Validating forms in perl
Data validation is important to the proper functioning of any application.
In other words, if the supplied input, matches the criteria laid forth in the whitelist the input will be treated as valid and will be processed by the application.
You can use a client-side scripting solution like Java Script that performs certain validation rules before submitting the form data.
The advantage to this approach is that the user does not have to wait for the data to be submitted to your application, validated and returned.
In a blacklisting approach, any input that matches the criteria laid forth in the blacklist is considered an invalid input and will result in an error message, while any input that does not match the blacklist criteria is treated as a valid input and passed through for further processing.
Let’s take the hypothetical example of writing a piece of software that serves as the backend for a Web-based forum.Due to the large variances in types of content that we may want to allow users to post, it may be difficult to whitelist valid forum posts.