feat: add initial support for custom entry unmarshaler

Author: cpuschma

v3/search.go

@@ -324,6 +324,35 @@ func (e *Entry) Unmarshal(i interface{}) (err error) {
 	return
 }
 
+func (e *Entry) UnmarshalFunc(i interface{},
+	fn func(entry *Entry, fieldType reflect.StructField, fieldValue reflect.Value) error) error {
+	// Make sure it's a ptr
+	if vo := reflect.ValueOf(i).Kind(); vo != reflect.Ptr {
+		return fmt.Errorf("ldap: cannot use %s, expected pointer to a struct", vo)
+	}
+
+	sv, st := reflect.ValueOf(i).Elem(), reflect.TypeOf(i).Elem()
+	// Make sure it's pointing to a struct
+	if sv.Kind() != reflect.Struct {
+		return fmt.Errorf("ldap: expected pointer to a struct, got %s", sv.Kind())
+	}
+
+	for n := 0; n < st.NumField(); n++ {
+		fv, ft := sv.Field(n), st.Field(n)
+
+		// skip unexported fields
+		if ft.PkgPath != "" {
+			continue
+		}
+
+		if err := fn(e, ft, fv); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
 // NewEntryAttribute returns a new EntryAttribute with the desired key-value pair
 func NewEntryAttribute(name string, values []string) *EntryAttribute {
 	var bytes [][]byte

v3/search_unmarshal_test.go

@@ -0,0 +1,67 @@
+package ldap
+
+import (
+	"fmt"
+	"reflect"
+	"testing"
+)
+
+func customUnmarshalFunc(entry *Entry, fieldType reflect.StructField, fieldValue reflect.Value) error {
+	tagData, ok := fieldType.Tag.Lookup("custom_tag")
+	if !ok {
+		return nil
+	}
+
+	value := entry.GetAttributeValue(tagData)
+	// log.Printf("Marshaling field %s with tag %s and value '%s'", fieldType.Name, tagData, value)
+	fieldValue.SetString(value)
+	return nil
+}
+
+func TestEntry_UnmarshalFunc(t *testing.T) {
+	conn, err := DialURL(ldapServer)
+	if err != nil {
+		t.Fatalf("Failed to connect: %s\n", err)
+	}
+	defer conn.Close()
+
+	searchResult, err := conn.Search(&SearchRequest{
+		BaseDN:     baseDN,
+		Scope:      ScopeWholeSubtree,
+		Filter:     "(cn=cis-fac)",
+		Attributes: []string{"cn", "objectClass"},
+	})
+	if err != nil {
+		t.Fatalf("Failed to search: %s\n", err)
+	}
+
+	type user struct {
+		ObjectClass string `custom_tag:"objectClass"`
+		CN          string `custom_tag:"cn"`
+	}
+
+	t.Run("success", func(t *testing.T) {
+		for _, entry := range searchResult.Entries {
+			var u user
+			if err := entry.UnmarshalFunc(&u, customUnmarshalFunc); err != nil {
+				t.Errorf("Failed to unmarshal entry: %s\n", err)
+			}
+
+			if u.CN != entry.GetAttributeValue("cn") {
+				t.Errorf("UnmarshalFunc did not set the field correctly. Expected: %s, got: %s", entry.GetAttributeValue("cn"), u.CN)
+			}
+		}
+	})
+
+	t.Run("error", func(t *testing.T) {
+		for _, entry := range searchResult.Entries {
+			var u user
+			err := entry.UnmarshalFunc(&u, func(entry *Entry, fieldType reflect.StructField, fieldValue reflect.Value) error {
+				return fmt.Errorf("error from custom unmarshal func on field: %s", fieldType.Name)
+			})
+			if err == nil {
+				t.Errorf("UnmarshalFunc should have returned an error")
+			}
+		}
+	})
+}