When to start session
28: How to Start a Session in PHP | PHP Tutorial | Learn PHP Programming | PHP for Beginners
today we're going to talk about
something called a session inside PHP
and the session is a little bit
different than a session variable which
we talked about in the last episode now
let's pretend for a second that I want
to create a session variable and I want
to access this session variable and use
it inside my page here now in order to
do that we're going to have to have a
session running inside our page because
otherwise we can actually gain access to
our session variable on every single
page inside our website and an example
you guys might want to use this let's
pretend for a second that we have a
website with a login system and I type
in my username and my password and then
I hit login now if I did actually you
know choose the right username and
password and I want to log in now in
order to actually you know make the
website remember that we're locked in
we're going to have to save our username
or something that our website will
remember inside our session otherwise
the website can actually remember that
we're locked in so to give you guys an
example let's actually go ahead and
create a session variable inside my
document here called index to PHP and I
do want you guys to bear in mind that I
do actually have a navigation in here
and I have another page called contact
the PHP so if I do actually go ahead and
refresh my browser you guys can see we
just have a navigation in here at home
and I have contact and I can click
between them if I want to now going back
to my front page I'm going to go down to
my body tag and I'm going to create a
session variable so I'm going to say
variable underscore session brackets and
I'm going to set it equal to some kind
of string now inside my session brackets
I'm going to call this one username like
so and it's going to be equal to Danny
nine four eight a just because that kind
of looks like a user name so now if I do
actually go underneath here and echo
this thing up here you know the actual
name of the session like so inside my
front page
you guys will notice that we get Danny
nine four eight a
but if I were to go into my contact page
now you guys can see we get nothing well
we do actually need to include the echo
inside our contact page of course so if
I go into my contact page paste it in we
should be able to you know spit out our
username but we get an error message
instead and that's because our website
doesn't remember our session variable
called username and we need to do that
in order to be locked in so a way to get
around this is to actually have a
session started that saves our session
variable and allows for us to access it
on every single page inside a website so
what I'm going to do in order to do that
you know to actually start up a session
is to go at the very top of my page here
and create a short piece of code I'm
going to start off my PHP tags at the
very top and inside the PHP tags I'm
going to say session underscore start
parenthesis now that I have these I will
actually have my session variable saved
inside my session which I started at the
very top of the page here so if I go
ahead and copy my session variable and
paste it on top of my contact page I
should actually be able to remember the
actual user name so if I go back to my
home page you guys to see okay now we
just set it as Danny nine four eight a
if I go to my contact page now it's in
there as well so using the session start
function we can actually start up the
session on every single page and set our
website and it will remember our user
name which we need in order to be locked
in so just to give you guys a small tip
for creating session starts now a
typical thing to do would be to split
your you know website into different
documents for example am i split my
entire header inside a document for
itself and then link it or maybe
included on top of my pages with an
include function that we do actually
have inside PHP and by doing that and
then starting up the session inside the
header the PHP but do actually have a
session running on every single
page that has a header attached to it
inside our website so we will
automatically have a session started
every single page you don't have to copy
paste it in the page just like I just
did here but I'm Lacey in this episode
so I just kind of did that instead so
this is the basic idea behind sessions
and this is actually very important if
you want to create something like a
locking system because without a session
you can actually be locked in or at
least only on the front page or wherever
you actually do log in so you need to
have this word to remember that you're
locked in inside the whole website now
just to show you guys and this is more
of a bonus thing but an example of you
know being locked in could actually be
to create for example a let's say we
have the front page here and I make a
check that says you are locked in so I
can actually go down here and say if and
execrate an if statement whoops that was
too many I can say if is set inside my
condition in here I can say if is set
and we have something called a session
username set like so then I wanted to do
this down here now also let's say for
you guys always check for errors first
so I'm going to say if the username has
not been set then do this otherwise
we're going to do something else
underneath here so if the username has
not been set inside our session then
echo you
I'm totally screwing up here you are not
locked in now underneath Dave statement
I'm going to say else and I'm going to
say echo you are locked in so this would
actually be an example of if you
actually locked in you display one type
of content inside your website if you're
not locked in you're going to display
another type of content so I'm going to
go and save this
go to my website refresh
and let's actually make sure we have
everything like it should be well sign
out in the right page there we go I'm
inside my front page now and does
actually say you are locked in because
we do X have this one set inside our
session now if I were to actually go in
and delete my session here like so and
actually delete my session start up here
like so refresh the website it does
exactly say you are not locked in
because we are in fact not locked in but
now we do actually have a session you
know set in here again and it will say
you are locked in so and again this was
more of a bonus to show you guys you
know to give you guys an idea about how
the whole locked in thing works now
we're actually getting to the point
where we can start creating a login
system and we will actually do it after
a couple more episodes we just need to
talk about a few more things such as how
to actually use tables to create
something like a locking system where
you type in your username and password
and we also need to talk about how to
create an actual user table inside a
real database and that's going to be a
very short episode we're not going to go
very in-depth in databases in PHP but it
will actually at some point start up a
tutorial series on something called SQL
and databases where we will actually
talk about how to set up you know
complicated databases so hope you guys
enjoyed this episode and I'll see you
guys next time
