Use cases

This document describes several use cases for the BacPack System. Some of these use cases are described further in Usage.

Package Context Management

This section describes use cases related to managing a Package Context. After adding and updating a Package, the Package should be built, which is described in Build a Package from Package Context use case.

Add Package

After adding a Package Config to Package Context, the Package can be built by Packager and hosted in a Package Repository. The Package can then be easily added to Projects by including it in CMakeLists.

sequenceDiagram
  actor User
  participant Packager
  participant Package Repository
  participant Package Context
  participant Package Tracker
  participant Project

  User->>Package Context: Adds Package definition
  User->>Packager: Build Package

Update Package

Updating a Package means changing the Package Config in Package Context and then rebuilding the Package. Changing the version tag also requires removing the old version Package from the Package Repository before building the new version.

sequenceDiagram
  actor User
  participant Packager
  participant Package Repository
  participant Package Context
  participant Package Tracker
  participant Project

  User->>Package Context: Updates Package definition
  opt if version tag changed
    User->>Package Repository: Remove old Package
  end
  User->>Packager: Build Package

Remove Package

Removing a Package from Package Context means removing the Package Config from Package Context and then removing the Package from the Package Repository.

sequenceDiagram
  actor User
  participant Packager
  participant Package Repository
  participant Package Context
  participant Package Tracker
  participant Project

  User->>Package Context: Remove Package definition
  User->>Package Repository: Remove Package

Build a Package from Package Context

The Packager is used to build Packages/Apps from Package Context. The built Packages are then uploaded to a Package Repository. The Packages in Package Context form dependency trees, therefore Packager supports several ways how to build the Packages: - build single Package - build single Package with its dependencies - build all Packages which depends on a Package - build all Packages in Package Context

These use cases are described in detail in Packager documentation.

sequenceDiagram
  actor User
  participant Packager
  participant Package Repository
  participant Package Context
  participant Package Tracker
  participant Project

  User->>Packager: Initiates Package build
  Package Context->>Packager: Retrieves Package definitions
  Packager->>Packager: Package build
  Packager->>Package Repository: Uploads built Packages

Use already built Packages in Project

To use a Package that was built with Packager and uploaded to a Package Repository, use Package Tracker macros to add this Package to the application. The Package Tracker repository URL must also be set in CMLibStorage.cmake in the root directory of the application.

sequenceDiagram
  actor User
  participant Packager
  participant Package Repository
  participant Package Context
  participant Package Tracker
  participant Project

  User->>Project: Puts link of Package Tracker
  User->>Project: Adds desired Package to CMakeLists
  User->>Project: Initiates Project build
  rect
    Note right of Package Repository: Project build
    Project->>Package Tracker: Asks for Packages
    Package Repository->>Package Tracker: Retrieves Packages
    Package Tracker->>Project: Adds Packages to build
    Project->>Project: FIND_PACKAGE<br>for each Package
    Project->>Project: Project build
  end