Branching and paths¶

Clipboard icons

Commands and prompts on this page use fenced blocks with a copy button (top-right). Click to copy the full text for Terminal, Claude, or Cursor.

LXPack supports non-linear courses with variables and flow rules (v0.2+). If you omit flow, learners move through lessons in list order.

Variables¶

Declare defaults in course.yaml:

variables:
  track:
    default: basic
    type: string

HTML interactions can change variables (advanced):

if (window.parent.lxpack) {
  window.parent.lxpack.setVariable('track', 'advanced');
}

Flow rules¶

Each rule has when (condition) and goto (activity id). Optional from limits when the rule runs:

flow:
  - from: choose_path
    when:
      variable:
        eq: [track, advanced]
    goto: advanced_lab
  - from: choose_path
    when:
      variable:
        eq: [track, basic]
    goto: wrap_up
  - from: final_quiz
    when:
      assessment:
        passed: final_quiz
    goto: wrap_up

Field	Meaning
`from`	Activity id the learner is on when this rule is evaluated (recommended for `variable.eq`)
`when`	Condition that must be true
`goto`	Next activity id when the rule matches

Condition	Meaning
`variable.eq: [name, value]`	Variable equals value
`assessment.passed: <id>`	Learner passed that quiz
`interaction.done: <lesson_id>`	HTML or SPA lesson tracked completion
`all: [...]` / `any: [...]`	Combine conditions

interaction.done and assessment.passed rules infer from when omitted. variable.eq rules without from apply on every navigation (validator warns).

Full example¶

Study examples/branching-demo/ in the repository:

interactions/choose-path sets the path
component lesson for advanced track
Quiz gate before wrap-up

cd examples/branching-demo

cd examples/branching-demo
lxpack preview

Validate carefully¶

lxpack validate

lxpack validate

Errors often mean:

goto points to a lesson id that does not exist
interaction.done references a lesson that is not html or spa
Flow graph has impossible cycles (validator reports cycles)

Authoring tip¶

Sketch the flow on paper first. Name every lesson id before writing flow. Use Claude with the branching section of Prompts for Claude.

SCORM note¶

SCORM 2004 multi-SCO packages map activities to separate launch pages. Start with SCORM 1.2 while learning branching, unless your LMS requires 2004.