Class: Rhales::ViewComposition

Inherits:
Object
  • Object
show all
Includes:
Utils::LoggingHelpers
Defined in:
lib/rhales/core/view_composition.rb

Overview

ViewComposition builds and represents the complete template dependency graph for a view render. It provides a data-agnostic, immutable representation of all templates (layout, view, partials) required for rendering.

This class is a key component in the two-pass rendering architecture, enabling server-side data aggregation before HTML generation.

Responsibilities: - Dependency Resolution: Recursively discovers and loads all partials - Structural Representation: Organizes templates into a traversable tree - Traversal Interface: Provides methods to iterate templates in render order

Key Characteristics: - Data-Agnostic: Knows nothing about runtime context or request data - Immutable: Once created, the composition is read-only - Cacheable: Can be cached in production for performance

Defined Under Namespace

Classes: CircularDependencyError, TemplateNotFoundError

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Utils::LoggingHelpers

#format_value, #log_timed_operation, #log_with_metadata

Methods included from Utils

#now, #now_in_μs, #pretty_path

Constructor Details

#initialize(root_template_name, loader:, config: nil) ⇒ ViewComposition

Returns a new instance of ViewComposition.



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# File 'lib/rhales/core/view_composition.rb', line 35

def initialize(root_template_name, loader:, config: nil)
  @root_template_name = root_template_name
  @loader             = loader
  @config             = config
  @templates          = {}
  @dependencies       = {}
  @loading            = Set.new
end

Instance Attribute Details

#dependencies ⇒ Object (readonly)

Returns the value of attribute dependencies.



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# File 'lib/rhales/core/view_composition.rb', line 33

def dependencies
  @dependencies
end

#root_template_name ⇒ Object (readonly)

Returns the value of attribute root_template_name.



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# File 'lib/rhales/core/view_composition.rb', line 33

def root_template_name
  @root_template_name
end

#templates ⇒ Object (readonly)

Returns the value of attribute templates.



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# File 'lib/rhales/core/view_composition.rb', line 33

def templates
  @templates
end

Instance Method Details

#dependencies_of(template_name) ⇒ Object

Get direct dependencies of a template



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# File 'lib/rhales/core/view_composition.rb', line 101

def dependencies_of(template_name)
  @dependencies[template_name] || []
end

#each_document_in_render_order ⇒ Object

Iterate through all documents in render order Layout -> View -> Partials (depth-first)



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# File 'lib/rhales/core/view_composition.rb', line 67

def each_document_in_render_order(&)
  return enum_for(:each_document_in_render_order) unless block_given?

  visited = Set.new

  # Process layout first if specified
  root_doc = @templates[@root_template_name]
  if root_doc && root_doc.layout
    layout_name = root_doc.layout
    if @templates[layout_name]
      yield_template_recursive(layout_name, visited, &)
    end
  end

  # Then process the root template and its dependencies
  yield_template_recursive(@root_template_name, visited, &)
end

#extract_partials(parser) ⇒ Object (private) 



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# File 'lib/rhales/core/view_composition.rb', line 198

def extract_partials(parser)
  partials         = Set.new
  template_content = parser.section('template')

  return partials unless template_content

  # Extract partial references from template
  # Looking for {{> partial_name}} patterns
  template_content.scan(/\{\{>\s*([^\s}]+)\s*\}\}/) do |match|
    partials.add(match[0])
  end

  partials
end

#freeze_composition ⇒ Object (private) 



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# File 'lib/rhales/core/view_composition.rb', line 229

def freeze_composition
  @templates.freeze
  @dependencies.freeze
  @templates.each_value(&:freeze)
  @dependencies.each_value(&:freeze)
  freeze
end

#layout ⇒ Object

Get the layout for the root template (if any)



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# File 'lib/rhales/core/view_composition.rb', line 106

def layout
  root_template = @templates[@root_template_name]
  return nil unless root_template

  root_template.layout
end

#load_template_recursive(template_name, parent_path = nil) ⇒ Object (private) 



