Validating data input

23 Sep

Defining validation rules makes form handling much, much easier.

There are many different aspects to the validation process.

What we’ll cover in this section is the model side of things.

Essentially: what happens when you call the save() method of your model.

Schema validation allows you to validate incoming messages against a set of configurable Extensible Markup Language (XML) schema documents.

The data that a user enters in a user interface might or might not be appropriate to the application.

Data Validation Example | Create Data Validation Rule | Input Message | Error Alert | Data Validation Result Use data validation in Excel to make sure that users enter certain values into a cell. On the Data tab, in the Data Tools group, click Data Validation.

In this example, we restrict users to enter a whole number between 0 and 10.

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You can use Excel's Go To Special feature to quickly select all cells with data validation.In Flex, you use a validator to ensure the values in the fields of an object meet certain criteria.For example, you can use a validator to ensure that a user enters a valid phone number value, to ensure that a String value is longer than a set minimum length, or ensure that a ZIP code field contains the correct number of digits.Data validation is an important part of any application, as it helps to make sure that the data in a Model conforms to the business rules of the application.For example, you might want to make sure that passwords are at least eight characters long, or ensure that usernames are unique.In typical client-server environments, data validation occurs on the server after data is submitted to it from the client.One advantage of using Flex validators is that they execute on the client, which lets you validate input data before transmitting it to the server.Schema validation occurs before serialization or encryption of the message.In order to reduce development time, you can start by using the schema file that is generated when you add a service reference to your client.Most often, the purpose of data validation is to ensure correct user input.Validation can be defined by many different methods, and deployed in many different ways.