Chapter 3: Software Design

3.1 Solution Design

3.1.1 Conceptual Design

The conceptual design represents the overall idea behind the project, breaking it down into features and components. The system aims to provide users with a platform where they can:

• Create an account

• Explore the system for additional information

• Access and update their profile

• Send messages to other users

• Post updates and comments

• Create groups and pages

To better visualize the concept, a Data Flow Diagram (DFD) has been designed. It shows how each feature interacts with the core database. Each feature is modeled individually to explain its functionality while also being integrated into a complete system view.

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3.1.2 Logical Design

The logical design focuses on the relationships and interactions between features and entities. We created an Entity Relationship Model (ERM) that clearly illustrates how each feature is logically connected to others.

For example:

• A User entity interacts with Posts, Comments, Images, Tags, and Likes.

• A Comment is associated with a specific Post, meaning a post must exist before it can be commented on.

The ERM also specifies the attributes of each entity and how they can be integrated logically.

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3.1.3 Physical Design

The physical design transforms conceptual and logical designs into practical implementation. Here, the entities and their relationships are translated into real database tables, including keys, constraints, and relational logic.

Figure 3.1: Entity Relationship Diagram (ERD)
Description: Shows all main entities and their mutual relationships.

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3.2 Entities and Attributes

Below are the main entities and their attributes represented in Figures 3.2.1 through 3.2.17:

1. User Entity (Fig 3.2.1)
   

   
   
   Attributes: user_id, firstName, lastName, email, password, gender, userSecurityQuestion, securityAnswer

2. Profile Entity (Fig 3.2.2)
   

   
   Attributes: user_id, ProfileImage, ProfileName, UserId

3. Permanent Address Entity (Fig 3.2.3)
   

   
   Attributes: PermanentAddress, UserId, HomePhoneNumber, OfficePhoneNumber, MobileNumber, HouseNumber, PostalCode, City, District, State, StreetNo

4. Current Address Entity (Fig 3.2.4)
   
   

   
   
   
   Attributes: currentAddressId, UserId, HomePhoneNumber, OfficePhoneNumber, MobileNumber, HouseNumber, PostalCode, City, District, State, Country, StreetNo

5. Experience Entity (Fig 3.2.5)
   

   
   
   
   Attributes: experienceId, UserId, jobTitle, jobField, jobDescription, joinDate, endDate, currentlyWork, company, companyDescription, status

6. User Education Entity (Fig 3.2.6)
   

   
   
   
   Attributes: educationId, userId, eduLevel, EduInstitute, startYear, endYear, BoardUniversity

7. User Friend Entity (Fig 3.2.7)
   

   
   
   
   Attributes: userfrdId, UserId, userFriendId, status, Time

8. Post Entity (Fig 3.2.8)
   

   
   
   
   Attributes: postId, userId, postText, postStatus, postDateAndTime, postImageId, GroupId, pageId

9. Comment Entity (Fig 3.2.9)
   

   
   
   
   Attributes: commId, postId, userId, commText, imageId, date_comm

10. Images Entity (Fig 3.2.10)
    

    
    
    
    Attributes: imgId, userId, imageName, DateName, dateUploaded, imgStatus

11. Like Entity (Fig 3.2.11)
    

    
    
    
    Attributes: likeId, postId, userId, imageId, dateTimeLiked

12. Groups Entity (Fig 3.2.12)
    
    
    Attributes: GroupId, UserId, GroupCategoryId, GroupName, Description, CreatedAt, Image, AdminStatus, Role, GroupStatus

13. GroupsCategory Entity (Fig 3.2.13)
    
    

    
    
    Attributes: GroupCategoryID, CategoryName, GroupCategoryIcon

14. UserGroupRelation Entity (Fig 3.2.14)
    

    
    
    
    Attributes: UserGroupRelationId, GroupID, UserID, JoinDateTime

15. Page Entity (Fig 3.2.15)
    

    
    
    Attributes: PageId, PageName, TimeLineImage, TimeLineImageCropped, Description, PageCategoryId, UserId, CreatedAt, LogoImage, LogoImageCropped

16. PageCategory Entity (Fig 3.2.16)
    

    
    
    Attributes: PageCategoryId, PageCategoryName, PageCategoryIcon

17. UserPageLikeRelation Entity (Fig 3.2.17)
    

    
    
    
    Attributes: UserPageLikeRelationId, LikeId, UserId, PageId

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3.3 Data Flow Diagram (DFD)

A Data Flow Diagram visually represents the flow of data through the system and how information is processed. DFDs are highly effective because they:

• Are easy for both technical and non-technical audiences to understand

• Provide a high-level system overview with clear boundaries and connections

• Detail system components and their interactions

DFDs consist of Entities, Processes, Data Stores, and Data Flows. They help demonstrate how input data is transformed into output results.

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3.3.1 Solution Architecture

Figure 3.3.1: Level 0 Data Flow Diagram

Description: Shows the broad system workflow. A user signs up, logs in, and accesses modules such as Profile, Posts, Groups, Friends, Messages, Likes, Pages, and Indicators.

Figure 3.3.2: Level 1 DFD for Account Creation

Description: The account creation process includes client-side and server-side validations, password encryption, and CAPTCHA for security.

Figure 3.3.3: Level 1 DFD for Groups and Pages

Description: Users can create groups and pages, and all data is stored in the corresponding database tables.

Figure 3.3.4: Level 1 DFD for Friends and Messaging

Description: Users can add friends, accept friend requests, and exchange messages with notifications for read/unread statuses.

Figure 3.3.5: Level 1 DFD for Posting and Commenting

Description: Users can post text or images, comment, and like posts. All actions are recorded in the database.

Figure 3.3.6: Level 2 DFD

Description: Combines all modules and shows relationships between them using directional arrows, representing the complete system workflow.

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