JavaFX Java GUI Tutorial - 33 - Initialize; Binding; and Reusable Components Video Lecture | JavaFX Java GUI: Learn to build Powerful Applications - Front-End Programming

alright guys in this video I'm going to
show you how to use an initializer and
also how to perform a binding in F X M L
now binding an F XML is a little bit
different than how we learned before but
you guys are going to catch on real
quick and before we get started I'm just
going to delete everything from the last
tutorial so all of this button stuff so
I pretty much have an empty controller
and we can actually just delete this
entire button right here since we don't
really need it alright so what is an
initializer an initializer is for
whenever you want to run code right
after your view loads so the program
starts this view loads right here and
you want to run some code behind the
scenes maybe load in some user data from
database or if they have like any save
files you can load those in whatever so
in order to do that we actually need to
implement and right here initialize bolt
so it's saying okay you have a little
error right here because whenever you
use initialize Bowl you actually need to
implement this one method called
initialize so basically this is the
method that's going to be called as soon
we tighten this up as soon as this view
loads so if we just do something like
system.out.print line I'll just say um
like loading user data so now let's just
go ahead and run this and check it out
so the view loads right like that and
without having to call any methods
manually it called initialized so there
you go simple enough that was easy to
understand now let's go ahead and learn
about binding now we already know what
binding is we can essentially tie a
property of one object to a property of
another so I'll just show you guys a
real quick example say that we wanted to
tie the text of this label to this one
right here why would we want to do that
I'm not sure but that's what I'm going
to do
in this tutorial so the first thing we
need to do is for the source we need to
give it an ID so we can reference it so
FX ID I'm just going to name this like a
first label
alright simple enough in let me not even
include any text in here because instead
whenever we want to bind we first use
the dollar sign now whenever you see a
dollar sign it pretty much means a
reference to something else
so if we use dollar sign curly brackets
and then we type it's like an autofill
for me well I'll just copy then first
label dot text what we're saying is we
are going to grab the value a first
label text so whatever was written in
this label whatever text is on this
label and we're going to bind it to this
property right here so now these are
actually bound together whenever the
text changes on this it will
automatically get updated on the second
label so let me run that and there you
go
and since I have a little bit of time
left what I can do now is show you guys
how to use reusable objects so let me
get rid of this and then I'll explain
what they are so let's say that we're
making some kind of program we'll say
that it's a game and we're going to have
a radio group in other words we're going
to have a little option menu with three
radio buttons and the user can select a
difficulty for their game easy medium or
hard now we already learned whenever
you're looking at how to make menus that
whenever you make a radio group you put
them as part of the same toggle group
that's how your program knows that these
three options are grouped together in
the same toggle group so we just change
this to like difficulty alright so
remember for each radio button you set
it part of the same toggle group so
you're going to need to use that toggle
group over and over and over again well
any time you want to use an object over
and over and over again you actually
need to define it as a reusable object
so if you just write FX define and then
you close this then in between here you
write any objects that are going to be
reusable through your code so I know
that this is toggle group and of course
we just need to give it an ID so we can
reference it so I'll just call it
something like toggle group or like
difficulty whatever and synthesis a
single tag we can actually just end it
like that and now we can just start
making our radio buttons so radio button
the first attribute I just want to set
is the text on it and I'll just say like
a easy and then the second one is toggle
group and we need to reference this so
remember anytime we want to reference
something we use the dollar sign and
then the name of whatever you want to
reference and this is a single tag so
end it like that so again your toggle
group it isn't a parent of these radio
buttons it's actually an attribute so
instead of having to you know write it
over and over again we just make it a
reusable object and then if I change the
text like medium and hard then there you
go and you can make a button to submit
that if we want but too lazy alright so
let me run this and check it out so now
since these are grouped together notice
that we can only select one of them and
of course we could do something like
print it out on the screen or actually
use it in our program but there you go
so again any time that you want to
create an object that you're going to
reuse in your code put it in between
these FX define brackets and you can
just write each reasonable object on a
new line and simple as that