WEBVTT

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Hello everyone and welcome back.

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In this video, we're going to be going

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over how to create a post request and why
we might need to use body parser

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middleware to extract the data
from the request body.

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But first, let's understand what body
parser is and why we need it exactly.

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In node JS and Express,
when a client sends a request

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to the server, the request is
received as a stream of data.

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The data can be in various formats
such as JSON, text, or binary.

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The body parser middleware is used
to extract the data from the request body

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and make it available in a convenient
format for us to use.

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The body parser middleware parses

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the incoming request body
and extracts the data.

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Without using body parser,
we would have to manually parse

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the request body ourselves, which can
be time consuming and prone to errors.

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There are different types of body parsers

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available for different data formats
such as JSON text or URL encoded data.

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And in our case, we'll be using JSON body
parser, which is used to parse JSON data.

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So what we're going to have to do for this

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is first we're going to have
to install the body parser.

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So for that, just go to your terminal,

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make sure that you're in the root
directory of your project where you have

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server JS defined,

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and run
npm install body-parser

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this will make body parser available

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for you, and you can just
import it from here.

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And if you want to use body parser

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with your app, all you have to do
is type app use body parser JSON.

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After this, body parser will be available

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to you and we can start testing
different request types.

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So let's go over the first request type.

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We have created a Get method before

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which is used to request
a resource from a server.

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It's a read only operation, meaning
it doesn't modify data on the server.

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I need to start my server
nodemon server JS.

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Now my server is started on port 3000.

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And then if I send this request,
I'm going to receive hello world back.

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So we could create a similar
Get request and name this user.

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And here we can write,
you are getting a user data back.

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And now if we send this request

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and make it user,
we're going to get this text back.

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And if we were to use something else
that does not exist, such as, let's say,

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nata my name,
you're going to get an error back because

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we can't get the route Nata
because we haven't set it up.

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Okay, great.

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So now that we understand how to use get

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requests, let's talk about
how to use post requests.

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Post requests are used to submit data.

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It's going to submit a data to a server
to create or update a resource.

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It's a write operation, meaning
that it can modify data on the server.

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So let's create a post request
to create a post request.

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All you do is app post
and you can use any route that you want.

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Let's create one on the user here as well.

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Let's get the request parameters
and respond with something.

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If we want to see
what we send in as parameters what we

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could do is just console log, request body]

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and to send in parameters using a post

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request we can use postman so we can make

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this a post request and set this to user.

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And then we can just go to the body
of this select row data.

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And here we could just select JSON
because that's the format that we chose.

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And here we can just write some JSON data

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such as Username for example,
and it's going to be Nata.

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And if this is JSON,

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actually we need to put this as a string
so that it's a viable JSON data.

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And now if I click on send

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here in my terminal,
you're going to see username Nata printed

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out because that's
the parameter that we sent.

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If you want to send more data,
you're most welcome to.

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You can say that first name for example,

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is Nata and the last name is Vacheishvili.

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And then if you send this again,
you're going to receive the updated data,

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which means that your server,
when you make a post request,

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would receive this data and it can use
this data for anything such as updating

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database fields and making sure that new
user Nata exists in the database.

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But we're not going to be going over how
to update the databases in this section.

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If you're more interested in serverside

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development, you can take another course
on it so that you get more familiar

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with more complex functionalities that
server side development can offer to you.

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Now you see here that this is still
sending the request and this is still

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sending the request because we
haven't responded with anything.

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So if we want to respond with something,
then we just can use response send here

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and we can say that we created a user with

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first name of request body first name.

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Now let's save this,

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let's go here and send this again
and we're getting some kind of an error.

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Let's see why we're getting this error.

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Oh, because I put a comma
here instead of plus.

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So let's save this again
and send this request.

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And here you're going to see that we
created a user with first name of Nata.

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If I change this and make it Nicolas

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for example, and send it,
you're going to see Nicolas appear here,

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which means that server is responding
with the data that you sent to it.

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So this is how easy it is
to make a post request.

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Post request, put request and delete
request are very similar to each other.

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So I'm just going to
duplicate this code and call this Delete

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and I'm going to duplicate this
and call this Put as well.

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And here we're going to say that we

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updated a user with the first
name of whatever we sent in.

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And here we're going to say that we

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deleted a user with first
name of the given values.

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Great.

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So we don't need this console
logs, or maybe we do.

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Why not?
You're going to see them appear here.

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And then here we can just change the type

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and say that we're sending
a delete request and send it.

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And here you're going to receive

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an appropriate message because server will
understand what type of request you're

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making and make sure that it
runs the appropriate function.

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So here it runs we deleted a user
with first name of Nicolas.

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And here we can also send a put
request because we set it up.

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And if I send this, it will
say that we updated the value.

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And here we also see the console logs

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from these two functions that we
just ran on our servers.

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Great.
So now we understand how to make a get

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request, how to make a post request,
how to make delete and put requests as

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well, and how to send and test
the data using postman.

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Now I also want to discuss one edge case.

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As you see here, we have used the same

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route with different request types
and it works perfectly fine.

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But if I were to use the same route

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with the same request type,
such as user get, for example,

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the first instance of this is going
to run and this is never going to run.

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So let's console log,

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this is never going to run here and we
can send something different back here.

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You cannot get this response back. Great,

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so let's save this.

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Our server is rerunning because it
detected the changes and now we can just

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send in the get request for the user
and you're going to get back.

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You are getting a user data back
and that is run here because it only

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recognizes the one instance
if you have duplicated routes.

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So make sure that you never create

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duplicated routes because otherwise some
part of your code might never run.

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So that's all for this video.

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Thanks so much for watching.

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I'll see you in the next one.