Class: RailsERD::Diagram::Mermaid

Inherits:
Diagram
  • Object
show all
Defined in:
lib/rails_erd/diagram/mermaid.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#graph ⇒ Object

Returns the value of attribute graph.



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# File 'lib/rails_erd/diagram/mermaid.rb', line 11

def graph
  @graph
end

Instance Method Details

#arrow_body(relationship) ⇒ Object 



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# File 'lib/rails_erd/diagram/mermaid.rb', line 185

def arrow_body(relationship)
  relationship.indirect? ? ".." : "--"
end

#arrow_head(relationship) ⇒ Object 



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# File 'lib/rails_erd/diagram/mermaid.rb', line 189

def arrow_head(relationship)
  relationship.to_many? ?  ">" : ""
end

#arrow_tail(relationship) ⇒ Object 



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# File 'lib/rails_erd/diagram/mermaid.rb', line 193

def arrow_tail(relationship)
  relationship.many_to? ? "<" : ""
end

#attribute_key_marker(attr) ⇒ Object 



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# File 'lib/rails_erd/diagram/mermaid.rb', line 169

def attribute_key_marker(attr)
  markers = []
  markers << "PK" if attr.primary_key?
  markers << "FK" if attr.foreign_key?
  markers.empty? ? "" : " #{markers.join(',')}"
end

#build_class_diagram_entity(short_name, full_name, attributes) ⇒ Object

Build entity lines for classDiagram mode (used in clustering)



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# File 'lib/rails_erd/diagram/mermaid.rb', line 198

def build_class_diagram_entity(short_name, full_name, attributes)
  lines = ["\t\tclass `#{short_name}`"]
  attributes.each do |attr|
    lines << "\t\t`#{short_name}` : +#{attr.type} #{attr.name}"
  end
  lines
end

#diagram_type ⇒ Object 



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# File 'lib/rails_erd/diagram/mermaid.rb', line 107

def diagram_type
  er_diagram? ? "erDiagram" : "classDiagram"
end

#draw_relation(from, to, relationship) ⇒ Object

Mermaid renders any entity a relationship names, so an edge to an entity that was filtered out would draw it back into the diagram. Skip those, as Graphviz already does.



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# File 'lib/rails_erd/diagram/mermaid.rb', line 117

def draw_relation(from, to, relationship)
  return unless entity_drawn?(from.name) && entity_drawn?(to.name)

  graph << if er_diagram?
             "\t#{quote_entity_name(from.name)} #{er_relation_notation(relationship)} #{quote_entity_name(to.name)} : \"\""
           else
             "\t`#{from.name}` #{relation_arrow(relationship)} `#{to.name}`"
           end
end

#emit_clustered_entities ⇒ Object

Emit entities grouped by namespace for clustering



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# File 'lib/rails_erd/diagram/mermaid.rb', line 207

def emit_clustered_entities
  # Entities without namespace go first (outside any namespace block)
  @entities_by_namespace[""].each do |entity_lines|
    entity_lines.each { |line| graph << line.sub(/^\t\t/, "\t") }
  end

  # Then emit each namespace block
  @entities_by_namespace.each do |ns, entity_blocks|
    next if ns == ""

    # Convert Ruby namespace (Admin::Users) to Mermaid format (Admin.Users)
    mermaid_ns = ns.gsub("::", ".")
    graph << "\tnamespace #{mermaid_ns} {"
    entity_blocks.each do |entity_lines|
      entity_lines.each { |line| graph << line }
    end
    graph << "\t}"
  end
end

#entity_drawn?(name) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rails_erd/diagram/mermaid.rb', line 127

def entity_drawn?(name)
  @drawn_entity_names.include?(name.to_s)
end

#er_diagram? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rails_erd/diagram/mermaid.rb', line 111

def er_diagram?
  options[:mermaid_style] == :erdiagram || options[:mermaid_style] == :er
end

#er_relation_notation(relationship) ⇒ Object

erDiagram relationship notation using crow's foot Format: left_cardinality--right_cardinality Cardinality markers:

|| = exactly one
o| = zero or one
}| = one or more
}o = zero or more


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# File 'lib/rails_erd/diagram/mermaid.rb', line 149

def er_relation_notation(relationship)
  line = relationship.indirect? ? ".." : "--"

  # Left side (source cardinality - how many source entities relate to one destination)
  left = if relationship.many_to?
    relationship.source_optional? ? "o{" : "|{"
  else
    relationship.source_optional? ? "o|" : "||"
  end

  # Right side (destination cardinality - how many destination entities relate to one source)
  right = if relationship.to_many?
    relationship.destination_optional? ? "}o" : "}|"
  else
    relationship.destination_optional? ? "|o" : "||"
  end

  "#{left}#{line}#{right}"
end

#filename ⇒ Object 



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# File 'lib/rails_erd/diagram/mermaid.rb', line 103

def filename
  "#{options.filename}.mmd"
end

#quote_entity_name(name) ⇒ Object

Quote entity names that contain special characters (like

for namespaces)

Mermaid erDiagram requires double quotes for names with special characters



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# File 'lib/rails_erd/diagram/mermaid.rb', line 133

def quote_entity_name(name)
  name = name.to_s
  if name.include?("::")
    %("#{name}")
  else
    name
  end
end

#relation_arrow(relationship) ⇒ Object

classDiagram relationship arrows (legacy)



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# File 'lib/rails_erd/diagram/mermaid.rb', line 177

def relation_arrow(relationship)
  arrow_body = arrow_body relationship
  arrow_head = arrow_head relationship
  arrow_tail = arrow_tail relationship

  "#{arrow_tail}#{arrow_body}#{arrow_head}"
end