Imported from majiayu000/claude-skill-registry-data (development/plutonium-definition/SKILL.md). Install upstream with npx skills add majiayu000/claude-skill-registry-data --skill plutonium-definition. Copyright stays with the author.

Definition Fields

Configure how fields are rendered using field, input, display, and column declarations.

Core Methods

Basic Usage

class PostDefinition < ResourceDefinition
  # field - changes type everywhere
  field :content, as: :markdown

  # input - form-specific
  input :title,
    label: "Article Title",
    hint: "Enter a descriptive title",
    placeholder: "e.g. Getting Started"

  # display - show page specific
  display :content,
    as: :markdown,
    description: "Published content",
    wrapper: {class: "col-span-full"}

  # column - table specific
  column :title, label: "Article", align: :center
  column :view_count, align: :end
end

Available Field Types

Input Types (Forms)

Display Types (Show/Index)

:string, :text, :email, :url, :phone, :markdown, :number, :integer, :decimal, :boolean, :date, :time, :datetime, :association, :attachment

Field Options

Field-Level Options (wrapper)

input :title,
  label: "Custom Label",           # Custom label text
  hint: "Help text for forms",     # Form help text
  placeholder: "Enter value",      # Input placeholder
  description: "For displays"      # Display description

Tag-Level Options (HTML element)

input :title,
  class: "custom-class",           # CSS class
  data: {controller: "custom"},    # Data attributes
  required: true,                  # HTML required
  readonly: true,                  # HTML readonly
  disabled: true                   # HTML disabled

Wrapper Options

display :content, wrapper: {class: "col-span-full"}
input :notes, wrapper: {class: "bg-gray-50"}

Select/Choices

Static Choices

input :category, as: :select, choices: %w[Tech Business Lifestyle]
input :status, as: :select, choices: Post.statuses.keys

Dynamic Choices (requires block)

# Basic dynamic
input :author do |f|
  choices = User.active.pluck(:name, :id)
  f.select_tag choices: choices
end

# With context access
input :team_members do |f|
  choices = current_user.organization.users.pluck(:name, :id)
  f.select_tag choices: choices
end

# Based on object state
input :related_posts do |f|
  choices = if object.persisted?
    Post.where.not(id: object.id).published.pluck(:title, :id)
  else
    []
  end
  f.select_tag choices: choices
end

Conditional Rendering

class PostDefinition < ResourceDefinition
  # Show based on object state
  display :published_at, condition: -> { object.published? }
  display :rejection_reason, condition: -> { object.rejected? }

  # Show based on environment
  field :debug_info, condition: -> { Rails.env.development? }
end

Note: Use condition for UI state logic. Use policies for authorization.

Dynamic Forms (pre_submit)

Use pre_submit: true to create forms that dynamically show/hide fields based on other field values. When a pre_submit field changes, the form re-renders server-side and conditions are re-evaluated.

Basic Pattern

class PostDefinition < ResourceDefinition
  # Trigger field - causes form to re-render on change
  input :send_notifications, pre_submit: true

  # Dependent field - only shown when condition is true
  input :notification_channel,
    as: :select,
    choices: %w[Email SMS],
    condition: -> { object.send_notifications? }
end

How It Works

1. User changes a pre_submit: true field
2. Form submits via Turbo (no page reload)
3. Server re-renders the form with updated object state
4. Fields with condition procs are re-evaluated
5. Newly visible fields appear, hidden fields disappear

Multiple Dependent Fields

class QuestionDefinition < ResourceDefinition
  # Primary selector
  input :question_type, as: :select,
    choices: %w[text choice scale date boolean],
    pre_submit: true

  # Conditional fields based on question_type
  input :max_length,
    as: :integer,
    condition: -> { object.question_type == "text" }

  input :choices,
    as: :text,
    hint: "One choice per line",
    condition: -> { object.question_type == "choice" }

  input :min_value,
    as: :integer,
    condition: -> { object.question_type == "scale" }

  input :max_value,
    as: :integer,
    condition: -> { object.question_type == "scale" }
end

Cascading Dependencies

class PropertyDefinition < ResourceDefinition
  # First level
  input :property_type, as: :select,
    choices: %w[residential commercial],
    pre_submit: true

  # Second level - depends on property_type
  input :residential_type, as: :select,
    choices: %w[apartment house condo],
    condition: -> { object.property_type == "residential" },
    pre_submit: true

  input :commercial_type, as: :select,
    choices: %w[office retail warehouse],
    condition: -> { object.property_type == "commercial" },
    pre_submit: true

  # Third level - depends on residential_type
  input :apartment_floor,
    as: :integer,
    condition: -> { object.residential_type == "apartment" }
end

Dynamic Choices with pre_submit

Combine pre_submit with block-based dynamic choices:

class SurveyResponseDefinition < ResourceDefinition
  input :category, as: :select,
    choices: Category.pluck(:name, :id),
    pre_submit: true

  # Choices change based on selected category
  input :subcategory do |f|
    choices = if object.category.present?
      Category.find(object.category).subcategories.pluck(:name, :id)
    else
      []
    end
    f.select_tag choices: choices
  end
end

Tips

• Only add pre_submit: true to fields that control visibility of other fields
• Keep dependencies simple - deeply nested conditions are hard to debug
• The form submits on change, so avoid pre_submit on frequently-changed fields