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# File 'lib/rhales/core/view_composition.rb', line 115

def load_template_recursive(template_name, parent_path = nil)
  depth = @loading.size

  # Check for circular dependencies
  if @loading.include?(template_name)
    log_with_metadata(Rhales.logger, :error, 'Circular dependency detected',
      template: template_name,
      dependency_chain: @loading.to_a,
      depth: depth
    )
    raise CircularDependencyError, "Circular dependency detected: #{template_name} -> #{@loading.to_a.join(' -> ')}"
  end

  # Skip if already loaded (cache hit)
  if @templates.key?(template_name)
    Rhales.logger.debug("Template cache hit: template=#{template_name}")
    return
  end

  @loading.add(template_name)

  begin
    # Load template using the provided loader
    start_time = now_in_μs
    parser = @loader.call(template_name)
    load_duration = now_in_μs - start_time

    unless parser
      log_with_metadata(Rhales.logger, :error, 'Template not found',
        template: template_name,
        parent: parent_path,
        depth: depth,
        search_duration: load_duration
      )
      raise TemplateNotFoundError, "Template not found: #{template_name}"
    end

    # Store the template
    @templates[template_name]    = parser
    @dependencies[template_name] = []

    # Extract and load partials
    partials = extract_partials(parser)

    if partials.any?
      log_with_metadata(Rhales.logger, :debug, 'Resolved partial',
        template: template_name,
        partials_found: partials,
        partial_count: partials.size,
        depth: depth,
        load_duration: load_duration
      )
    end

    partials.each do |partial_name|
      @dependencies[template_name] << partial_name
      load_template_recursive(partial_name, template_name)
    end

    # Load layout if specified and not already loaded
    if parser.layout && !@templates.key?(parser.layout)
      log_with_metadata(Rhales.logger, :debug, 'Layout resolution',
        template: template_name,
        layout: parser.layout,
        depth: depth
      )
      load_template_recursive(parser.layout, template_name)
    end

    # Log successful template load
    log_with_metadata(Rhales.logger, :debug, 'Template loaded',
      template: template_name,
      parent: parent_path,
      depth: depth,
      has_partials: partials.any?,
      has_layout: !parser.layout.nil?,
      load_duration: load_duration
    )
  ensure
    @loading.delete(template_name)
  end
end

#resolve! ⇒ Object

Resolve all template dependencies



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# File 'lib/rhales/core/view_composition.rb', line 45

def resolve!
  log_timed_operation(Rhales.logger, :debug, 'Template dependency resolution',
    root_template: @root_template_name
  ) do
    load_template_recursive(@root_template_name)
    freeze_composition

    # Log resolution results
    log_with_metadata(Rhales.logger, :debug, 'Template composition resolved',
      root_template: @root_template_name,
      total_templates: @templates.size,
      total_dependencies: @dependencies.values.sum(&:size),
      partials: @dependencies.values.flatten.uniq,
      layout: layout
    )

    self
  end
end

#template(name) ⇒ Object

Get a specific template by name



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# File 'lib/rhales/core/view_composition.rb', line 86

def template(name)
  @templates[name]
end

#template?(name) ⇒ Boolean

Check if a template exists in the composition

Returns:

  • (Boolean) 


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# File 'lib/rhales/core/view_composition.rb', line 91

def template?(name)
  @templates.key?(name)
end

#template_names ⇒ Object

Get all template names



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# File 'lib/rhales/core/view_composition.rb', line 96

def template_names
  @templates.keys
end

#yield_template_recursive(template_name, visited) ⇒ Object (private) 



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# File 'lib/rhales/core/view_composition.rb', line 213

def yield_template_recursive(template_name, visited, &)
  return if visited.include?(template_name)

  visited.add(template_name)

  # First yield dependencies (partials)
  (@dependencies[template_name] || []).each do |dep_name|
    yield_template_recursive(dep_name, visited, &)
  end

  # Then yield the template itself
  if @templates[template_name]
    yield template_name, @templates[template_name]
  end
end