Assignment 3 COMPSCI 235 – SOFTWARE DEVELOPMENT METHODOLOGIES • The objective of this assignment is to modify/extend the web application concerned with a collection of books in a library, such that instead of a memory repository, we now use a SQLite database to persist data. – This assignment builds on Assignment 2, so you need a working version of your Library application in order to extend it further. – Please get into contact with us by mail if you don’t have a working version of A2. • All the features that you implemented in Assignment 2 should now be switched to work with a database instead of an in-memory repository. Brief 2 • At this stage you should have a running web application that allows you to e.g. browse books, login users, write book reviews, …, served by the memory repository. • Now we will replace the data stored in memory with a “simple” file based SQLite database. • This can still be seen as an initial development step, compared to a dedicated external database server e.g. running MySQL, or Oracle. Our application 3 Our application 4 Flask Request handlers Service layer Domain model Abstract repository interface Database repository Memory repository SQL database Internal dependency External dependency Repository pattern Interface Implementation Our application 5 Flask Request handlers Service layer Domain model Abstract repository interface Database repository Memory repository SQL database Internal dependency External dependency Repository pattern Interface Implementation Database component to add How to go from memory-based storage to persistent database? We will use Python SQLAlchemy. The required steps are: 1. Include a database engine and do the setup and configuration to initialize the database connection and to allow communication. 2. Create the object relational mapper that connects our domain model with the relational database. 3. Write code that populates our database with data from external (e.g. json) files. 4. Write the SqlAlchemyRepository class, derived from AbstractRepository, to enable the communication with the application through the service layer. 5. Write test cases for the database aspects of the application. Assignment 3 6 Make an update of our provided COVID-19 web application from here: https://github.com/martinurschler/2021CompSci235-03-CovidWebApp using ‘git pull’ or clone it if you haven’t yet done so. • We have added a new branch ‘SQLite_Database_Repo’ • You can have a look at the local branches using ‘git branch’ (note that ‘git branch –a’ shows local and remote branches) and you can switch to this branch using ‘git checkout SQLite_Database_Repo’ • This new branch implements the SQLite based database repository for the COVID application. Assignment 3 7 • This assignment will lead to a total of 12% of marks. • Grading requirements: – The web application works with at least the same features as in Assignment 2, but now using the persistent storage in a database. Therefore, the information displayed on the web page has to be fetched from the database. If applicable, users and reviews also have to be persisted in the database. We will inspect the app and the database file when marking! – There are tests available that demonstrate the functioning of the database similar to the memory based web application. Grading 8 9C grade B grade A grade A+ grade % range 50 - 65 66 - 80 81 - 90 91 - 100 Functional requirements • Browsing books • Displaying/searching books based on authors, release years, publishers • Registering, logging in/logging out users • Reviewing books • A new cool feature Non-functional requirements • Conformance to established project structure • Effective use of HTML, CSS and Jinja • Appropriate use of HTTP • Application of Repository pattern • Unit and integration testing of your developed code! • Use of Blueprints • Use of authentication techniques • Use of HTML forms / WTForms • Cool feature design report Same grade ranges as in Assignment 2 will apply (see next slide for clarification). • If you submitted a C/B range application for Assignment 2, and if you transfer the same features using a database, you will qualify for a C/B range grade in Assignment 3. • If you already submitted a A/A+ range application for Assignment 2, and if you transfer the same features using a database, you will qualify for an A/A+ range grade in Assignment 3. • Additionally, there’s an opportunity to extend solely the database features to reach a higher grade for Assignment 3. For example, if you had previously submitted a B grade application for Assignment 2, you could add a cool new feature now just for the database version to secure an A grade for Assignment 3. And in this case, you may also include a report for A+. Grading 10 We would highly encourage you (and this is in your own benefit) to work in your original group as formed for A2, since A3 is a continuation of what was produced for A2. In exceptional circumstances, where there were issues in the group dynamics, you may choose to work alone or recreate your team. In this case you have to get into contact with the teaching team. Group Marking Criteria - Similar to A2, each member of the group/team will submit a confidential allocation of percentage of work done by them and their groupmate through a Google Form which will be published later. Group work 11 • Submission: – Please continue using your existing team repositories from Assignment 2 for submitting Assignment 3. Please get into contact with the teaching team if you have an exceptional reason to change teams. • When assessing your work, markers will expect to: – Find a readme file in the project’s root directory that explains how to set up a virtual environment and install any dependencies via a requirements.txt file – Run the application by typing ‘flask run’, from within the virtual environment in a terminal window – Run all tests by typing ‘python –m pytest test_folder’, from within the virtual environment in a terminal window • Submissions are due Friday, 15 October 2021 at 23:59 hrs (Late submission penalties similar to A2 will apply). Submission and due date 12 • Similar advice as for Assignment 2 should be followed. • Use test-driven development. • Study the material of labs from week 8 and especially week 9. Make heavy use of the COVID-19 application and. You can use code from there as freely as you want. • We will also provide a recording of a help tutorial similar to Assignment 2. • Use external resources to supplement lecture materials – SQLAlchemy https://www.sqlalchemy.org/ • Don’t hack, take a disciplined approach to developing software – Use pen and paper to sketch out your design and to think it through before coding, put these things into your personal journal (which will not be marked). Advice 13