Class: CanCan::ModelAdapters::ActiveRecordAdapter

Inherits:
AbstractAdapter show all
Defined in:
lib/cancan/model_adapters/active_record_adapter.rb

Direct Known Subclasses

ActiveRecord4Adapter

Instance Attribute Summary collapse

Attributes inherited from AbstractAdapter

#model_class

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from AbstractAdapter

adapter_class, find, for_class?, inherited, matches_condition?, matches_conditions_hash?, override_condition_matching?, override_conditions_hash_matching?

Constructor Details

#initialize(model_class, rules) ⇒ ActiveRecordAdapter

Returns a new instance of ActiveRecordAdapter.



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# File 'lib/cancan/model_adapters/active_record_adapter.rb', line 19

def initialize(model_class, rules)
  super
  @compressed_rules = if CanCan.rules_compressor_enabled
                        RulesCompressor.new(@rules.reverse).rules_collapsed.reverse
                      else
                        @rules
                      end
  StiNormalizer.normalize(@compressed_rules)
  ConditionsNormalizer.normalize(model_class, @compressed_rules)
end

Instance Attribute Details

#compressed_rules ⇒ Object (readonly)

Returns the value of attribute compressed_rules.



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# File 'lib/cancan/model_adapters/active_record_adapter.rb', line 17

def compressed_rules
  @compressed_rules
end

Class Method Details

.child_association_to_parent(parent, child) ⇒ Object 



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# File 'lib/cancan/model_adapters/active_record_adapter.rb', line 74

def child_association_to_parent(parent, child)
  child_class = child.is_a?(Class) ? child : child.class
  parent_class = parent.is_a?(Class) ? parent : parent.class

  association = child_class.reflect_on_all_associations(:belongs_to).find do |belongs_to_assoc|
    # Do not match on polymorphic associations or it will throw an error (klass cannot be determined)
    !belongs_to_assoc.polymorphic? && belongs_to_assoc.klass == parent.class
  end

  return association if association

  parent_class.reflect_on_all_associations(:has_many).each do |has_many_assoc|
    association ||= matching_parent_child_polymorphic_association(has_many_assoc, child_class)
  end

  association
end

.matching_parent_child_polymorphic_association(parent_assoc, child_class) ⇒ Object 



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# File 'lib/cancan/model_adapters/active_record_adapter.rb', line 64

def matching_parent_child_polymorphic_association(parent_assoc, child_class)
  return nil unless parent_assoc.klass == child_class
  return nil if parent_assoc&.options[:as].nil?

  child_class.reflect_on_all_associations(:belongs_to).find do |child_assoc|
    # Only match this way for polymorphic associations
    child_assoc.polymorphic? && child_assoc.name == parent_assoc.options[:as]
  end
end

.nested_subject_matches_conditions?(parent, child, all_conditions) ⇒ Boolean

parent_id condition can be an array of integer or one integer, we check the parent against this

Returns:

  • (Boolean) 


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# File 'lib/cancan/model_adapters/active_record_adapter.rb', line 38

def nested_subject_matches_conditions?(parent, child, all_conditions)
  id_condition = parent_child_conditions(parent, child, all_conditions)
  return id_condition.include?(parent.id) if id_condition.is_a? Array
  return id_condition == parent.id if id_condition.is_a? Integer

  false
end

.override_nested_subject_conditions_matching?(parent, child, all_conditions) ⇒ Boolean

When belongs_to parent_id is a condition for a model, we want to check the parent when testing ability for a hash => model

Returns:

  • (Boolean) 


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# File 'lib/cancan/model_adapters/active_record_adapter.rb', line 33

def override_nested_subject_conditions_matching?(parent, child, all_conditions)
  parent_child_conditions(parent, child, all_conditions).present?
end

.parent_child_conditions(parent, child, all_conditions) ⇒ Object 



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# File 'lib/cancan/model_adapters/active_record_adapter.rb', line 46

def parent_child_conditions(parent, child, all_conditions)
  child_class = child.is_a?(Class) ? child : child.class
  parent_class = parent.is_a?(Class) ? parent : parent.class

  foreign_key = child_class.reflect_on_all_associations(:belongs_to).find do |association|
    # Do not match on polymorphic associations or it will throw an error (klass cannot be determined)
    !association.polymorphic? && association.klass == parent.class
  end&.foreign_key&.to_sym

