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This video serves as a conceptual overview of form validation, referencing its importance in preserving data integrity in our database and application.
Whenever an application
receives a request,
0:00
it is important that we ensure
that the request is valid.
0:02
This comes in many forms.
0:06
The web server will ensure that
the HTTP request was crafted
0:07
in a way that constitutes valid HTTP.
0:11
In the future, we'll ensure that
the requestor has a right to make changes.
0:14
For example, we might validate that the
requester is a currently logged in user.
0:18
But here, what we want to validate is that
each piece of information that is inserted
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is in the correct format.
0:28
For example, for adding a category, we
might want to ensure that a category name
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never exceeds 15 characters and
is at these 3 characters in length.
0:34
Even more, we'd want to make sure
a category name was provided at all.
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This whole process is
called data validation and
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is part of every modern
stable application.
0:46
Whether or not it's a web app and
whether or not it's written in Java.
0:49
In the context of a web application,
two forms of validation exist,
0:53
client side and server side.
0:58
Client side validation is
written in JavaScript.
1:00
This allows for immediate feedback
before an HTTP request is ever sent
1:03
upon clicking a form submit button.
1:08
That is, the browser displays
an error without the server
1:11
ever having to check it.
1:14
Server side validation
happens on the server.
1:16
And in our case,
would be written using Java code.
1:19
Now, regardless of whether or not your
application has client side validation for
1:22
sufficient security, you should always
include server side validation.
1:26
Let me repeat that.
1:31
Your web application should always
include server side validation.
1:33
This ensures that data that reaches
the web server is indeed valid.
1:37
This prevents malicious and
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nonsensical data from being planted into
your database or on your web server.
1:44
Remember, even though you intend for users
to interact with your web application
1:49
through a browser,
as you saw in HTTP Basics.
1:53
You can reach a web server simply
with programs like Telnet.
1:57
In this case, there's no client side
validation since the validation
2:01
would have been written for a browser.
2:05
The user has cut out
the browser with Telnet and
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has therefore, cut out your
client side validation as well.
2:10
Okay, you get it.
2:14
Always include service side validation.
2:15
Next, we'll look at exactly how
we add that to our Spring app
2:17
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