Examples

Welcome to the Ruleur examples section. Here you'll find practical, real-world examples of using Ruleur to solve common business logic problems.

Featured Examples

Permission Rules

Implement role-based access control and complex permission logic.

Use Cases:

• Role-based access control (RBAC)
• Resource ownership checks
• Hierarchical permissions
• Feature flags and entitlements

Workflow Automation

Build approval workflows and state machine logic.

Use Cases:

• Document approval workflows
• Order processing pipelines
• Multi-step validation flows
• State transitions

Dynamic Pricing

Calculate prices, discounts, and fees based on business rules.

Use Cases:

• Tiered pricing models
• Dynamic discounts
• Shipping cost calculation
• Promotional rules

Real-World Cases

Complete examples from production systems.

Use Cases:

• E-commerce order validation
• SaaS feature access
• Insurance policy evaluation
• Content moderation

Quick Examples

Simple Permission Check

engine = Ruleur.define do
  rule 'admin_access' do
    conditions do
      all?(user(:admin?))
    end

    actions do
      set :access, true
    end
  end

  rule 'owner_update' do
    conditions do
      all?(user(:owner?, record))
    end

    actions do
      set :update, true
    end
  end
end

result = engine.run(user: current_user, record: @post)
can_update = result[:update] # => true or nil

Discount Calculation

engine = Ruleur.define do
  rule 'bulk_discount', salience: 10 do
    match { all?(order(:total).gt?(500)) }

    actions { set :discount, 0.15 }
  end

  rule 'vip_discount', salience: 20 do
    match { all?(customer(:vip?)) }

    actions { set :discount, 0.20 }
  end
end

result = engine.run(order: order, customer: customer)
discount = result[:discount] # Higher salience wins

Workflow State Transition

engine = Ruleur.define do
  rule 'can_submit' do
    conditions do
      all?(
        document(:draft?),
        document(:complete?),
        not?(document(:submitted?))
      )
    end

    actions do
      set :submit, true
    end
  end

  rule 'can_approve' do
    conditions do
      all?(
        user(:approver?),
        document(:submitted?),
        not?(document(:approved?))
      )
    end

    actions do
      set :approve, true
    end
  end
end

Example Patterns

Fact Checking Pattern

Check conditions and set result flags:

rule 'validation' do
  conditions do
    all?(
      user(:authenticated?),
      user(:email_verified?),
      not?(user(:banned?))
    )
  end

  actions { set :user_valid, true }
end

Calculation Pattern

Compute values based on inputs:

rule 'calculate_total' do
  conditions do
    all?(order(:items).present)
  end

  actions do
    order = context[:order]
    subtotal = order.items.sum(&:price)
    tax = subtotal * 0.08
    shipping = calculate_shipping(order)

    set :subtotal, subtotal
    set :tax, tax
    set :shipping, shipping
    set :total, subtotal + tax + shipping
  end
end

Chaining Pattern

Rules that depend on other rules' results:

rule 'step1' do
  match { all?(input(:valid?)) }

  actions { set :step1_complete, true }
end

rule 'step2' do
  conditions do
    all?(
      flag(:step1_complete),
      input(:ready?)
    )
  end

  actions { set :step2_complete, true }
end

Loading Examples

All examples are available in the repository:

git clone https://github.com/tagliala/ruleur.git
cd ruleur/examples

Try It Yourself

Each example includes:

• Complete working code
• Test cases
• YAML versions
• Variations and alternatives

Need Help?

• Check the Guide for concepts
• See the API Reference for details
• Join discussions on GitHub

Contributing Examples

Have a great example? We'd love to include it! See our Contributing Guide.