Asp net which validator failed

If you are not already working with a WebMatrix template like Starter Site that includes the library, create a Web Pages site that's based on Starter Site. Then copy the. In markup, for each element that you're validating, add a call to Validation. For field. This method emits attributes that are used by client-side validation. Rather than emitting actual JavaScript code, the method emits attributes like data-val These attributes support unobtrusive client validation that uses jQuery to do the work.

Not all validation checks run on the client. In particular, data-type validation integer, date, and so on don't run on the client. The following checks work on both the client and server:. In this example, the test for a valid date won't work in client code. However, the test will be performed in server code. You can control how validation errors are displayed by defining CSS classes that have the following reserved names:. If you include this style block in the example pages from earlier in the article, the error display will look like the following illustration:.

If you're not using client validation in ASP. The CSS rules come in pairs, such as validation-summary-errors and validation-summary-valid. These pairs let you define rules for both conditions: an error condition and a "normal" non-error condition.

It's important to understand that the markup for the error display is always rendered, even if there are no errors.

For example, if a page has an Html. ValidationSummary method in the markup, the page source will contain the following markup even when the page is requested for the first time:. In other words, the Html. Similarly, the Html. In some situations, displaying an error message can cause the page to reflow and can cause elements on the page to move around. The CSS rules that end in -valid let you define a layout that can help prevent this problem.

For example, you can define field-validation-error and field-validation-valid to both have the same fixed size. That way, the display area for the field is static and won't change the page flow if an error message is displayed. Sometimes you have to validate information that doesn't come directly from an HTML form.

A typical example is a page where a value is passed in a query string, as in the following example:. In this case, you want to make sure that the value that's passed to the page here, for the value of classid is valid. You can't directly use the Validation helper to perform this validation. ErrorMessage End If Next. Nitin Nitin 41 1 1 bronze badge. Sign up or log in Sign up using Google.

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Related Hot Network Questions. Question feed. Stack Overflow works best with JavaScript enabled. NET calls validation attributes, it knows which DTO fields those attributes are attached to and allows you to extract this information in the model state validator.

All the validation rules are contained in the domain layer, where they should be. You can create an attribute for the CityOfOrigin property, too.

This attribute will check the rules related to the city of origin as a whole those invalid city-state combinations I mentioned earlier. Not only does this approach brings the declarativeness back, it also drastically simplifies the controller:. Note the use of. Value in '1. Create returns a Result instance, and if that result is failed, Value will throw an exception. By the time the DTO comes to your controller, it should already be validated by the attributes.

One last thing. It inherits from ASP. Also note the [ApiController] attribute. By putting this attribute on the base class, you apply it to all subclasses too. NET invokes it automatically for all controllers marked with the [ApiController] attribute, which in turn triggers your custom model state validator. Introducing custom validation attributes that would delegate the actual validation to value objects.

The combined approach helps you both keep the declarativeness and contain the domain knowledge in the domain layer. Combining ASP. This is a continuation of the article series about some more advanced error handling techniques.

Keep track of all known errors, React to those errors differently. Input validation using ASP. Name ; student. Input validation using Value Objects A more DDD-friendly approach to input validation is to introduce Value Objects containing all the knowledge related to the corresponding domain primitives.

Trim ; if email. ValueIsTooLong ; if! Here's the catch: the RequiredFieldValidator will behave in this manner regardless of where the page is posted back to the Web server from. Thus, if a user clicks the second button control, even though it is at a different point in the page, the RequiredFieldValidator at the top of the page will prevent the page from being posted back to the Web server. The scenario above represents just a single example where it would be helpful to be able to manually and conditionally enable and disable the ASP.

NET data validation controls. You can easily disable validation controls by simply setting the Enabled property of any of the validation controls to false. But, disabled validation controls will not perform data validation. However, validation controls that you've disabled can be enabled at any point that you need their services.

If you need to manage when data validation controls are enabled, a quick solution is to simply disable them by default. In the server-side function member that will be processed by the event that causes the page to be posted back to the Web server, you can take steps to validate the information that was submitted. You first want to re-enable the needed validation controls. Next, call the Page. Validate function member provided by ASP. This function member causes all of the validation controls on the Web form to validate the information submitted to the Web server.

Finally, check the state of the Page. IsValid property. If any of the validation controls on the Web form were unsuccessful in the validation process, the Page. IsValid property will contain a value of false. The steps mentioned here give the developer complete manual and conditional control over when you want to enable the data validation controls. The snippet below illustrates the steps mentioned here. You can also manually and conditionally control data validation when you're performing client-side validation by simply having the script that performs the validation return a true or false.

However, taking manual control over when validation occurs on the user's computer isn't common since the Web server will always process the validation controls.

Note that the RequiredFieldValidator control is the only data validation control that will fail the data validation process if the control that it is linked to contains no value. The CompareValidator , RangeValidator , RegularExpressionValidator , and CustomValidator will all pass validation if the value contained in the linked control is a valid value as well as if there is no value in the linked control. For this reason, you may need to combine multiple validation controls and link them to the same target control to be validated.

The validation controls are not actually combined in any way, but you can link multiple validation controls to the same target control to validate that target. In this manner, you can link both the RequiredFieldValidator control and one of the other validation controls, such as a RangeValidator control, to a TextBox control so that the TextBox must have a value entered in order to pass validation.

Validating the data entered by users is a vital part of any software application. Data validation processing prevents wasting time processing invalid data and guards the integrity of a data store by only allowing valid data to be entered into an application.

Microsoft's ASP. NET data validation controls do a superb job standardizing the means of validating data entered by a user over the Web. My Subscriber Account Advertise Write.

Training Home State of. Staffing Home Looking for Staff? Looking for Work? Contact Us. Dark Kimbie. Published in:. Filed under: ASP. NET WebForms. There are six controls included with ASP. NET that simplify data validation. Figure 1. Figure 2. TextBox and RequiredFieldValidator controls Another commonly used attribute of the RequiredFieldValidator control is the EnableClientScript attribute, which determines if the RequiredFieldValidator control performs validation on the user's computer or not.

Figure 3. CompareValidator controls You can also use the CompareValidator control to compare the value in one control to the value in another control. Figure 4.