Advanced Content Routing Patterns

Once you have mastered the basic switch for routing, you can combine conditions and use more advanced brokers to create sophisticated routing logic.

Pattern 1: Multi-Condition Routing

A check can evaluate multiple conditions. For example, route a message with CRITICAL severity and an EU region label to a separately named priority output.

Multi-Condition Check

output:
  switch:
    cases:
      - check: 'this.severity == "CRITICAL" && this.region == "EU"'
        output:
          # Separate high-priority destination for the authored EU label
          file:
            path: /tmp/eu-critical-alerts.jsonl
            codec: lines

      # Other cases follow...
      - check: 'this.region == "EU"'
        output:
          file:
            path: /tmp/eu-data.jsonl
            codec: lines

      - check: 'this.severity == "CRITICAL"'
        output:
          file:
            path: /tmp/critical.jsonl
            codec: lines

The order is important. The multi-condition check must come first, otherwise the single-condition checks would match the event first.

Pattern 2: Multi-Criteria Scoring

For complex logic, calculate a priority_score in a mapping processor first, then use the switch to route based on that score.

The Priority Queues tutorial uses the same pattern for multi-criteria routing.

Processor:

- mapping: |
    root = this
    let score = 0
    if this.severity == "CRITICAL" { score = score + 50 }
    if this.region == "EU" { score = score + 30 }
    if this.event_type == "payment" { score = score + 20 }
    root.priority_score = score

Output:

output:
  switch:
    cases:
      - check: this.priority_score >= 80 # e.g., CRITICAL EU payment
        output:
          # highest priority destination

      - check: this.priority_score >= 50 # e.g., CRITICAL non-EU
        output:
          # medium priority destination

      # ... and so on

This pattern makes your routing logic much easier to read, manage, and test.