DEV Community: Alice

Software Development Diagrams - Class diagram

Alice — Sun, 01 Oct 2023 19:53:55 +0000

In this article, we will cover what a class diagram is, which are the key terms for using it, and in the end we will use the base exercise in order to create a class diagram.

A class diagram is a graphical representation that helps us understand the structure of a software application. Think of it as a visual guide that outlines what each part of the code does and how different parts relate to each other. It's an invaluable tool for planning and designing software systems, making it easier for developers to collaborate and build complex applications.

There are a lot of resources that cover all the details of a class diagram, so I will iterate throw the main components with a short explanation. I will recommend this website to learn more about class diagrams.

Here are the key components of a class diagram explained by a software developer:

Class: Think of it as a template for an object in your program.
Attributes (Variables): These are the characteristics or data that each object of a class will have.
Methods (Functions): Methods are the actions or behaviors that objects of a class can perform.
Associations: This shows how classes are connected or related to each other.
Aggregation: Aggregation is like saying one thing is made up of smaller parts. It's a way to show that a bigger thing, called the "whole," contains smaller things, called "parts," but the parts can exist on their own as well.
Inheritance (Generalization): Inheritance is like saying one class is a more specialized version of another.
Dependency: This is when one class relies on another class in some way, like when a class uses the methods or attributes of another class. It's like showing that one class needs another to work correctly.
Interfaces: An interface defines a set of methods that a class must implement. It's like setting a contract that says, "If you want to be this type of class, you have to do these things." It helps ensure consistency in your code.
Composition: A special type of aggregation where parts are destroyed when the whole is destroyed.
Package: Think of a package as a way to organize related classes. It's like putting classes that work together in a folder. Packages make it easier to manage large projects.

Now let’s create the class diagram for MyDoctor application. Having in mind the base exercises that we added in this article, we will create the class diagram for it. This diagram was created using LucidChart.

Reading this diagram we can see the classes with the main attributes and methods: User, Doctor, Patient, Office, Schedule, Appointment, BloodTest, Consultation, Surgery.

For the relationships we have the following:

Doctor and Patient inherits User since they are specialized users in the application
Doctor aggregates Schedule because the Doctor has a list of schedules
Office aggregates Schedule because the Office has a list of schedules
Patient aggregates Appointment because the Patient will have a list of schedules
BloodTest, Consultation and Surgery inherits Appointment
Appointment has a composition relationship with Schedule because an appointment cannot exist without a schedule

Tools for class diagrams: LucidChart, App Diagrams, Creately, Lucid, SmartDraw, Visual-Paradigm, Creately.

Class diagrams are a valuable tool for software developers because they provide a clear visual representation of the software's structure, making it easier to design, communicate, and understand complex systems. These components allow developers to define the building blocks of their software and the relationships between them.

Software Development Diagrams - Base Exercise

Alice — Sun, 01 Oct 2023 07:05:00 +0000

This exercise will be utilized in the upcoming articles to comprehend and apply the concepts using a real-life example.

The MyDoctor application aims to be a management tool for the appointments of a doctor.

A hospital has multiple offices.

The users of the application can be doctors and patients.

The doctors can apply to practice in offices and create a schedule for an office. The schedules in different offices can’t overlay.

📝 Example:
Doctor Ana is available in Office 4 on the 4th of September during 1 PM - 5PM.
Doctor Ana can’t practice in Office 5 on the 4th of September during 3PM - 8 PM, but she can practice in Office 5 on the 4th of September during 5:30PM - 8 PM.

The patients can see the existing doctors in the system, the schedule of the offices and can book appointments for specific doctors and for specific schedules. The appointments can be of 3 types:

Blood Test - 15 mins
Consultation - 30 mins
Surgery - 60 mins

The booking of an appointment will not be possible if another appointment is already booked at the same time frame. An email is sent to the patient with the confirmation of the appointment.

📝 Example:
Action 1: User Mike will create a blood test booking for Doctor Ana for the 4th of September starting with 15:30 PM → Possible
Action 2: User Mike will create an intervention booking for Doctor Ana for the 4th of September starting with 15:00 PM → Not Possible
Action 3: User Mike will create an intervention booking for Doctor Ana for the 4th of September starting with 16:00 PM → Possible

Software Development Diagrams - Introduction

Alice — Sun, 01 Oct 2023 07:00:00 +0000

In this article, we will start exploring the significance of diagrams, discuss the most important and commonly used types of diagrams, and list various online and offline tools for their creation.

