/
struct_load.go
88 lines (75 loc) · 2.09 KB
/
struct_load.go
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package adapters
import (
"fmt"
"github.com/AdikaStyle/go-df/backend"
"github.com/AdikaStyle/go-df/dataframe"
"github.com/AdikaStyle/go-df/types"
"reflect"
)
func LoadStructs(structsArray interface{}, tag string) dataframe.Dataframe {
structs := reflect.ValueOf(structsArray)
headers := analyzeStruct(structs.Index(0).Type(), tag)
be := backend.New(headers)
populateStructs(be, structs, tag)
return dataframe.New(be)
}
func populateStructs(be backend.Backend, structs reflect.Value, tag string) {
len := structs.Len()
for i := 0; i < len; i++ {
val := structs.Index(i)
be.AppendRow(structToRow(val, tag))
}
}
func structToRow(valOf reflect.Value, tag string) backend.Row {
row := make(backend.Row)
for i := 0; i < valOf.NumField(); i++ {
key := extractFieldName(valOf.Type().Field(i), tag)
kind := types.MatchKind(valOf.Field(i).Interface())
val := types.Convert(valOf.Field(i).Interface(), kind)
row[key] = val
}
return row
}
func analyzeStruct(tpe reflect.Type, tag string) backend.Headers {
var out backend.Headers
fieldsCount := tpe.NumField()
for i := 0; i < fieldsCount; i++ {
field := tpe.Field(i)
tagVal := extractFieldName(field, tag)
if tagVal == "-" {
continue
}
out = append(out, backend.Header{
Name: tagVal,
Kind: goTypeToKind(field.Type),
Visible: true,
})
}
return out
}
func extractFieldName(field reflect.StructField, tag string) string {
tagVal, found := field.Tag.Lookup(tag)
if !found {
tagVal = field.Name
}
return tagVal
}
func goTypeToKind(tpe reflect.Type) types.TypeKind {
if tpe.Name() == "Time" {
return types.KindDatetime
}
switch tpe.Kind() {
case reflect.Bool:
return types.KindBoolean
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
return types.KindInteger
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
return types.KindInteger
case reflect.Float32, reflect.Float64:
return types.KindDecimal
case reflect.String:
return types.KindString
default:
panic(fmt.Errorf("failed to convert go type: %d to dataframe type", tpe.Kind()))
}
}