README
¶
CSV
Package CSV is a package to parse a full csv reader inside a slice structure. Allow to configure a decoder to transform directly csv entries into csv structure.
I had this specific need because i would to parse many csv files for differents type structure.
This package allow to configure dynamicly the structure builder to parse each entries files.
If you need an easy parser to decode csv file basicly, prefer use the csvutil package
Install
$> go get github.com/gofast-pkg/csv@latest
Usage
Examples are provided on the go doc reference
Contributing
❕ Use issues for everything
Read more informations with the CONTRIBUTING_GUIDE
For all changes, please update the CHANGELOG.txt file by replacing the existant content.
Thank you 🙏 👍
Made with contrib.rocks.
Licence
Documentation
¶
Overview ¶
Package csv allow to parse csv file line by line and transform each row in a data model. Expose a DecoderConfig to define custom behavior for each row.
Index ¶
Examples ¶
Constants ¶
const (
ExtensionFile = ".csv"
)
ExtensionFile for the csv file type.
Variables ¶
var ( ErrNilOBJ = errors.New("obj is nil") ErrNilReader = errors.New("io.reader is nil") ErrNilDecoder = errors.New("decoder is nil") ErrOBJDecode = errors.New("fails to decode into specific object") ErrToCreateNewInstance = errors.New("fails to create new obj instance") ErrToSaveNewInstance = errors.New("fails to save new obj instance") ErrToCheckWarning = errors.New("fails to check the unused fields") )
Errors supported by the csv operations.
var (
ErrInvalidConfigDecoder = errors.New("ConfigDecoder is invalid")
)
Errors supported by the decoder.
Functions ¶
This section is empty.
Types ¶
type CSV ¶
type CSV interface {
// DecodeWithDecoder parse the CSV file with a custom decoder.
// Decoder allows you to apply specific behavior to each line of the csv.
// (see: Decoder type and NewDecoder func)
DecodeWithDecoder(d Decoder) error
// Decode the csv file loaded into the obj instance.
// Each call to Decode read and process one line of the CSV file.
// Decode return a Warning object iterable like a map to check fields
// which are not used.
Decode(obj any) (Warning, error)
}
CSV interface creates a new interface ready to parse a csv file.
func New ¶
New create a new CSV reader from an io.Reader. Separator is the separator used in the CSV file.
Example ¶
package main
import (
"fmt"
"os"
"github.com/gofast-pkg/csv"
"github.com/stretchr/testify/assert"
)
const withValidCSVFile = "testdata/valid.csv"
func main() {
type Model struct {
Name string `csv:"name"`
Type string `csv:"type"`
MainColor string `csv:"main_color"`
Size string `csv:"size"`
}
reader, err := os.Open(withValidCSVFile)
if err != nil {
panic(err)
}
defer func() {
if err = reader.Close(); err != nil {
panic(err)
}
}()
csvReader, err := csv.New(reader, ';')
if err != nil {
panic(err)
}
exampleContextKey := "example-key"
list := []Model{}
cfg := csv.ConfigDecoder{
NewInstanceFunc: func(_ csv.Decoder) (any, error) { return &Model{}, nil },
SaveInstanceFunc: func(dec csv.Decoder, obj any) error {
// manipulate data in the decoder context
v, ok := dec.ContextGet(exampleContextKey)
if !ok {
return assert.AnError
}
if count, ok := v.(*int); ok {
(*count)++
dec.ContextSet(exampleContextKey, count)
}
if v, ok := obj.(*Model); ok {
list = append(list, *v)
return nil
}
return assert.AnError
},
WarningInstanceFunc: func(_ csv.Decoder, warn csv.Warning) error {
for k, v := range warn {
fmt.Printf("warning with key %s value %s\n", k, v)
}
return nil
},
}
decoder, err := csv.NewDecoder(cfg)
if err != nil {
panic(err)
}
// records some datas in the decoder context
count := int(0)
decoder.ContextSet(exampleContextKey, &count)
err = csvReader.DecodeWithDecoder(decoder)
if err != nil {
panic(err)
}
for _, v := range list {
fmt.Println(v)
}
fmt.Println(count)
}
Output: {Root Dog black big} {Toto Human blue small} 2
type ConfigDecoder ¶
type ConfigDecoder struct {
NewInstanceFunc func(Decoder) (any, error)
SaveInstanceFunc func(Decoder, any) error
WarningInstanceFunc func(Decoder, Warning) error
}
ConfigDecoder is the configuration to create a new decoder.
type Decoder ¶
type Decoder interface {
ContextSet(key string, value any)
ContextGet(key string) (value any, found bool)
// contains filtered or unexported methods
}
Decoder is the interface that wraps the basic methods to decode a csv file with a specific process for each line of the file.
func NewDecoder ¶
func NewDecoder(conf ConfigDecoder) (Decoder, error)
NewDecoder returns a new decoder with the specific configuration. If the configuration is not valid, the function returns an error of type ErrInvalidConfigDecoder.
Source Files
Directories