  # Search again in case of polymorphic associations, this time matching on the :has_many side
  # via the :as option, as well as klass
  foreign_key ||= parent_class.reflect_on_all_associations(:has_many).find do |has_many_assoc|
    matching_parent_child_polymorphic_association(has_many_assoc, child_class)
  end&.foreign_key&.to_sym

  foreign_key.nil? ? nil : all_conditions[foreign_key]
end

.parent_condition_name(parent, child) ⇒ Object 



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# File 'lib/cancan/model_adapters/active_record_adapter.rb', line 92

def parent_condition_name(parent, child)
  child_association_to_parent(parent, child)&.name || parent.class.name.downcase.to_sym
end

.version_greater_or_equal?(version) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/cancan/model_adapters/active_record_adapter.rb', line 9

def self.version_greater_or_equal?(version)
  Gem::Version.new(ActiveRecord.version).release >= Gem::Version.new(version)
end

.version_lower?(version) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/cancan/model_adapters/active_record_adapter.rb', line 13

def self.version_lower?(version)
  Gem::Version.new(ActiveRecord.version).release < Gem::Version.new(version)
end

Instance Method Details

#build_relation(*where_conditions) ⇒ Object 



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# File 'lib/cancan/model_adapters/active_record_adapter.rb', line 138

def build_relation(*where_conditions)
  relation = @model_class.where(*where_conditions)
  return relation unless joins.present?

  # subclasses must implement `build_joins_relation`
  build_joins_relation(relation, *where_conditions)
end

#conditions ⇒ Object

Returns conditions intended to be used inside a database query. Normally you will not call this method directly, but instead go through ModelAdditions#accessible_by.

If there is only one “can” definition, a hash of conditions will be returned matching the one defined.

can :manage, User, :id => 1
query(:manage, User).conditions # => { :id => 1 }

If there are multiple “can” definitions, a SQL string will be returned to handle complex cases.

can :manage, User, :id => 1
can :manage, User, :manager_id => 1
cannot :manage, User, :self_managed => true
query(:manage, User).conditions # => "not (self_managed = 't') AND ((manager_id = 1) OR (id = 1))"



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# File 'lib/cancan/model_adapters/active_record_adapter.rb', line 112

def conditions
  conditions_extractor = ConditionsExtractor.new(@model_class)
  if @compressed_rules.size == 1 && @compressed_rules.first.base_behavior
    # Return the conditions directly if there's just one definition
    conditions_extractor.tableize_conditions(@compressed_rules.first.conditions).dup
  else
    extract_multiple_conditions(conditions_extractor, @compressed_rules)
  end
end

#database_records ⇒ Object 



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# File 'lib/cancan/model_adapters/active_record_adapter.rb', line 128

def database_records
  if override_scope
    @model_class.where(nil).merge(override_scope)
  elsif @model_class.respond_to?(:where) && @model_class.respond_to?(:joins)
    build_relation(conditions)
  else
    @model_class.all(conditions: conditions, joins: joins)
  end
end

#extract_multiple_conditions(conditions_extractor, rules) ⇒ Object 



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# File 'lib/cancan/model_adapters/active_record_adapter.rb', line 122

def extract_multiple_conditions(conditions_extractor, rules)
  rules.reverse.inject(false_sql) do |sql, rule|
    merge_conditions(sql, conditions_extractor.tableize_conditions(rule.conditions).dup, rule.base_behavior)
  end
end

#joins ⇒ Object

Returns the associations used in conditions for the :joins option of a search. See ModelAdditions#accessible_by



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# File 'lib/cancan/model_adapters/active_record_adapter.rb', line 148

def joins
  joins_hash = {}
  @compressed_rules.reverse_each do |rule|
    deep_merge(joins_hash, rule.associations_hash)
  end
  deep_clean(joins_hash) unless joins_hash.empty?
end