Views

LikeC4 is model-based, and views are projections of the model from various perspectives, scopes, and levels of detail, such as:

System/service overviews
Component interactions in specific use cases
Data flows and sequence diagrams

LikeC4 does not enforce specific rules, such as a strict number of levels or what should be included; it’s entirely up to you and your context.

View definition

Views are defined in views section.
They can be named (must be unique) or unnamed (can’t be referenced, but still can be exported):

views {
  // with name
  view index {
  }
  // unnamed
  view {
  }
}

The view’s name is used as an image filename during export and as part of the URL when sharing, so it’s advisable to define one.

View properties

Views can have a title, description, tags and links:

views {

  view epic12 {
    #next, #epic-12
    title "Cloud System - Changes in Epic-12"

    // Description can be Markdown with triple quotes
    description """
      This diagram shows the **high-level**
      components and interactions.
    """

    link https://my.jira/epic/12 'Epic-12'

  }

}

Properties must be defined before predicates.

Scoped views

A view can be defined for a specific element (view of ..).
The view will then inherit the scope of that element:

views {

  view {
    include api // ⛔️ Error: 'api' is not found
  }

  view of cloud.backend {
    include api // ✅ This is OK, resolves to 'cloud.backend.api'
  }

  view of legacy {
    include api // ✅ This is OK, resolves to 'legacy.api'
  }

}

Additionally, a scoped view becomes the default for the element:

views {

  view {
    // on click navigates to 'view1',
    // because it is default for 'cloud.backend'
    include cloud.backend
  }

  view view1 of cloud.backend {
    include *
  }

}

You can define multiple views for the same element, with the default determined by their order.

Extend views

Views can be extended to avoid duplication, to create a “baseline” or, for example, “slides” for a presentation:

views {

  view view1 {
    include *
  }

  view view2 extends view1 {
    title 'Same as View1, but with more details'

    style * {
      color muted
    }

    include some.backend
  }

  // cascade inheritance
  view view3 extends view2 {
    title 'Same as View2, but with more details'

    include * -> some.backend
  }

}

The predicates and style rules of extended views applied after the ones from ancestors.

Extended view also inherits the scope:

views {

  view view1 of cloud.backend {
    title 'Backend components'
  }

  view view2 extends view1 {
    include api // ✅ This is OK, references 'cloud.backend.api'
  }

}