Custom textbox validating user input

When collecting input from a user, it is important to ensure that the input received meets the requirements of the system.

For example, when placing an order at a site like it is vital that the user supply certain required bits of information, such as the shipping address and their payment information.

In this demo, I used the Iconic font from Ico Moon.

The great thing about using Ico Moon is that the Ico Moon App lets you can choose only the icons you need to use, and package them into a lightweight file.

To display the icon after the input field, I am tempted to just use pseudo-class and pseudo-element all together like, to make your code more semantic.

There’s the easy way to customize the message text, and then there’s the easier way.

The validated result will be displayed outside of the form via binding, which will only update when the user input is valid.

) pseudo-element to insert some content before (or after) the content of an element.This is how we will implement the interface in our component: The interface is just a ‘contractual obligation’ to provide methods that can be called somewhere else.So we now need to register our component as value accessor provider so Angular knows that it can call these methods when used in a form.Building any application that works with User Input cannot be complete usually without having some sort of validations for the input values. There is an interesting discussion around WPF validation on Paul Stovell's blog.Martin Bennedik has written a WPF Validation Block over Microsoft's Enterprise Library 3.0.