Adds steps logic for the register form.

addons/godot-form-validator/validators/validator.gd

@@ -0,0 +1,37 @@
+@tool
+extends Resource
+class_name Validator
+
+@export var validation_order: int = 1
+@export var validation_method: Validation.Method = Validation.Method.BATCH
+@export var skip_validation: bool = false
+@export var rules: Array[ValidatorRule] = []
+
+var _messages: PackedStringArray = PackedStringArray()
+
+
+func get_value(control: Control):
+	return null
+
+
+func is_type(node) -> bool:
+	return node is Control
+
+
+func get_messages() -> PackedStringArray:
+	return _messages
+
+
+func validate(control: Control) -> bool:
+	_messages.clear()
+	var valid = true
+	for rule in rules:
+		var result = rule.apply(control, get_value(control))
+		if not result.passed:
+			_messages.append(result.message)
+		valid = valid and result.passed
+		if not valid:
+			# Not BATCH, exit early.
+			if validation_method != Validation.Method.BATCH:
+				return valid
+	return valid