Hello, in this video we are going to look at validating form detail with PHP. So we'll be getting this data tomorrow, whether it's from a get variable or a post variable. But so far we have an acronym really validating the data through to validate. So we're actually going to create a function. So we'll say function, we're gonna say Valley date. And this will take one, you know, argument and this is the data that needs to validate.
And this free validations that we are going to do, we're going to say data is equal to itself. We're going to do trim and this basically is remove empty space at start and at the end, then we're going to say once we trimmed it, the next day is going to be to strip two slashes and I will provide some data Once I've done all this, and we can actually see running and next what we want to do is gather data. Once it's trimmed a strip, the slash is equals to itself with the HTML special chars. You'll see what this does. So if for example, we you know, have username only get rid of password running, we need the lawn, donate this one. So imagine if I just had this particular this one right here.
I'm not utilizing this yet, but I will be in a second. As you can see, undefined index was you know, handle was sort of handle that as well warm up fully handling me but we'll be partly handling it. And if I type in Hello, hello, fine. If I put in a no B The old Hello, world, I think See, it comes out both sort of feels cool. But you know, websites can be hacked like that. So one of the things that could happen is if you use the create the left side with exactly, you know, username, for example.
So all they input it in there for making the making notes or some sort of blog post. And or, you know, imagine if it's a comment on a website or Facebook, they store them in a database when they get that back. We don't want any styling that they've put in there, maybe accidentally, maybe they're just sharing code. We don't want that to disrupt the rest of the website. So what we can do is the transcripts like HTML special characters, what that will do so if we say that we want to return this, but we want to return Dollar data. So, dollar use.
So once we actually get the data, actually we can just do it here we can just say validate is equal to this conference validation, so no three wants to do that. As you can see, we still get the original data, it just basically removes or replaces, you know the special you know, these characters with characters that must be displayed but not run. And if I was to do this again, but now, perspective stuff, Aleksey remove the spaces as well as strips, slashes as well which can be used to you know, no D eliminate certain tags was basically close these tags off, but again, they'll still show it, you'll just prevent it from basically disrupting it. hacking the rest of your website. That's the beauty of this, you won't actually ruin anything, you just prevent it from from mess it up. So one thing I wanted to show you was no, we can check if we actually get if we're, you know any variables have been submitted.
So we can do dollar underscore server. And we can say request on the spool method, and we can basically say, does this equal to get post, send us the wire get and I want to do this. If I run it, there we go. But if I do that, we still say on defining the to do range Okay, so this will only work for post five I will actually remove this and you can see what happens, we get undefined index. Now if we put this it only checks it if some data has been sent via post. And now let's actually send some data it will say, undefined index username should be posted slowly but something in there There we go, which is fantastic as you can see it is working.
But there is a problem. What if this is some other username like other than our whether the name is safe is H and I reload it will still get the error because we say username online 14 Okay, this doesn't exist or it hasn't been stored in the post array. I'm going to be covering that in the next video. So feel free to check that out. If you have any questions, feel free to call me a message and as usual on forward to seeing you in the next video.