In software development, we need tools that help us to understand systems, to create representations of ideas, and to plan the steps and the end result of a requirement. Diagrams are very useful in software development, whether you are in a management, functional, or technical position. There are a lot of types of diagrams, but in this article, we will cover the most useful and used diagrams.

Creating diagrams is quite easy, but there are some areas that need a little bit of attention, like the name of the component, the interaction and relationships between components. This is especially because you need someone that looks for the very first time on the diagram that you created, to understand what you needed to explain with it. So diagrams are like a unified language, and we need to learn to speak it.

The most used diagrams from my point of view are:

Class diagram
Sequence diagram
Flow diagram
Use-case diagram
Database Relationship Diagram
C4 diagrams: Container diagram, Context diagram, Component diagram, Class diagram

Let’s get one by one to understand them.

Class diagram - is a diagram that contains the attributes and the operations of a class. It defines the relationships between classes and the constraints of their interaction. This kind of diagram is usually used to model an object-oriented system.

Sequence diagram - shows process interactions in sequence between components in the form of messages exchanged between the processes and objects needed to carry out the functionality.

Flow diagram - is like a visual map or picture that shows how things move or happen in a process. It uses shapes and arrows to illustrate the order and connections between steps or actions. It's a handy tool for understanding and explaining how something works, especially in things like computer programs or complex systems.

Use-case diagram - a use-case diagram is like a picture or chart that shows how people or things interact with a system or software. It's a way to understand what a system does from a user's perspective. Use-case diagrams help designers and developers figure out what a system needs to do to meet the needs of its users.

Database Relationship diagram - is a visual map that shows how different pieces of information in a database are connected to each other. It uses lines and symbols to illustrate how data in one part of the database relates to data in another part. It helps people understand how different tables or collections of data are linked together, making it easier to manage and retrieve information from the database.

C4 diagrams - short for "Context, Container, Component, and Code" diagrams, are a set of visual representations used in software architecture to describe and document different aspects of a software system's structure and components. C4 diagrams are valuable for both high-level architectural discussions and low-level technical documentation. They help teams communicate effectively about a software system's design, enabling better understanding and decision-making throughout the development process.

Tools

There are multiple applications to create diagrams. I will mention the ones that I used and I think they are very useful: App Diagrams, IcePanel, Creately, dbdiagram.io, Lucid, Diagramming, Canva, SmartDraw, Visual-Paradigm, Creately, Figma, Miro.

Many articles and documents talk about this topic and explain various diagram types and how to use them. In this series of articles, my main focus will be to walk you through all these diagrams and provide essential insights. Additionally, we'll practice using a base exercise, which you can find in the next article.

Please leave a comment with your most used diagram or with the tool that you use when creating diagrams.

Thank you!

eOffice - Collaboration through microservices using Redis

Alice — Mon, 29 Aug 2022 20:00:31 +0000

Overview
Submission Category
Video
Link to the application
Link to code
Architecture
How the data is stored
Functionalities

Overview of My Submission

eOffice is human resources platform that provides processes to onboard a new employee and to manage the benefits of the employees distributing the responsibilities between the different rolls.

Submission Category

The submission category is Microservices Mavens using for communication between services the pubSub feature from Redis.

Video

Architecture & Technologies

Link to the application

The application is hosted in Azure.
Link to the application

Link to Code

AlexandraFolvaiter / e-office

e-office | Redis Hackathon on Dev

Link to the application

Overview video

Project description

eOffice is human resources platform that provides processes to onboard a new employee and to manage the benefits of the employees distributing the responsibilities between the different rolls.

Functionalities

See all onboardings
Create an onboarding
See details of an onboarding
See all system accounts requests
Resolve a system account request

Architecture and technologies

Presentation project: Server Blazor Application using .Net 6.0
Microservices: Web API using .Net 6.0
Databases: SQL Server
Microservices communication: Redis pub/sub

Flow diagrams:

Create the onboarding
Resolve a system account request

How to run it locally?

