mirror of https://github.com/jlelse/GoBlog
84 lines
1.9 KiB
Go
84 lines
1.9 KiB
Go
package main
|
|
|
|
import (
|
|
"database/sql"
|
|
"errors"
|
|
"net/http"
|
|
"strings"
|
|
)
|
|
|
|
var errRedirectNotFound = errors.New("redirect not found")
|
|
|
|
func serveRedirect(w http.ResponseWriter, r *http.Request) {
|
|
redirect, err := getRedirect(r.URL.Path)
|
|
if err == errRedirectNotFound {
|
|
serve404(w, r)
|
|
return
|
|
} else if err != nil {
|
|
http.Error(w, err.Error(), http.StatusInternalServerError)
|
|
return
|
|
}
|
|
// Send redirect
|
|
w.Header().Set("Location", redirect)
|
|
render(w, templateRedirect, &renderData{
|
|
Data: redirect,
|
|
})
|
|
w.WriteHeader(http.StatusFound)
|
|
}
|
|
|
|
func getRedirect(fromPath string) (string, error) {
|
|
var toPath string
|
|
row := appDb.QueryRow("with recursive f (i, fp, tp) as (select 1, fromPath, toPath from redirects where fromPath = ? union all select f.i + 1, r.fromPath, r.toPath from redirects as r join f on f.tp = r.fromPath) select tp from f order by i desc limit 1", fromPath)
|
|
err := row.Scan(&toPath)
|
|
if err == sql.ErrNoRows {
|
|
return "", errRedirectNotFound
|
|
} else if err != nil {
|
|
return "", err
|
|
}
|
|
return toPath, nil
|
|
}
|
|
|
|
func allRedirectPaths() ([]string, error) {
|
|
var redirectPaths []string
|
|
rows, err := appDb.Query("select fromPath from redirects")
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
for rows.Next() {
|
|
var path string
|
|
_ = rows.Scan(&path)
|
|
redirectPaths = append(redirectPaths, path)
|
|
}
|
|
return redirectPaths, nil
|
|
}
|
|
|
|
func createOrReplaceRedirect(from, to string) error {
|
|
if from == "" || to == "" {
|
|
return errors.New("empty path")
|
|
}
|
|
if from == to {
|
|
// Don't need a redirect
|
|
return nil
|
|
}
|
|
from = strings.TrimSuffix(from, "/")
|
|
startWritingToDb()
|
|
tx, err := appDb.Begin()
|
|
if err != nil {
|
|
finishWritingToDb()
|
|
return err
|
|
}
|
|
_, err = tx.Exec("insert or replace into redirects (fromPath, toPath) values (?, ?)", from, to)
|
|
if err != nil {
|
|
_ = tx.Rollback()
|
|
finishWritingToDb()
|
|
return err
|
|
}
|
|
err = tx.Commit()
|
|
if err != nil {
|
|
finishWritingToDb()
|
|
return err
|
|
}
|
|
finishWritingToDb()
|
|
return reloadRouter()
|
|
}
|