Added arrays to XMLProvider types for faster iteration

providers/xmlprovider/helpers.go

@@ -0,0 +1,32 @@
+package xmlprovider
+
+import (
+	"encoding/xml"
+	"io"
+	"os"
+
+	"github.com/Theodor-Springmann-Stiftung/kgpz_web/helpers/logging"
+)
+
+func UnmarshalFile[T any](filename string, data T) error {
+	xmlFile, err := os.Open(filename)
+	if err != nil {
+		logging.Error(err, "Could not open file: "+filename)
+		return err
+	}
+	defer xmlFile.Close()
+
+	logging.Info("Deserialization: " + filename)
+	byteValue, err := io.ReadAll(xmlFile)
+	if err != nil {
+		logging.Error(err, "Could not read file: "+filename)
+		return err
+	}
+	err = xml.Unmarshal(byteValue, &data)
+
+	if err != nil {
+		logging.Error(err, "Could not unmarshal file: "+filename)
+		return err
+	}
+	return nil
+}