This course will be retired on August 10, 2021. We recommend "REST APIs with Express" for up-to-date content.
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REST is a way of communicating, using a combination of URL’s and what are called “verbs” to make stuff happen on the internet. You use REST all the time when you surf the web, though most people are only aware of the URL component.
There are four verbs commonly associated with REST Services:
GET
POST
PUT
DELETE
To get a sense of what the rest API
is let's first talk about rest.
0:00
Rest stands for
representational state transfer and
0:04
is a way of defining how a web
server should respond to requests.
0:08
Normally when humans interact with
the Internet they use a web browser
0:13
as a client.
0:17
The browser makes a request to
the server and HTML and CSS is returned.
0:18
It's human friendly.
0:23
Machines can also make requests
to URLs and ask for resources.
0:25
These responses are intended for
machines, not humans, so
0:30
no HTML and CSS are returned.
0:33
This type of response is
normally formatted in JSON.
0:37
A good example of this is
the Twitter app on your phone,
0:41
it makes a request to Twitter's rest API
to get the tweets before you see them.
0:44
The JSON from Twitter's API is then
formatted and displayed on your phone.
0:49
API is done only allow you to read data
but also add update and delete data.
0:53
Each of these actions can be mapped
to an HTTP verb post, put or delete.
1:00
By combining an HTTP verb with
a URL an API can do many things.
1:05
Such as post tweets,
delete emails or even transfer money.
1:11
When a set of URLs are designed to
interface with a back end program in this
1:16
way we call it a Rest API, or
application programming interface.
1:20
Let's look at the demo user interface for
our Rest API again.
1:26
I'll open up the Chrome developer tools
and then click on the network tab.
1:30
This will allow us to see what's
happening when we use our user interface.
1:36
When we submitted new
question like why is the sky
1:42
blue, our UI makes an http post
request to the URL slash questions.
1:49
This is via an AJAX call.
1:58
The server responds by inserting
a new question into the database and
2:01
returning it back so it can be displayed.
2:05
When we brought an answer up
2:14
The UI posts a request to the URL pattern.
2:21
Questions, question ID,
answers, answer ID, vote-up.
2:25
The seven responds by increment in
the specified and says vote counts and
2:29
returning the whole question
back with it's answers.
2:35
The UI can now be updated.
2:41
Now that we have a sense
of what a Rest API is and
2:43
how it works, let's plan the API
we want to build the next.
2:46
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