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133 lines
3.0 KiB
Go

package xlsx
import (
"errors"
"reflect"
"strconv"
"time"
)
var (
errNilInterface = errors.New("nil pointer is not a valid argument")
errNotStructPointer = errors.New("argument must be a pointer to struct")
errInvalidTag = errors.New(`invalid tag: must have the format xlsx:idx`)
)
//XLSXUnmarshaler is the interface implemented for types that can unmarshal a Row
//as a representation of themselves.
type XLSXUnmarshaler interface {
Unmarshal(*Row) error
}
//ReadStruct reads a struct from r to ptr. Accepts a ptr
//to struct. This code expects a tag xlsx:"N", where N is the index
//of the cell to be used. Basic types like int,string,float64 and bool
//are supported
func (r *Row) ReadStruct(ptr interface{}) error {
if ptr == nil {
return errNilInterface
}
//check if the type implements XLSXUnmarshaler. If so,
//just let it do the work.
unmarshaller, ok := ptr.(XLSXUnmarshaler)
if ok {
return unmarshaller.Unmarshal(r)
}
v := reflect.ValueOf(ptr)
if v.Kind() != reflect.Ptr {
return errNotStructPointer
}
v = v.Elem()
if v.Kind() != reflect.Struct {
return errNotStructPointer
}
n := v.NumField()
for i := 0; i < n; i++ {
field := v.Type().Field(i)
idx := field.Tag.Get("xlsx")
//do a recursive check for the field if it is a struct or a pointer
//even if it doesn't have a tag
//ignore if it has a - or empty tag
isTime := false
switch {
case idx == "-":
continue
case field.Type.Kind() == reflect.Ptr || field.Type.Kind() == reflect.Struct:
var structPtr interface{}
if !v.Field(i).CanSet() {
continue
}
if field.Type.Kind() == reflect.Struct {
structPtr = v.Field(i).Addr().Interface()
} else {
structPtr = v.Field(i).Interface()
}
//check if the container is a time.Time
_, isTime = structPtr.(*time.Time)
if isTime {
break
}
err := r.ReadStruct(structPtr)
if err != nil {
return err
}
continue
case len(idx) == 0:
continue
}
pos, err := strconv.Atoi(idx)
if err != nil {
return errInvalidTag
}
//check if desired position is not out of bounds
if pos > len(r.Cells)-1 {
continue
}
cell := r.Cells[pos]
fieldV := v.Field(i)
//continue if the field is not settable
if !fieldV.CanSet() {
continue
}
if isTime {
t, err := cell.GetTime(false)
if err != nil {
return err
}
if field.Type.Kind() == reflect.Ptr {
fieldV.Set(reflect.ValueOf(&t))
} else {
fieldV.Set(reflect.ValueOf(t))
}
continue
}
switch field.Type.Kind() {
case reflect.String:
value, err := cell.FormattedValue()
if err != nil {
return err
}
fieldV.SetString(value)
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
value, err := cell.Int64()
if err != nil {
return err
}
fieldV.SetInt(value)
case reflect.Float64:
value, err := cell.Float()
if err != nil {
return err
}
fieldV.SetFloat(value)
case reflect.Bool:
value := cell.Bool()
fieldV.SetBool(value)
}
}
value := v.Interface()
ptr = &value
return nil
}