Class: MermaidRailsErd::RelationshipBuilders::HasAndBelongsToManyRelationshipBuilder

Inherits:
BaseRelationshipBuilder show all
Defined in:
lib/mermaid_rails_erd/relationship_builders/habtm_relationship_builder.rb

Instance Attribute Summary

Attributes inherited from BaseRelationshipBuilder

#association_resolver, #model_data_collector, #symbol_mapper

Instance Method Summary collapse

Constructor Details

#initialize(symbol_mapper:, association_resolver:, printed_tables: Set.new, model_data_collector: nil) ⇒ HasAndBelongsToManyRelationshipBuilder 



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# File 'lib/mermaid_rails_erd/relationship_builders/habtm_relationship_builder.rb', line 9

def initialize(symbol_mapper:, association_resolver:, printed_tables: Set.new, model_data_collector: nil)
  super(symbol_mapper: symbol_mapper, association_resolver: association_resolver, model_data_collector: model_data_collector)
  @printed_tables = printed_tables
end

Instance Method Details

#build(model, assoc) ⇒ Object 



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# File 'lib/mermaid_rails_erd/relationship_builders/habtm_relationship_builder.rb', line 14

def build(model, assoc)
  from_table = model.table_name
  to_table_info = resolve_association_model(model, assoc)

  return log_missing_table_warning(model, assoc, "target model does not exist") unless to_table_info

  join_table = assoc.join_table.to_s

  # Check if we need to verify the table existence
  unless @printed_tables.include?(join_table)
    begin
      ActiveRecord::Base.connection.columns(join_table)
      @printed_tables << join_table
    rescue StandardError => e
      return log_missing_table_warning(model, assoc, "join table #{join_table} is missing: #{e.message}")
    end
  end

  # Try to get the foreign keys
  source_fk = nil
  target_fk = nil

  begin
    source_fk = assoc.foreign_key
  rescue StandardError => e
    puts "  WARNING: Could not determine foreign key for #{model.name} in HABTM: #{e.message}"
    register_invalid_association(model, assoc, "Could not determine foreign key: #{e.message}")
  end

  begin
    target_fk = assoc.association_foreign_key
  rescue StandardError => e
    puts "  WARNING: Could not determine association foreign key for #{model.name}##{assoc.name}: #{e.message}"
    register_invalid_association(model, assoc, "Could not determine association foreign key: #{e.message}")
  end

  # Skip if we couldn't determine both foreign keys
  return log_missing_table_warning(model, assoc, "could not determine foreign keys") if !source_fk || !target_fk

  # If we reach here, the join table exists, so create relationships
  [
    Relationship.new(
      join_table,
      from_table,
      source_fk,
      "}o--||",
      nil, # Let the Relationship generate the label
      join_table, # fk_table
      source_fk, # fk_column
      from_table, # pk_table
      model.primary_key, # pk_column
    ),
    Relationship.new(
      join_table,
      to_table_info[:table_name],
      target_fk,
      "}o--||",
      nil, # Let the Relationship generate the label
      join_table, # fk_table
      target_fk, # fk_column
      to_table_info[:table_name], # pk_table
      to_table_info[:primary_key], # pk_column
    ),
  ]
end