Viewmodels - Building blocks

Viewmodels.js

var TextInput = function (validationOptions) {
  if (!this instanceof TextInput) {
    return new TextInput(validationOptions);
  }

  validationOptions = validationOptions || {
    rules: {},
    messages: {}
  };

  var my = {
    emptyValue: '',
    validationOptions: validationOptions,
    validationMethods: [validation.methods.required, validation.methods.minLength, validation.methods.maxLength]
  }, self = new ValueInputObject(my);

  return self;
};

var NumericInput = function (validationOptions) {
  if (!this instanceof NumericInput) {
    return new NumericInput(validationOptions);
  }

  validationOptions = validationOptions || {
    rules: {},
    messages: {}
  };
  validationOptions.rules.number = true;

  var my = {
    emptyValue: '',
    validationOptions: validationOptions,
    validationMethods: [validation.methods.required, validation.methods.number, validation.methods.min, validation.methods.max]
  }, self = new ValueInputObject(my);

  return self;
};

var ValueInputObject = function (my) {
  if (!this instanceof ValueInputObject) {
    return new ValueInputObject(my);
  }

  var self = ValidatableExtension(
    PausableSubscriberExtension(
      DisposableExtension(
        FocusExtension(
          EnableExtension(
            VisibleExtension(
              this)))))),
    baseValue;

  my = my || {};
  my.emptyValue = my.emptyValue !== undefined ? my.emptyValue : null;
  my.validationOptions = my.validationOptions || {
    rules: {},
    messages: {}
  };
  my.validationMethods = my.validationMethods || [];
  baseValue = my.emptyValue;

  self.Value = ko.observable(my.emptyValue);

  self.validate = function () {
    var value = ko.utils.unwrapObservable(self.Value);
    var result = validation.validate(value, my.validationMethods, my.validationOptions);
    self.IsValid(result.isValid);
    self.ValidationMessage(result.isValid ? '' : result.messages[0]);
    return result.isValid;
  };

  self.invalidate = function(message) {
    self.IsValid(false);
    self.ValidationMessage(message);
  };

  self.bind = function (event, callback) {
    if (event === 'ValueChanged') {
      self.addSubscription(self.Value.subscribe(self.interceptSubscriber(function (value) {
        callback(value);
      })));
    }
  };

  self.clear = function () {
    self.Value(my.emptyValue);
    self.clearValidation();
  };

  self.reset = function () {
    self.Value(baseValue);
    self.clearValidation();
  };

  self.isChanged = function () {
    return ko.utils.unwrapObservable(self.Value) !== baseValue;
  };

  self.getValue = function () {
    return ko.utils.unwrapObservable(self.Value);
  };

  self.setValue = function (value) {
    baseValue = value;
    self.Value(value);
  };
  return self;
};