GoLang - Persist using ISO-8859-1 charset

database, go, iso-8859-1, mysql, utf-8

Solution

package charset

import "code.google.com/p/go-charset/charset" 

func NewWriter

func NewWriter(charset string, w io.Writer) (io.WriteCloser, error)

`NewWriter` returns a new `WriteCloser` writing to `w`. It converts writes of UTF-8 text into writes on `w` of text in the named character set. The `Close` is necessary to flush any remaining partially translated characters to the output.

I would follow the instructions: "The `Close` is necessary to flush any remaining partially translated characters to the output." For example,

package main

import (
    "bytes"
    "code.google.com/p/go-charset/charset"
    _ "code.google.com/p/go-charset/data"
    "fmt"
    "io/ioutil"
    "strings"
)

func toISO88591(utf8 string) (string, error) {
    buf := new(bytes.Buffer)
    w, err := charset.NewWriter("latin1", buf)
    if err != nil {
        return "", err
    }
    fmt.Fprintf(w, utf8)
    w.Close()
    return buf.String(), nil
}

func fromISO88591(iso88591 string) (string, error) {
    r, err := charset.NewReader("latin1", strings.NewReader(iso88591))
    if err != nil {
        return "", err
    }
    buf, err := ioutil.ReadAll(r)
    if err != nil {
        return "", err
    }
    return string(buf), nil
}

func main() {
    utfi := "£5 for Peppé"
    fmt.Printf("%q\n", utfi)
    iso, err := toISO88591(utfi)
    if err != nil {
        fmt.Println(err)
    }
    fmt.Printf("%q\n", iso)
    utfo, err := fromISO88591(iso)
    if err != nil {
        fmt.Println(err)
    }
    fmt.Printf("%q\n", utfo)
    fmt.Println(utfi == utfo)
}

Output:

"£5 for Peppé"
"\xa35 for Pepp\xe9"
"£5 for Peppé"
true

Problem

I'm developing a project where we need to persist our information in a legacy database that has ISO-8859-1 tables. So before writing something to the database I need to convert it from UTF-8 to ISO-8859-1, and every time I retrieve it from the database, I need to convert it back to UTF-8. I was trying to use the library code.google.com/p/go-charset/ as the following for each text field that I need to persist. ``` import ( "bytes" "code.google.com/p/go-charset/charset" _ "code.google.com/p/go-charset/data" "fmt" "io/ioutil" "strings" ) func toISO88591(utf8 string) string { buf := new(bytes.Buffer) w, err := charset.NewWriter("latin1", buf) if err != nil { panic(err) } defer w.Close() fmt.Fprintf(w, utf8) return buf.String() } func fromISO88591(iso88591 string) string { r, err := charset.NewReader("latin1", strings.NewReader(iso88591)) if err != nil { panic(err) } buf, err := ioutil.ReadAll(r) if err != nil { panic(err) } return string(buf) } ``` The problem is that the data is still persisted in UTF-8 even if I use the function toISO88591. I am doing something wrong in this conversion? My database is a MySQL, and I'm using the github.com/go-sql-driver/mysql driver with the following connection parameters: ``` <user>:<password>@tcp(<host>:<port>)/<database>?collation=latin1_general_ci ``` Best regards!

Original source