Implementing validation rules

• Dynamic validation
• Defining custom validation rules
• Defining AJAX validation rules

Dynamic validation

To implement dynamic validation, define the validation as a function that returns validation rules.

  /* dataentry schema */
  schema: {
    propertyOne: {
      //This validation is dynamic
      validation: function () {
        //the function is called in the context of the scope (Angular); or model (Knockout); or form element (basic plugin usage)
        var rules = [];
        if (someCondition)
          return ["required"];
        //otherwise:
        return ["none"];
      }
    },
    propertyTwo: {
      //This validation is static
      validation: ["required"]
    }
  }

Defining a custom validation rule.

To define a custom validation rule, the $.Forms.Validation.Rules object must be extended:

  //custom rule definition: add a property to the $.Forms.Validation.Rules object
  $.Forms.Validation.Rules.myCustomRule = {

    fn: function (field, value, forced) {
      if (!value) return true;//return true if the value is empty, because this validation rule is not checking if a required field is filled.

      //return true if the value is composed by 3 digits, followed by an hyphen and then 2 letters
      if (/\d{3}-[a-zA-Z]{2}/.test(value))
        //value is valid
        return true;

      //value is not valid
      return $.Forms.Validation.GetError(I.t("errors.invalidValue"), arguments);
    }

  };

The custom validation rule then can be used inside validation schemas:

  schema: {
    property: {
      validation: ["myCustomRule"]
    }
  }

Defining AJAX validation rules

  //custom rule definition: add a property to the $.Forms.Validation.Rules object
  $.Forms.Validation.Rules.myAjaxRule = {

    deferred: true, //validation rule is deferred

    fn: function (field, value, forced) {
      return new Promise(function () {
      $.ajax({
        url: "Validation/MyValidationMethod",
        type: "POST",
        data: {
          value: value
        },
        //to keep reference
        context: this
      }).done(function (data) {
      }, function () {});
      $.ajax({
        url: "Validation/MyValidationMethod",
        type: "POST",
        data: {
          value: value
        },
        //to keep reference
        context: this
      }).done(function (data) {
        //support the response to be a boolean
        if (data === true)
          return d.resolveWith(field, [{ field: field }]);
        if (data === false)
          data = { error: true };
        data.field = field;
        if (data.error) {
          //define here the error message that you want to use
          data.message = I.t("errors.invalidValue");
          d.rejectWith(field, [data]);
        } else {
          d.resolveWith(field, [data]);
        }
      }).fail(function () {
        //SERVER SIDE ERROR DURING VALIDATION: display an error message to let the user know that the validation failed because of a system error
        //NB: the client side form could be right; but we cannot be sure of this, therefore we invalidate the field
        d.reject({ error: true, message: I.t('errors.validationFailed') });
      });
      //return a promise object
      return d.promise();
    }
  }

The custom validation rule can then be used inside validation schemas:

  schema: {
    property: {
      validation: ["myAjaxRule"]
    }
  }