Assignment 1 - Todo List Backend

In this first assignment, you will write a backend to service a cloud-based todo list app. In this day and age, cloud-based products for viewing and saving various forms of content (photos, bookmarks, todo lists, etc.) are becoming increasingly popular, due to their ability to offload data from your local machine to the cloud, service your data to multiple platforms, etc.

Learning Objectives

This project aims to help you "ramp up" and get comfortable working with the following tools / technologies / concepts:

• Python as a language and a Flask as a framework
• JSON as a means of sending and receiving data
• HTTP requests and responses
• Data modeling
• Basic exposure to SQL querying
• System configuration
• Python / Command-Line-Based Testing

Table of Contents

• Academic Integrity
• System Configuration
• Organization
• Expected Functionality
• Testing Your Code
• Extending the Assignment
• Project Submission

Academic Integrity and Collaboration

Academic Integrity

Note that these projects should be completed individually. As a result, all University-standard AI guidelines should be followed.

Code Attribution and Collaboration

One of the reasons we chose Flask as an initial backend framework for students to use is because of its phenomenal support online. Looking up framework documentation and adapting the docs' sample code to suite your own needs in something we expect and want you to do, as it allows you to explore and increase your self-sufficiency regarding backend development. However, if you find code in a StackOverflow post or in an open source Github repository, then you should cite it accordingly. See the project submission section for guidelines as to where to include those citations.

System Configuration

Perform the following steps in order:

1. Check your Version of Python (should be 2.7)

You can check via:

python --version

If your version differs, then download 2.7 here.

2. Get PyPI (Python Package Index)

PyPI allows one to easily download Python modules required to run the project, as well as ones that may help you perform certain tasks in the future of the course. PyPI is essential.

3. Clone the Source Code

For this project and future projects, we will be using git. If you don't have git, you can find it here. You can clone the source code of this project by running the following:

git clone https://github.com/Cornell-PoBE/A1.git
cd A1

4. Download Virtualenv

Virtualenv helps establish an isolated Python environment. The environment allows you to separate project-specific dependencies and their versions from the Python modules installed locally on your computer. Once you have virtualenv, run the following inside of the A1 directory:

virtualenv -p python2.7 venv

This creates a virtual environment called venv. In order to enter than virtual environment, run the following:

source venv/bin/activate

The following command line prompt will indicate that you’re in the virtual environment:

(venv) >

To deactivate the virtual environment, run the following:

deactivate

Whenever you work with this project, you should always be in your virtual environment. Without this isolation, we might run into module versioning issues and other problems when trying to run your project, which creates administrative overhead.

5. Install Dependencies

At the root of directory of the project skeleton code, run the following:

pip install -r src/requirements.txt

This installs within your virtual environment all the necessary modules that are required at the beginning of the project.

6. Install SQLite

Having been given some initial exposure to SQL databases in class, the concept of "querying" data is one that we expect you to have a basic grasp of when approaching the future lectures on databases. As a result, we have decided to use SQLite in this project as our means of storing and querying data. It provides a simple interface you can leverage via its Python module, which is included, by default, in the version of Python we use for this class Python 2.7.

SQLite can be installed by following this guide.

NOTE: The overarching system configuration concepts are explained in more detail in this guide, which we are using as our standard for setting up Flask apps in this course. For information regarding advanced system configuration (which you might need for some of the project extensions, if you tackle them), refer to that guide.