Prerequisites

.Net 6.0
3 SQL server databases
A redis database

Local installation

Add the connection strings in the appsettings.josn for each module for the databases
Set as startup projects: eOffice, eOffice.Onboardings.API, eOffice.Leave.API, eOffice.SystemAccounts.API
Run the projects

How it works

How the data is

…

View on GitHub

Architecture

Presentation project: Server Blazor Application using .Net 6.0
Microservices: Web API using .Net 6.0
Databases: SQL Server
Microservices communication: Redis pub/sub

Language Used

C# - .Net 6.0

Flow diagrams

Create the onboarding
Resolve a system account request

How the data is stored

The microservices are communicating with each other using the pub/sub from Redis, for each type of communication a different channel will be used.
3 channels

SystemAccount_Channel
- Publisher: Onboardings Module
- Subscriber: SystemAccounts Module
Leave_Channel
- Publisher: Onboardings Module
- Subscriber: LeaveBalance Module
Onboarding_Channel
- Publisher: SystemAccounts Module, LeaveBalance Module
- Subscriber: Onboardings Module

Publis code

var modelAsString = JsonConvert.SerializeObject(model);
_pubSub.Publish("channel_name", modelAsString);

Subscribe code

connection.GetSubscriber()
    .Subscribe("channel_name", (channel, message) =>
    {
        // DO something
    });

Functionalities

Dashboard

See all onboardings

Create an onboarding

See details of an onboarding

See all system accounts requests

Resolve a system account request

Check out Redis OM, client libraries for working with Redis as a multi-model database.
Use RedisInsight to visualize your data in Redis.
Sign up for a free Redis database.

SmartGoals - Building a reliable application with Azure Services

Alice — Mon, 28 Feb 2022 21:53:29 +0000

Motivation
Overview of My Submission
Functionalities
Infrastructure Architecture & Technologies
Link to Code on GitHub

Motivation

SmartGoals project was created to participate in the Microsoft Azure Trial Hackathon and to show the process of integrating an application in the Azure ecosystem.

Overview of My Submission

The main idea on which this project is created can be found in this file.

SmartGoals aims to do the management of the goals and objectives that a person has, giving the opportunity to be accessible anywhere by any device. The user can update them as often as needed, keeping the progress and having an overview of the next steps that he has to make in order to complete the goal.

Submission Category

SmartGoals is participating to Microsoft Azure Trial Hackathon in Computing Captains category.

Functionalities

A user can:

View all goals
Add a new goal
Edit an existing goal
Remove an existing goal
View the details of a goal
View all the objectives
Add a new objective
Edit an existing objective
Remove an existing objective

The functional demo can be found here:

Infrastructure Architecture and Technologies

The application is based on 3 components:

A Client - Is an Angular application deployed on a Azure App Service. It allows users to see and manipulate the goals and objectives using a friendly UI.
An API - Is an .Net 6.0 Azure Function deployed on a Azure Function App. It exposes an API with CRUD operations to manipulate the goals and the objectives.
A Database - Is a Azure SQL Database which stores the data.

The demo for the infrastructure can be found here:

Link to Code on GitHub

The code of the project was added on GitHub. Please check it out to see more details.

AlexandraFolvaiter / smart-goals

Motivation

SmartGoals project was created to participate in the Microsoft Azure Trial Hackathon and to show the process of integrating an application in the Azure ecosystem.

Project description

The main idea on which this project is created can be found in this file.

The project aims to do the management of the goals and objectives that a person has, giving the opportunity to be accessible anywhere by any device. The user can update them as often as needed, keeping the progress and having an overview of the next steps that he has to make in order to complete the goal.

Infrastructure Architecture & Technologies

The application is based on 3 components:

A Client - Is an Angular application deployed on a Azure App Service. It allows users to see and manipulate the goals and objectives using…

View on GitHub

For the next 30 days, the application can be found here and the API can be accessed here.

DEV Community: Alice

Software Development Diagrams - Class diagram

Software Development Diagrams - Base Exercise

Software Development Diagrams - Introduction

Tools

eOffice - Collaboration through microservices using Redis

Table of contents

Overview of My Submission

Submission Category

Video

Architecture & Technologies

Link to the application

Link to Code

AlexandraFolvaiter / e-office

Architecture

Language Used

Flow diagrams

How the data is stored

Functionalities

SmartGoals - Building a reliable application with Azure Services

Table of Contents

Motivation

Overview of My Submission

Submission Category

Functionalities

Infrastructure Architecture and Technologies

Link to Code on GitHub

AlexandraFolvaiter / smart-goals

Table of Contents

Motivation

Project description

Infrastructure Architecture & Technologies