photoprism/internal/entity/entity_values.go

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package entity
import (
"fmt"
"reflect"
)
// Values is a shortcut for map[string]interface{}
type Values map[string]interface{}
// ModelValues extracts Values from an entity model.
func ModelValues(m interface{}, keyNames ...string) (result Values, keys []interface{}, err error) {
isKey := func(name string) bool {
for _, s := range keyNames {
if name == s {
return true
}
}
return false
}
r := reflect.ValueOf(m)
if r.Kind() != reflect.Pointer {
return result, keys, fmt.Errorf("model interface expected")
}
values := r.Elem()
if kind := values.Kind(); kind != reflect.Struct {
return result, keys, fmt.Errorf("model expected")
}
t := values.Type()
num := t.NumField()
keys = make([]interface{}, 0, len(keyNames))
result = make(map[string]interface{}, num)
// Add exported fields to result.
for i := 0; i < num; i++ {
field := t.Field(i)
// Skip non-exported fields.
if !field.IsExported() {
continue
}
fieldName := field.Name
// Skip timestamps.
if fieldName == "" || fieldName == "UpdatedAt" || fieldName == "CreatedAt" {
continue
}
v := values.Field(i)
switch v.Kind() {
case reflect.Slice, reflect.Chan, reflect.Func, reflect.Map, reflect.UnsafePointer:
continue
case reflect.Struct:
if v.IsZero() {
continue
}
}
// Skip read-only fields.
if !v.CanSet() {
continue
}
// Skip keys.
if isKey(fieldName) {
if !v.IsZero() {
keys = append(keys, v.Interface())
}
continue
}
// Add value to result.
result[fieldName] = v.Interface()
}
if len(result) == 0 {
return result, keys, fmt.Errorf("no values")
}
return result, keys, nil
}