geziyor/exporter/csv.go
2019-06-15 22:35:51 +03:00

65 lines
1.2 KiB
Go

package exporter
import (
"encoding/csv"
"fmt"
"log"
"os"
"reflect"
"sync"
)
// CSVExporter exports response data as CSV streaming file
type CSVExporter struct {
FileName string
once sync.Once
writer *csv.Writer
}
// Export exports response data as CSV streaming file
func (e *CSVExporter) Export(exports chan interface{}) {
// Default filename
if e.FileName == "" {
e.FileName = "out.csv"
}
// Create file
e.once.Do(func() {
newFile, err := os.OpenFile(e.FileName, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0666)
if err != nil {
fmt.Fprintf(os.Stderr, "output file creation error: %v", err)
return
}
e.writer = csv.NewWriter(newFile)
})
// Export data as responses came
for res := range exports {
var values []string
// Detect type and extract CSV values
val := reflect.ValueOf(res)
switch val.Kind() {
case reflect.Slice:
for i := 0; i < val.Len(); i++ {
values = append(values, fmt.Sprint(val.Index(i)))
}
//case reflect.Map:
// iter := val.MapRange()
// for iter.Next() {
// values = append(values, fmt.Sprint(iter.Value()))
// }
}
// Write to file
if err := e.writer.Write(values); err != nil {
log.Printf("CSV writing error on exporter: %v\n", err)
}
}
e.writer.Flush()
}