Beginner PHP Tutorial - 70 - Working with $_POST Variables Video Lecture | PHP for Absolute Beginners: From Novice to PHP Master - Web Development

hello this is Alex from PHP academy'
dorg and in this video for the new
Boston I'm going to be talking about
post data now we've already looked at
get data and forms and then form
security but with we've been we've been
currently displaying all of our data the
variable names and the variable data in
our URL so our structure has been
index.php and we've had things like date
equals Monday days equal date was Monday
and then blah blah so on so what happens
if we are submitting something like a
long registration form or let's just say
a user has to go on a page and submit a
long area along there sort of selection
of text in a text field so they were
typing out say a lot a long description
of themselves for this purpose it's not
a good idea in any means to use get but
what we do is we use something called
post and this uses a different method it
uses the HTTP POST method and this
processes the data is sensitive to
directly to the form and doesn't include
it in the URL itself so it's great for
things like passwords it's great for
things like long registration forms as
well it's good to note that get actually
does have if you were to use variables
like this this a lot of browsers and web
servers have limits on how much get data
can be processed at once and as well
when you're using things like file
uploads you need to be processing the
file data through a form into a page and
use post as well as another attribute to
the form field which is called an Inc
type but we're not going to be going
into that until we deal with form field
uploads so we're going to take a look at
an example and this example is going to
be typing in a password and in this case
we're going to be submitting the
password we're going to be creating a
form first rule down here we'll be
submitting a password and checking it
and we're going to be telling the user
you know is the password correct so
we're going to start off by setting up
our form and I have the form action and
the method as usual and remember the
form action we can either go to another
PHP page or we can stay on the same one
in this case I'm staying on exactly the
same one so we're submitting all the
data inside this form to index.php the
method though instead of get is going to
be post and this automatically means
that the data is not going to be sent
where it's going to be sent as post it's
not going to centers get so let's say
password and we break down and we have
an input type now this time we're not
going to choose text because what would
happen would be is we would be able to
see anything we typed in here however we
are going to choose the type password
and this means that the browser
interprets this as a password field and
you can no longer see anything in there
so that's the interesting if you didn't
already know how to do that the name of
this is going to be password okay we're
going to break down a couple more times
and we're going to be an input type
submit' value equals submit just as we
did in the last example
so as this stands we're submitting a
password in this form when we click
Submit so as prior the but as to the
previous example with get I type
something in here click submit and we
saw it appear here however now if I was
to type say password in here and click
Submit we've actually submitted this now
to the form the data has been submitted
however is not visible up here and
obviously at the moment not visible on
the page because we haven't done
anything with the data now just to show
you the example I'm going to echo out
dollar underscore and this time post and
password remember this name here
corresponds to the name that you've
given the form field so let's refresh
the page type in and hidden for exam
pull and click Submit you can see that
hidden is now displayed okay but it's
still not displayed up here so what can
we do with this we can again check that
the form has been submitted so we say if
is set it's set and we say dollar
underscore post this time password we
execute in this block here so if we've
submitted and the password has been has
been sent or the form field data has
been sent we now need to grab that so
I'm going to say password equals dollar
underscore post password now as
discussed in the security video relating
to forms we could do the HTML entities
just here however we're not actually
displaying this password back out to the
user we're just going to process it down
here and check that it's equal to a
preset password so the password I'm I'm
going to say is passed one two three
okay
so the password must be equal to pass
one two three for us to validate it so
now what I'm going to do is I'm going to
say if password corresponding to this
variable which then corresponds to this
here because we're taking the post data
which then corresponds to what the users
typed in so if the password is equal to
match say something otherwise say
something out and what we're going to
say in here is echo that is correct
and otherwise we're going to say that is
in correct okay
so let's test this out we'll go back to
the index dot PHP page will click Submit
and it says that is incorrect
we haven't actually checked for the
existence here and but we can do that we
can say here if this is not empty
password do all of this down to here
and then we can indent this so this
reads as if it's set set a new variable
called password to the posted password
if it's not empty do all of this and
then and then otherwise I mean can you
see in my text editor where when I click
to the end of this curly bracket here
that highlights in red this also
highlights in red so I can see that this
starts here and ends here therefore I
can do else please enter a password okay
so um let's go back and back onto our
page now I'm going to submit it without
entering anything and it says please
enter a password now I'm going to enter
a password just absolutely anything into
the form and click submit that is
incorrect
now if I was to type pass one two three
and I was to click Submit we've
validated that as correct
therefore we're displayed with the error
of the error the message that is correct
so we've posted a password through this
form we've used the post method with the
HTTP POST method which doesn't display
here and has allows us to propel us to
process it in secret now I'm not going
to show you an example but if you were
processing say a long amount of data
you'd also use the post as well as a
file uploads like a discussed earlier
but that will be later on in the series
so this is basically posting variables
in PHP