Class: Diagrams::ERDiagram

Inherits:
Base
  • Object
show all
Defined in:
lib/diagrams/er_diagram.rb

Overview

Represents an Entity Relationship Diagram (ERD).

Instance Attribute Summary collapse

Attributes inherited from Base

#checksum, #version

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Base

#diff, from_hash, from_json, #to_h, #to_json

Constructor Details

#initialize(entities: [], relationships: [], version: 1) ⇒ ERDiagram

Initializes a new ERDiagram.

Parameters:

  • entities (Array<Element::ERDEntity>) (defaults to: []) —

    Initial entities (optional).

  • relationships (Array<Element::ERDRelationship>) (defaults to: []) —

    Initial relationships (optional).

  • version (String, Integer, nil) (defaults to: 1) —

    User-defined version identifier.



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# File 'lib/diagrams/er_diagram.rb', line 13

def initialize(entities: [], relationships: [], version: 1)
  super(version:)
  @entities = Array(entities).each_with_object({}) { |e, h| h[e.name] = e }
  @relationships = Array(relationships)
  validate_relationships!
  update_checksum!
end

Instance Attribute Details

#entities ⇒ Object (readonly)

Returns the value of attribute entities.



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# File 'lib/diagrams/er_diagram.rb', line 6

def entities
  @entities
end

#relationships ⇒ Object (readonly)

Returns the value of attribute relationships.



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# File 'lib/diagrams/er_diagram.rb', line 6

def relationships
  @relationships
end

Class Method Details

.from_h(data_hash, version:, checksum:) ⇒ Object 



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# File 'lib/diagrams/er_diagram.rb', line 93

def self.from_h(data_hash, version:, checksum:)
  entities_data = data_hash[:entities] || data_hash['entities'] || []
  relationships_data = data_hash[:relationships] || data_hash['relationships'] || []

  entities = entities_data.map do |entity_h|
    entity_data = entity_h.transform_keys(&:to_sym)
    attributes_data = entity_data[:entity_attributes] || entity_data[:attributes] || [] # Accept both old and new key for now
    attributes = attributes_data.map do |attr_h|
      attr_data = attr_h.transform_keys(&:to_sym)
      # Convert keys back to symbols if they are strings
      # Convert keys back to symbols
      attr_data[:keys] = attr_data[:keys].map(&:to_sym) if attr_data[:keys].is_a?(Array)
      Elements::ERDAttribute.new(attr_data)
    end
    # Use the correct attribute name when creating the entity
    Elements::ERDEntity.new(entity_data.merge(entity_attributes: attributes))
  end

  relationships = relationships_data.map do |rel_h|
    rel_data = rel_h.transform_keys(&:to_sym)
    # Convert cardinalities back to symbols if they are strings
    rel_data[:cardinality1] = rel_data[:cardinality1].to_sym if rel_data[:cardinality1].is_a?(String)
    rel_data[:cardinality2] = rel_data[:cardinality2].to_sym if rel_data[:cardinality2].is_a?(String)
    Elements::ERDRelationship.new(rel_data)
  end

  diagram = new(entities:, relationships:, version:)

  # Optional: Verify checksum
  if checksum && diagram.checksum != checksum
    warn "Checksum mismatch for loaded ERDiagram (version: #{version}). Expected #{checksum}, got #{diagram.checksum}."
  end

  diagram
end

Instance Method Details

#add_entity(name:, attributes: []) ⇒ Elements::ERDEntity

Adds an entity to the diagram.

Parameters:

  • name (String) —

    The unique name of the entity.

  • attributes (Array<Hash>) (defaults to: []) —

    Array of attribute definitions (hashes like { type:, name:, keys:, comment: }).

Returns:

Raises:

  • (ArgumentError) —

    if an entity with the same name already exists.



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# File 'lib/diagrams/er_diagram.rb', line 27

def add_entity(name:, attributes: [])
  raise ArgumentError, "Entity name '#{name}' cannot be empty" if name.nil? || name.strip.empty?
  raise ArgumentError, "Entity with name '#{name}' already exists" if @entities.key?(name)

  entity_attributes = attributes.map do |attr_hash|
    Elements::ERDAttribute.new(attr_hash.transform_keys(&:to_sym))
  end
  new_entity = Elements::ERDEntity.new(name:, entity_attributes: entity_attributes) # Use renamed attribute

  @entities[name] = new_entity
  update_checksum!
  new_entity
end

#add_relationship(entity1:, entity2:, cardinality1:, cardinality2:, identifying: false, label: nil) ⇒ Elements::ERDRelationship

Adds a relationship between two entities.

Parameters:

  • entity1 (String) —

    Name of the first entity.

  • entity2 (String) —

    Name of the second entity.

  • cardinality1 (Symbol) —

    Cardinality of entity1 relative to entity2 (e.g., :ONE_ONLY).

  • cardinality2 (Symbol) —

    Cardinality of entity2 relative to entity1 (e.g., :ZERO_OR_MORE).

  • identifying (Boolean) (defaults to: false) —

    Whether the relationship is identifying (default: false).

  • label (String, nil) (defaults to: nil) —

    Optional label describing the relationship action.

Returns:

Raises:

  • (ArgumentError) —

    if either entity does not exist.



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# File 'lib/diagrams/er_diagram.rb', line 51

def add_relationship(entity1:, entity2:, cardinality1:, cardinality2:, identifying: false, label: nil)
  unless @entities.key?(entity1) && @entities.key?(entity2)
    raise ArgumentError, "One or both entities ('#{entity1}', '#{entity2}') not found for relationship."
  end

  new_relationship = Elements::ERDRelationship.new(
    entity1:,
    entity2:,
    cardinality1:,
    cardinality2:,
    identifying:,
    label:
  )
  @relationships << new_relationship
  update_checksum!
  new_relationship
end

#find_entity(entity_name) ⇒ Elements::ERDEntity?

Finds an entity by its name.

Parameters:

  • entity_name (String) —

    The name of the entity to find.

Returns:



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# File 'lib/diagrams/er_diagram.rb', line 73

def find_entity(entity_name)
  @entities[entity_name]
end

#identifiable_elements ⇒ Object 



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# File 'lib/diagrams/er_diagram.rb', line 86

def identifiable_elements
  {
    entities: @entities.values,
    relationships: @relationships # Relationships don't have a simple unique ID, rely on object equality for diff
  }
end

#to_h_content ⇒ Object

— Base Class Implementation —



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# File 'lib/diagrams/er_diagram.rb', line 79

def to_h_content
  {
    entities: @entities.values.map(&:to_h),
    relationships: @relationships.map(&:to_h)
  }
end