Module: Mermaid::ElementRenderers::ERDRelationshipRenderer

Defined in:
lib/mermaid/element_renderers/erd_relationship_renderer.rb

Overview

Module containing Mermaid rendering logic for Diagrams::ElementRenderers::ERDRelationship

Constant Summary collapse

CARDINALITY_MAP =

Maps cardinality symbols from Diagrams::ElementRenderers::ERDRelationship::CARDINALITY to Mermaid syntax (using right-side convention).

{
  ZERO_OR_ONE: 'o|',
  ONE_ONLY: '||',
  ZERO_OR_MORE: 'o{', # Corrected based on Mermaid docs
  ONE_OR_MORE: '|{' # Corrected based on Mermaid docs
}.freeze

Instance Method Summary collapse

Instance Method Details

#to_mermaid_fragment ⇒ String

Generates the Mermaid fragment for this relationship.

Returns:

  • (String) —

    The Mermaid syntax fragment for the relationship.



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# File 'lib/mermaid/element_renderers/erd_relationship_renderer.rb', line 18

def to_mermaid_fragment
  # Fetch symbols, raise error if invalid key (shouldn't happen if Diagrams gem validates)
  left_symbol_raw = CARDINALITY_MAP.fetch(cardinality1)
  right_symbol = CARDINALITY_MAP.fetch(cardinality2)

  # Generate the left symbol by mirroring the right-side convention
  left_symbol = case left_symbol_raw
                when 'o{' then '}o' # Mirror zero or more
                when '|{' then '}|' # Mirror one or more
                else left_symbol_raw.reverse # Simple reverse for |o and ||
                end

  # Always use '--' based on user feedback for compatibility
  id_symbol = '--'

  fragment = "\"#{entity1}\" "
  fragment << left_symbol  # e.g., |o
  fragment << id_symbol    # e.g., --
  fragment << right_symbol # e.g., }|
  fragment << " \"#{entity2}\""
  fragment << " : \"#{label}\"" if label && !label.strip.empty?
  fragment << "\n"
  fragment
end