Setting up and running the Pomodoro Flask application

Prerequisites Setting up a virtual environment (venv)Mac Windows Cloning the repository Installing dependencies Initializing the Database before running the application Setting the Flask environment variable Populating the Database Using a SQL Client (The application need not be running for this)Using a Python Script (The application should be running for this)Running the Application Explanation of the routes

Prerequisites

Python 3.x installed on your system

Git installed on your system (optional, if you want to clone the repository)

Setting up a virtual environment (venv)

Mac

Open Terminal.

Navigate to the directory where you want to create the virtual environment.

Run the following command to create a virtual environment named "venv":


python3 -m venv venv

Activate the virtual environment:


source venv/bin/activate

Windows

Open Command Prompt.

Navigate to the directory where you want to create the virtual environment.

Run the following command to create a virtual environment named "venv":


python -m venv venv

Activate the virtual environment:


venv\Scripts\activate

Cloning the repository

If you haven't already, clone the Git repository to your local machine:


git clone https://github.com/manasa99/demo_pomodoro.git

Installing dependencies

Navigate to the project directory (cd demo).

Install the required dependencies using pip:


pip install -r requirements.txt

Initializing the Database before running the application

If you are running your Flask app using python run.py, setting FLASK_APP=app.py is not required. The FLASK_APP environment variable is used to specify the entry point of your Flask application when you run the flask command directly, such as with flask run. Since you are running your app with python run.py, you are explicitly specifying the entry point in your run.py file, so the FLASK_APP environment variable is not needed in this case.

You typically initialize the database once before starting your application or whenever you need to reset the database. This can be done in the init_db() function or similar, and you can call this function from your run.py file or any other initialization script you have.

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But, as we will be using flask to initialize the db, we will not be required to create a method for that but rather set the environmental variable to use Flask.

Setting the Flask environment variable

For Mac


export FLASK_APP=app.py

For Windows


set FLASK_APP=app.py

Incase of powershell


$env:FLASK_APP = "app.py"

Now for the DB


flask db init  # Initialize the database
flask db migrate  # Create the initial migration
flask db upgrade  # Apply the migration to create the tables

Populating the Database

When using the database for the first time, it will be empty. You can populate the database in two ways:

You can choose either way or test both.

Using a SQL Client (The application need not be running for this)

Before Running the Application:

Use a SQL client to connect to the database.

Execute the SQL script initialise_db.sql to populate the database with initial data.

Example (for both Mac and Windows):


sqlite3 instance/pomodoro.db < initialise_db.sql

Note: If you don't have the path set for sqlite3, you can use the full path to the sqlite3.exe executable.


C:\path\to\sqlite3.exe instance\pomodoro.db < initialise_db.sql

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You might have observed that the model name we have is TimerData, but when querying through sql we use timer_data. Try to find out why!?

Using a Python Script (The application should be running for this)

While the Flask Application is Running:

Run the Python script initialize_db.py in another terminal.

This script interacts with the Flask application to populate the database.

Example:


python initialize_db.py

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Note: Ensure that the Flask application is running when you execute the Python script.

Running the Application

Start the Flask application:

You can run the application in 2 ways:

Using flask (This might not work if you have not set up the flask environment variable)


flask run

Or using python


python run.py

Access the application: Open your web browser and navigate to http://localhost:5000

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By default the flask application runs on port 5000 until or unless specified otherwise in the app.run(debug=True)

Explanation of the routes

Here's an explanation for each route in the routes.py:

/ and /<name> (GET):

Description: Returns a rendered template hello.html with a greeting message. If a name is provided in the URL, it uses that name in the greeting.

Example: / returns "Hello, world!", /Alice returns "Hello, Alice!".

/meth (GET, POST, PUT, DELETE):

Description: Returns a string indicating the HTTP method used in the request.

Example: A GET request to /meth returns "This is a GET request", and so on for other methods.

/timerdata (GET):

Description: Returns all timer data if no timer_id is provided, or returns data for a specific timer if timer_id is provided as a query parameter.

Example: /timerdata?timer_id=123 returns data for timer with id 123.

/timerdata (POST):

Description: Creates a new timer with the provided data in the request body.

Example: POST request to /timerdata with JSON data like {"name": "TimerName", "time": 60, "user_id": "user123"} creates a new timer.

/timerdata/<timer_id> (PUT):

Description: Updates an existing timer with the provided timer_id using the data in the request body.

Example: PUT request to /timerdata/123 with JSON data like {"name": "UpdatedTimerName", "time": 120} updates the timer with id 123.

/timerdata/<timer_id> (DELETE):

Description: Deletes the timer with the provided timer_id.

Example: DELETE request to /timerdata/123 deletes the timer with id 123.

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Find out what Query Params are

These routes will give you an idea of how we can use different HTTP methods, how we can use the render template and covers the CRUD for the timer_data.

Testing HTTP methods through CLI

We can directly test the GET methods through our browser. For the other methods we will be needing tools like Postman or we can also send the requests through terminal/cli.

Here is how we can do these with terminal or cli:

POST:


curl -X POST http://localhost:5000/timerdata -H "Content-Type: application/json" -d "{\"name\":\"<timer_name>\",\"time\":<time>,\"user_id\":\"<user_id>\"}"

PUT:


curl -X PUT http://localhost:5000/timerdata/<timer_id> -H "Content-Type: application/json" -d "{\"name\":\"<updated_name>\",\"time\":<updated_time>,\"user_id\":\"<updated_user_id>\"}"

Delete:


curl -X DELETE http://localhost:5000/timerdata/<timer_id>

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Replace <timer_id>, <timer_name>, <time>, <user_id>, <updated_name>, <updated_time>, and <updated_user_id> with appropriate values.