Custom Rendering

Block Syntax

For Display (can return any component):

display :status do |field|
  StatusBadgeComponent.new(value: field.value, class: field.dom.css_class)
end

display :metrics do |field|
  if field.value.present?
    MetricsChartComponent.new(data: field.value)
  else
    EmptyStateComponent.new(message: "No metrics")
  end
end

For Input (must use form builder methods):

input :birth_date do |f|
  case object.age_category
  when 'adult'
    f.date_tag(min: 18.years.ago.to_date)
  when 'minor'
    f.date_tag(max: 18.years.ago.to_date)
  else
    f.date_tag
  end
end

phlexi_tag (Advanced Display)

# With component class
display :status, as: :phlexi_tag, with: StatusBadgeComponent

# With inline proc
display :priority, as: :phlexi_tag, with: ->(value, attrs) {
  case value
  when 'high'
    span(class: "badge badge-danger") { "High" }
  when 'medium'
    span(class: "badge badge-warning") { "Medium" }
  else
    span(class: "badge badge-info") { "Low" }
  end
}

Custom Component Class

input :color_picker, as: ColorPickerComponent
display :chart, as: ChartComponent

Column Options

Alignment

column :title, align: :start    # Left (default)
column :status, align: :center  # Center
column :amount, align: :end     # Right

Value Formatting

Use formatter for simple value transformations without a full block:

# Truncate long text
column :description, formatter: ->(value) { value&.truncate(30) }

# Format numbers
column :price, formatter: ->(value) { "$%.2f" % value if value }

# Transform values
column :status, formatter: ->(value) { value&.humanize&.upcase }

The formatter option:

• Receives the field value as its argument
• Returns the transformed value for display
• Works with column and display declarations
• Is simpler than block syntax when you only need to transform the value

formatter vs block: Use formatter when you only need the value. Use a block when you need access to the full record:

# formatter - receives just the value
column :name, formatter: ->(value) { value&.titleize }

# block - receives the full record
column :full_name do |record|
  "#{record.first_name} #{record.last_name}"
end

Custom Column Rendering

Use a block to customize how a column value is displayed. The block receives the raw record:

column :price do |record|
  "$#{"%.2f" % record.price}" if record.price
end

column :status do |record|
  case record.status
  when 'active' then "✓ Active"
  when 'pending' then "⏳ Pending"
  else record.status.humanize
  end
end

column :description do |record|
  record.description&.truncate(50)
end

column :author do |record|
  record.author&.name || "Unknown"
end

Nested Inputs

Render inline forms for associated records. Requires accepts_nested_attributes_for on the model.

Model Setup

class Post < ResourceRecord
  has_many :comments
  has_one :metadata

  accepts_nested_attributes_for :comments, allow_destroy: true, limit: 10
  accepts_nested_attributes_for :metadata, update_only: true
end

Basic Declaration

class PostDefinition < ResourceDefinition
  # Block syntax
  nested_input :comments do |n|
    n.input :body, as: :text
    n.input :author_name
  end

  # Using another definition
  nested_input :metadata, using: PostMetadataDefinition, fields: %i[seo_title seo_description]
end

Options

nested_input :amenities,
  allow_destroy: true,
  limit: 20,
  description: "Add property amenities" do |n|
    n.input :name
    n.input :icon, as: :select, choices: ICONS
  end

Singular Associations

For has_one and belongs_to, limit is automatically 1:

nested_input :profile do |n|  # has_one
  n.input :bio
  n.input :website
end

Conditional Nested Inputs

nested_input :shipping_address,
  condition: -> { object.requires_shipping? } do |n|
    n.input :street
    n.input :city
  end

How It Works

1. Renders a template (hidden) for new records
2. Renders fieldsets for existing records
3. Stimulus controller handles Add/Remove
4. _destroy checkbox marks records for deletion
5. Parameters submitted as model[association_attributes][id][field]

Gotchas

• Model must have accepts_nested_attributes_for
• For custom class names, use class_name: in both model and using: in definition
• update_only: true hides the Add button
• Limit is enforced in UI (Add button hidden when reached)

File Uploads

input :avatar, as: :file
input :avatar, as: :uppy

input :documents, as: :file, multiple: true
input :documents, as: :uppy,
  allowed_file_types: ['.pdf', '.doc'],
  max_file_size: 5.megabytes

Common Patterns

Rich Text Content

field :content, as: :markdown    # Form: rich editor
display :content, as: :markdown   # Show: rendered markdown

Money Fields

input :price, as: :decimal, class: "font-mono"
display :price, class: "font-bold text-green-600"

Status Badges

display :status do |field|
  color = case field.value
  when 'active' then 'green'
  when 'pending' then 'yellow'
  else 'gray'
  end
  span(class: "badge badge-#{color}") { field.value.humanize }
end

Hidden Fields

field :author_id, as: :hidden
input :tenant_id, as: :hidden

Context in Blocks

Inside condition procs and input blocks:

• object - The record being edited/displayed
• current_user - The authenticated user
• current_parent - Parent record for nested resources
• request, params - Request information
• All helper methods

Related Skills

• plutonium-definition - Overview and structure
• plutonium-definition-actions - Actions and interactions
• plutonium-definition-query - Search, filters, scopes
• plutonium-forms - Custom form templates and field builders
• plutonium-views - Custom page and display templates