Organization

The following describes the initial file-structure of the directory ./src:

.
├── config.py
├── requirements.txt
├── run.py
├── test.py
└── todo
    ├── __init__.py
    ├── db.py
    ├── models.py
    └── routes.py

Below consists of brief discussions of each one of the above files:

• config.py defines the configuration for the Flask app to run with. You do not need to touch this file.
• requirements.txt outlines the initial module dependencies of the app. To install these, run pip install -r requirements.txt. If you pip install a module during the duration of your project, be sure to pip freeze > requirements.txt to add the new module to the requirements.txt file, or else we won't be able to run your project
• run.py is the run script for the Flask app. You do not need to touch this file.
• test.py is the test script for the Flask app. You will use this file to monitor your progress as you implement all the necessary functionality.
• todo/__init__.py defines the Flask app instance. You do not need to touch this file.
• todo/db.py defines a driver that reads and writes files as a form of persisting the data of your app. Read this file to get an idea of what functionalities it affords you and what you'll need to add to it. It outlines examples of how to perform basic storage operations. You should be writing basic storage operations to manipulate the data of your app.
• todo/models.py is where you should define the models of your application. All models should inherit from Model, which is the base class defining fundamental fields / functions required to store models as files.
• todo/routes.py defines all the routes (a.k.a. endpoints) that users will be able to interact with in order to create todo list items, delete todo list items, and list todo list items.

This initial framework is just a guideline to implementing the base features of the app. Feel free to change / reorganize at will. However, the expected functionality (listed below) stays the same.

Expected Functionality

In this project, we expect you to make an API that lets an application make requests to perform operations on todo list items called "tasks".

Essentially, the application is just keeping track of a series of tasks that a person has to do. Tasks should contain the following:

• A unique ID (see Model class that you should be extending from)
• A name
• A description
• A list of tags (like 'laundry', 'urgent', 'etc.')
• A time of creation
• A due date

You should write a model to represent this series of information called Task. In addition, you should write endpoints that allow for the following functionality:

Create a task

POST /tasks?name={name}&description={description}&tags={tags (comma separated)}&due_date={due date (in unix time)}

Creates a task with the following parameters. Testing is done via request.args in test.py. As such, you only need to ensure that all the tests pass in test.py to get full credit.

{
	"due_date": 1519328894,
	"description": "Need to jog",
	"tags": "run,jog,sprint",
	"created_at": 1519328894,
	"id": "3ab1a7e6-1833-11e8-af3d-9801a7a5b675",
	"name": "jogging"
}

List all tasks

GET /tasks

Get a list of all tasks

[{
	"due_date": 1519328894,
	"description": "Need to jog",
	"tags": "run,jog,sprint",
	"created_at": 1519328894,
	"id": "3ab1a7e6-1833-11e8-af3d-9801a7a5b675",
	"name": "jogging"
}]

Get task by ID

GET /tasks?id={id}

Get a task by its ID

[{
	"due_date": 1519328894,
	"description": "Need to jog",
	"tags": "run,jog,sprint",
	"created_at": 1519328894,
	"id": "3ab1a7e6-1833-11e8-af3d-9801a7a5b675",
	"name": "jogging"
}]

Delete a task

DELETE /tasks?id={id}

Delete a specific task

{
	"success": "true"
}

Delete all tasks

DELETE /tasks/all

Delete all tasks

{
	"success": "true"
}

Testing Your Code

We recommend testing your code using Flask Testing, or cURL-ing from the command line (although we prefer the tool httpie :)).

To make your lives easier we have provided you our test cases in the test.py file that you may leverage to test your endpoints. This file uses the unittest module extensively and can be extended if you wish to further develop your test suite to handle your own edge cases.

Extending the Assignment

You can extend this assignment in the following ways:

• Provide endpoints for updating any part of a specific task (name, description, tags, due date)
• Create a List model that own tasks (separate tasks into different todo lists). Create a CRUD interface for lists (Create, Read, Update, Delete) and modify the task creation endpoint to specify a list_id
• Add a front-end for utilizing your API (we recommend React, Angular, or jQuery for making AJAX requests to your API)
• Anything else you may like!

Project Submission

You should submit your project along with a readme.txt for your citations, project setup information, and any extensions you might have done. This should be at the root of your project (inside the src directory). Run the following to zip your project:

zip -r src.zip src -x src/venv\*

You can then submit this file to CMS.

Grading

You will be graded based on how many test cases you pass. Our test cases are provided for you in the test.py file.