Client-Server Model Example: Jane's Store

In this next series of videos, we'll walk through how client-server interactions would occur in an example of an online store. We'll see how traffic gets routed from a web client, to a web server, to a database, and eventually back to a web client.

Takeaways

• Clicking on the Polo product leads to a click event being registered by the browser, on the client computer.
• A click handler in the view would send a request to the server (in Javascript) from the client browser.
• A client could request more data and a different view to be rendered (with that data).
• A server process listens to the request sent from the view. It fetches the data and chooses what to render next, using the fetched data.

Takeaways

• The client sends a request to the server, including information about the request type and any user input data.
• The server receives the request, and uses the user input data to determine how to shape its request to the database, and sends a request to the database.
• The database processes this request, and sends a response back to the web server.
• The server receives the response from the database, and uses it to determine the view + powers the view template with the fetched data, sending it back to the client's browser.
• The client is responsible for rendering something to the user, that represents both the data and its representation.

QUIZ QUESTION: :

Match each party and its responsibility

ANSWER CHOICES:

Data representation and what the user sees

Processing data requests from the web server

Fulfilling client requests and updating the view

Responsibility	Party
Database
Web Server
Client

SOLUTION:

Responsibility	Party
Database	Processing data requests from the web server
Web Server	Fulfilling client requests and updating the view
Client	Data representation and what the user sees

QUIZ QUESTION: :

In the left-hand column below, you'll find a sentence that describes what we just learned. See if you can fill in all the blanks to complete the sentence.

ANSWER CHOICES:

The __

receives a request from the __

and sends a request to the __

which sends back a response to the __

which then sends back a response to the __ .

Sentence	Fill in the blank
web server
client
database
web server
client

SOLUTION:

Sentence	Fill in the blank
web server	The __
web server	which sends back a response to the __
client	receives a request from the __
client	which then sends back a response to the __ .
database	and sends a request to the __
web server	The __
web server	which sends back a response to the __
client	receives a request from the __
client	which then sends back a response to the __ .