README.md

ProjectY-Flask-03: Handling Routes and Templates with Flask Web Application and If and For Structure

Purpose of this project is to have introductory knowledge of how to handle routes and use html templates within a Flask web application on Amazon Linux 2 EC2 instance.

Learning Outcomes

At the end of this project, we will be able to;

• install Python and Flask framework on Amazon Linux 2 EC2 instance

• build a simple web application with Flask framework.

• understand the HTTP request-response cycle and structure of URL.

• create routes (or views) with Flask.

• serve static content and files using Flask.

• serve dynamic content using the html templates.

• write html templates using Jinja Templating Engine.

Outline

• Part 1 - Getting to know routing and HTTP URLs.

• Part 2 - Write a Web Application using If conditions and for loops

• Part 3 - Write a Web Application with Sample Routings and Templating on GitHub Repo

• Part 4 - Install Python and Flask framework Amazon Linux 2 EC2 Instance and Run the Hello World App on EC2 Instance

Part 1 - Getting to know routing and HTTP URLs.

HTTP (Hypertext Transfer Protocol) is a request-response protocol. A client on one side (web browser) asks or requests something from a server and the server on the other side sends a response to that client. When we open our browser and write down the URL (Uniform Resource Locator), we are requesting a resource from a server and the URL is the address of that resource. The structure of typical URL is as the following.

The server responds to that request with an HTTP response message. Within the response, a status code element is a 3-digit integer defines the category of response as shown below.

• 1xx -> Informational

• 2xx -> Success

• 3xx -> Redirection

• 4xx -> Client Error

• 5xx -> Server Error

Part 2 - Write a Web Application using If conditions and for loops

• Create folder named flask-03-handling-routes-and-if-for within my-repository repo

• Create folder named Flask_if_for_structure within flask-03-handling-routes-and-if-for repo

• Create python file named app.py

# Import Flask modules

# Create an object named app

# Create a function named head which shows the massage as "This is my first conditions experience" in `index.html`
# and assign to the route of ('/')

# Create a function named header which prints numbers from 1 to 10 one by one in `index.html`
# and assign to the route of ('/')

# run this app in debug mode on your local.

Part 3 - Write a Web Application with Sample Routings and Templating on GitHub Repo

• Create folder named flask-03-handling-routes within flask-03-handling-routes-and-if-for repo

• Create python file named app.py

# Import Flask modules

# Create an object named app

# Create a function named home which returns a string 'This is home page for no path, <h1> Welcome Home</h1>'
# and assign route of no path ('/')

# Create a function named about which returns a formatted string '<h1>This is my about page </h1>'
# and assign to the static route of ('about')

# Create a function named error which returns a formatted string '<h1>Either you encountered an error or you are not authorized.</h1>'
# and assign to the static route of ('error')

# Create a function named hello which returns a string of '<h1>Hello, World! </h1>'
# and assign to the static route of ('/hello')

# Create a function named admin which redirect the request to the error path
# and assign to the route of ('/admin')

# Create a function named greet which return formatted inline html string
# and assign to the dynamic route of ('/<name>')

# Create a function named greet_admin which redirect the request to the hello path with param of 'Master Admin!!!!'
# and assign to the route of ('/greet-admin')

# Rewrite a function named greet which which uses template file named `greet.html` under `templates` folder
# and assign to the dynamic route of ('/<name>')

# Create a function named list10 which creates a list counting from 1 to 10 within `list10.html`
# and assign to the route of ('/list10')

# Create a function named evens which show the even numbers from 1 to 10 within `evens.html`
# and assign to the route of ('/evens')

# Add a statement to run the Flask application which can be reached from any host on port 80.

# Write a template html file named `greet.html` which takes `name` as parameter under `templates` folder

# Write a template html file named `list10.html` which shows a list counting from 1 to 10 under `templates` folder

# Write a template html file named `evens.html` which shows a list of even numbers from 1 to 10 under `templates` folder

# Create a folder named `static` under `hands-on/flask-03-handling-routes-and-templates-on-ec2-linux2` folder and create a text file named `mytext.txt` with *This is a text file in static folder* content.

# run this app in debug mode on your local. Do not forget to change debug mode to publish mode before you push to the Github repo

• Add and commit all changes on local repo

• Push folders to remote repo my-repository on GitHub.

Part 4 - Install Python and Flask framework Amazon Linux 2 EC2 Instance and Run the Hello World App on EC2 Instance

• Launch an Amazon EC2 instance using the Amazon Linux 2 AMI with security group allowing SSH (Port 22) and HTTP (Port 80) connections.

• Connect to your instance with SSH.

• Update the installed packages and package cache on your instance.

• Install Python 3 packages.

• Check the python3 version

• Install Python 3 Flask framework.

• Check the versions of Flask framework packages (flask, click, itsdangerous, jinja2, markupSafe, werkzeug)

• Download the web application file from GitHub repo.

• Run the web application

• Connect the route handling and templating web application from the web browser and try every routes configured

• Open the static file mytext.txt context from the web browser

• Connect the route handling and templating web application from the terminal with curl command.