74 lines
1.6 KiB
Go
74 lines
1.6 KiB
Go
package main
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import (
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"net/http"
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"strconv"
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"github.com/aymerick/raymond"
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)
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// errorCatcher is a wrapper for http.ResponseWriter that
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// captures 4xx and 5xx status codes and handles them in
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// a custom manner
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type errorCatcher struct {
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req *http.Request
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res http.ResponseWriter
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errorTpl *raymond.Template
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notFoundTpl *raymond.Template
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handledError bool
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}
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func (ec *errorCatcher) Header() http.Header {
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return ec.res.Header()
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}
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func (ec *errorCatcher) Write(buf []byte) (int, error) {
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// if we have already sent a response, pretend that this was successful
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if ec.handledError {
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return len(buf), nil
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}
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return ec.res.Write(buf)
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}
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func (ec *errorCatcher) WriteHeader(statusCode int) {
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if ec.handledError {
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return
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}
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if statusCode == 404 {
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ctx := map[string]string{
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"path": ec.req.URL.Path,
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}
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page, err := ec.notFoundTpl.Exec(ctx)
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// if we don't have a page to write, return before
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// we toggle the flag so we fall back to the original
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// error page
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if err != nil {
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return
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}
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ec.res.Header().Add("content-type", "text/html")
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ec.res.WriteHeader(statusCode)
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ec.res.Write([]byte(page))
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ec.handledError = true
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return
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}
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if statusCode >= 400 && statusCode < 600 {
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ctx := map[string]string{
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"code": strconv.Itoa(statusCode),
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}
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page, err := ec.errorTpl.Exec(ctx)
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// if we don't have a page to write, return before
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// we toggle the flag so we fall back to the original
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// error page
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if err != nil {
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return
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}
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ec.res.Header().Add("content-type", "text/html")
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ec.res.WriteHeader(statusCode)
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ec.res.Write([]byte(page))
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ec.handledError = true
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return
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}
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ec.res.WriteHeader(statusCode)
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}
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