
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// and writes it to the reponse with appropriate header
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func respondJsend(w http.ResponseWriter, response *JSend) {
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respondJsendCode(w, response, 0)
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}
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// respondJsendCode is the same as respondJSend, but lets you specify a status code
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func respondJsendCode(w http.ResponseWriter, response *JSend, statusCode int) {
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w.Header().Set("Cache-Control", "no-cache")
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w.Header().Set("Content-Type", "application/json")
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if len(response.Failures) > 0 && response.Message == "" {
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response.Message = "One or more item has failed. Check the individual failures for details."
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}
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result, err := json.MarshalIndent(response, "", " ")
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if err != nil {
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log.Printf("Error marshalling response: %s", err)
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result, _ = json.Marshal(&JSend{
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Status: statusError,
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Message: "An internal error occurred, and we'll look into it.",
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})
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}
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if statusCode <= 0 {
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switch response.Status {
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case statusFail:
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w.WriteHeader(http.StatusBadRequest)
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case statusError:
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w.WriteHeader(http.StatusInternalServerError)
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}
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//default is status 200
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} else {
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w.WriteHeader(statusCode)
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}
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_, err = w.Write(result)
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if err != nil {
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log.Printf("Error writing jsend response: %s", err)
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}
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}
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func parseInput(r *http.Request, result interface{}) error {
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lr := &io.LimitedReader{R: r.Body, N: maxJSONSize + 1}
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buff, err := ioutil.ReadAll(lr)
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if err != nil {
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return err
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}
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if lr.N == 0 {
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return errInputTooLarge
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}
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if len(buff) == 0 {
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return nil
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}
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err = json.Unmarshal(buff, result)
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if err != nil {
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return err
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}
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return nil
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}
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