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so welcome back to the mac part and now
i'm going to be telling you exactly how
you can upload download and delete
images from parse and really you could
do this for any file but i'm doing this
for an image now as you can see over
here if I just go over to my chrome and
if i go into enger know which is a photo
sharing site as you can see i have
hosted it pictured me at Ripley's
Aquarium actually I was there just I
think last month and there might maybe a
video about it soon but I didn't mean to
say that anyway ok let's continue as you
can see I put a little picture of me
from there I posted on amber and now I'm
going to be uploaded mr. Parsons in code
we're going to download it put it into
an image view and then delete it off a
puss so let's get started first of all
it's going to parse because that's
pretty much where we're going to be
doing this so parse com okay so let's go
to our apps and let's just go to our
core of our image upload I just created
a quick database called image upload and
under it in its core I've created a
class called photo which has an image
name as string and image file as file /
l actually columns and now we're going
to be adding some rose to it with some
files so let's begin so first of all
let's explain the functionality of the
app basically what happens let's just
run this on a simulator what's going to
happen is it just shows a blank screen
for a while and then once it's uploaded
the image to parse you can click on load
image it shows you the title of the
image in a message box and then it shows
you the actual image itself and again
this is from par so I'll prove it to you
in just a second but let's just close
that down and now let me explain exactly
how it works and on the same at the same
time I'm going to be showing you what's
happening in parse so what's happening
is on view did load we're calling a
function called upload image now
essentially upload image is doing is
first of all we're defining constant
called URL this is
URL for our imgur image then we're
finding a constant called data which is
equal to the NS data which is equal to
the contents of the URL nsurl which is
taken from a string which is our URL
then we're forcing that to be unwrapped
and then forcing the NS data to be
unwrapped because we know in this case
that it will be correct or there will be
something in it then we're declaring a
constant called image file a type PF
file which is going to be equal to a new
PF file and we're running the name data
initializer on it so we're giving it the
name tanmay ripley's jpg and we're
giving it the data the data that we just
extracted from the URL then we're just
doing a force dry image file dot safe
and so now what's happening is we're
saving this image file locally now we're
doing is we're creating a PF object
called user photo and basically the its
class name is called photo because if I
show you over here i created this class
called photo ok now we're setting user
photos image name to me a trip with
aquarium of canada then we're setting
the image file to the image file that we
just created the PF file constant and
then we're doing a first try user photo
dot safe and so now what we're doing is
we're saving the user photo the entire
thing online properly ok so now let's
run the app as you can see you now know
what's happening in the background we
have now successfully uploaded the image
now because this button has appeared ok
so now what I'm going to do is I'm going
to go to parse and if i refresh as you
can see we can see image name me at
ripley's aquarium of canada and the
image file is Tammy Ripley's and then I
can download that of course and look at
it ok perfect and now what's going to
happen is let's just take a look at the
IP action for the button clicked now
this IP option I be action calls
download image and delete image and
essentially what happens a download
image will download the
as it says and put it into the image
view and delete image will actually just
delete the image off of parts and so I
can just get to show you a sample of
that it does this yeah ripley's aquarium
of canada breakfast ok so now continuing
what's going to happen is in download
image we are creating a new PF query for
a class named photo then we are creating
an object which is the first object we
get from that query then we're creating
a UI alert controller with the title
title an image a message as the image
name itself that we got from pars and
we're giving this the alert style then
we're giving it then we're creating
actually a UI alert action with title
nice of style canceled and has no
handler and then we're adding this to
our UI alert controller then we are
presenting this UI lower controller on
our screen doing using self represent
view controller and then the controller
make sure it's animated note completion
handler then we're doing is we're
running the we're actually creating the
variable for the image which is equal to
just a new generic UI image i guess i
could also just do UI image that works
much better it takes bit less memory
doesn't really matter though anyway
continuing then we're saying we're
creating a new constant called file
which is equal to object the object for
key image file a zanu-pf file and so now
what we're doing is we're taking the PF
file that we sent over to parse we're
taking it back and we're extracting it
into a PF file then what we're doing is
we're saying a mage is equal to UI image
which is itself from data which is
itself from a URL which is itself from a
string and then we just get the files
URL from parse we force unwrap that then
we force unwrap the nsurl then we force
unwrap the NS data then we force unwrap
the UI image that worked ok looks
complicated but once you've just revised
over a few times it isn't I promise
anyway then we're sending the image use
image to the image that we just got and
in case you were wondering the image
view iboutlet
is up over here and then as you can see
we have the function delete image which
is called next after download image
which essentially just creates a new PF
query of class name photo oh we get the
first object from that query and then we
force try to delete that object and that
is as simple as that now as you can see
if I run this app one more time let's go
to parse let's refresh as you can see
right now there's nothing in photo but
once our app is done loading as you can
see if i refresh as you can see that
there is something in photo ok now let's
just click on load image as you can see
me at ripley's aquarium of canada is the
exact title we gave it over here me at
ripley's aquarium of canada okay now
let's click on the nice button so it
continues it shows me the image that we
just downloaded from cars and now if we
refresh in parts it's gone because we
have deleted it and that was it for this
tutorial now in the next tutorial I'm
going to be teaching you how to do this
was a much more elegant you why this was
just a bare-bones proof of concept
because I just wanted to get this out
ASAP and so next I'm going to be putting
a UI to it so you can actually select
images and take images to upload and
then see them in a list then later i'm
also going to be integrating with them
into my chat app and as I long-promised
I'm also going to be integrating push
notifications and better private chat
into my chatting app and so olds all
those will be in separate parts and
we're going to merge them together ok so
that's it for this tutorial and
explanation for its next parts ok so if
you enjoy please make sure to leave a
like you can also comment down below if
you have any questions suggestions app
ideas really anything you can also email
me if you have any of those and you can
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in one of my next videos you can also
contact me via Twitter at Ted umani
again all my points of contact will be
in the description the source code will
also be in the description on a github
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help out quite a bit and that's going to
be it for this tutorial goodbye