Components Overview

This document provides an overview of the components that make up Container1.
All components inside a container execute in the same process space. Aspects such as how components are packaged (e.g. one component vs many components per JAR file, DLL, shared library, etc) is an orthogonal concern.

Example: Internet Banking System Components

    C4Component
    title Component diagram for Internet Banking System - API Application

    Container(spa, "Single Page Application", "javascript and angular", "Provides all the internet banking functionality to customers via their web browser.")
    Container(ma, "Mobile App", "Xamarin", "Provides a limited subset to the internet banking functionality to customers via their mobile mobile device.")
    ContainerDb(db, "Database", "Relational Database Schema", "Stores user registration information, hashed authentication credentials, access logs, etc.")
    System_Ext(mbs, "Mainframe Banking System", "Stores all of the core banking information about customers, accounts, transactions, etc.")

    Container_Boundary(api, "API Application") {
        Component(sign, "Sign In Controller", "MVC Rest Controller", "Allows users to sign in to the internet banking system")
        Component(accounts, "Accounts Summary Controller", "MVC Rest Controller", "Provides customers with a summary of their bank accounts")
        Component(security, "Security Component", "Spring Bean", "Provides functionality related to singing in, changing passwords, etc.")
        Component(mbsfacade, "Mainframe Banking System Facade", "Spring Bean", "A facade onto the mainframe banking system.")

        Rel(sign, security, "Uses")
        Rel(accounts, mbsfacade, "Uses")
        Rel(security, db, "Read & write to", "JDBC")
        Rel(mbsfacade, mbs, "Uses", "XML/HTTPS")
    }

    Rel_Back(spa, sign, "Uses", "JSON/HTTPS")
    Rel(spa, accounts, "Uses", "JSON/HTTPS")

    Rel(ma, sign, "Uses", "JSON/HTTPS")
    Rel(ma, accounts, "Uses", "JSON/HTTPS")

    UpdateRelStyle(spa, sign, $offsetY="-40")
    UpdateRelStyle(spa, accounts, $offsetX="40", $offsetY="40")

    UpdateRelStyle(ma, sign, $offsetX="-90", $offsetY="40")
    UpdateRelStyle(ma, accounts, $offsetY="-40")

        UpdateRelStyle(sign, security, $offsetX="-160", $offsetY="10")
        UpdateRelStyle(accounts, mbsfacade, $offsetX="140", $offsetY="10")
        UpdateRelStyle(security, db, $offsetY="-40")
        UpdateRelStyle(mbsfacade, mbs, $offsetY="-40")