Module: Squeel::Adapters::ActiveRecord::Relation
- Defined in:
- lib/squeel/adapters/active_record/relation.rb,
lib/squeel/adapters/active_record/3.0/relation.rb
Constant Summary collapse
- JoinAssociation =
::ActiveRecord::Associations::ClassMethods::JoinDependency::JoinAssociation
- JoinDependency =
::ActiveRecord::Associations::ClassMethods::JoinDependency
Instance Attribute Summary collapse
-
#join_dependency ⇒ Object
Returns a JoinDependency for the current relation.
Class Method Summary collapse
-
.included(base) ⇒ Object
ZOMG ALIAS_METHOD_CHAIN IS BELOW.
Instance Method Summary collapse
- #attribute_visitor ⇒ Object
-
#attrs_to_orderings(order) ⇒ Object
reverse_sql_order will reverse the order of strings or Orderings, but not attributes.
- #build_arel ⇒ Object
- #build_join_dependency(relation, joins) ⇒ Object
- #build_where(opts, other = []) ⇒ Object
- #collapse_wheres(arel, wheres) ⇒ Object
-
#debug_sql ⇒ Object
Simulate the logic that occurs in #to_a.
- #eager_load(*args) ⇒ Object
- #find_equality_predicates(nodes) ⇒ Object
- #group(*args) ⇒ Object
- #having(*args) ⇒ Object
- #includes(*args) ⇒ Object
- #joins(*args) ⇒ Object
-
#merge(r) ⇒ Object
We need to be able to support merging two relations that have a different base class.
- #order(*args) ⇒ Object
- #predicate_visitor ⇒ Object
- #preload(*args) ⇒ Object
- #prepare_relation_for_association_merge!(r, association_name) ⇒ Object
- #relation_with_different_base?(r) ⇒ Boolean
- #reorder(*args) ⇒ Object
- #select(value = Proc.new) ⇒ Object
- #visit! ⇒ Object
- #where(opts = Proc.new, *rest) ⇒ Object
- #where_values_hash_with_squeel ⇒ Object
Instance Attribute Details
#join_dependency ⇒ Object
Returns a JoinDependency for the current relation.
We don’t need to clear out @join_dependency by overriding #reset, because the default #reset already does this, despite never setting it anywhere that I can find. Serendipity, I say!
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# File 'lib/squeel/adapters/active_record/relation.rb', line 19 def join_dependency @join_dependency ||= (build_join_dependency(table.from(table), @joins_values) && @join_dependency) end |
Class Method Details
.included(base) ⇒ Object
ZOMG ALIAS_METHOD_CHAIN IS BELOW. HIDE YOUR EYES! … … … Since you’re still looking, let me explain this horrible transgression you see before you. You see, Relation#where_values_hash is defined on the ActiveRecord::Relation class. Since it’s defined there, but I would very much like to modify its behavior, I have three choices.
-
Inherit from ActiveRecord::Relation in a Squeel::Relation class, and make an attempt to usurp all of the various calls to methods on ActiveRecord::Relation by doing some really evil stuff with constant reassignment, all for the sake of being able to use super().
-
Submit a patch to Rails core, breaking this method off into another module, all for my own selfish desire to use super() while mucking about in Rails internals.
-
Use alias_method_chain, and say 10 hail Hanssons as penance.
I opted to go with #3. Except for the hail Hansson thing. Unless you’re DHH, in which case, I totally said them.
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# File 'lib/squeel/adapters/active_record/relation.rb', line 345 def self.included(base) base.class_eval do alias_method_chain :where_values_hash, :squeel end end |
Instance Method Details
#attribute_visitor ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 29 def attribute_visitor Visitors::AttributeVisitor.new( Context.new(join_dependency) ) end |
#attrs_to_orderings(order) ⇒ Object
reverse_sql_order will reverse the order of strings or Orderings, but not attributes
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# File 'lib/squeel/adapters/active_record/relation.rb', line 114 def attrs_to_orderings(order) order.map do |o| Arel::Attribute === o ? o.asc : o end end |
#build_arel ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 82 def build_arel arel = table.from table build_join_dependency(arel, @joins_values) unless @joins_values.empty? predicate_viz = predicate_visitor attribute_viz = attribute_visitor collapse_wheres(arel, predicate_viz.accept((@where_values - ['']).uniq)) arel.having(*predicate_viz.accept(@having_values.uniq.reject{|h| h.blank?})) unless @having_values.empty? arel.take(connection.sanitize_limit(@limit_value)) if @limit_value arel.skip(@offset_value) if @offset_value arel.group(*attribute_viz.accept(@group_values.uniq.reject{|g| g.blank?})) unless @group_values.empty? order = @reorder_value ? @reorder_value : @order_values order = attribute_viz.accept(order.uniq.reject{|o| o.blank?}) order = reverse_sql_order(attrs_to_orderings(order)) if @reverse_order_value arel.order(*order) unless order.empty? build_select(arel, attribute_viz.accept(@select_values.uniq)) arel.from(@from_value) if @from_value arel.lock(@lock_value) if @lock_value arel end |
#build_join_dependency(relation, joins) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 120 def build_join_dependency(manager, joins) buckets = joins.group_by do |join| case join when String 'string_join' when Hash, Symbol, Array, Nodes::Stub, Nodes::Join, Nodes::KeyPath 'association_join' when JoinAssociation 'stashed_join' when Arel::Nodes::Join 'join_node' else raise 'unknown class: %s' % join.class.name end end association_joins = buckets['association_join'] || [] stashed_association_joins = buckets['stashed_join'] || [] join_nodes = buckets['join_node'] || [] string_joins = (buckets['string_join'] || []).map { |x| x.strip }.uniq join_list = custom_join_ast(manager, string_joins) # All of this duplication just to add self.join_dependency = JoinDependency.new( @klass, association_joins, join_list ) join_nodes.each do |join| join_dependency.alias_tracker.aliased_name_for(join.left.name.downcase) end join_dependency.graft(*stashed_association_joins) @implicit_readonly = true unless association_joins.empty? && stashed_association_joins.empty? join_dependency.join_associations.each do |association| association.join_to(manager) end manager.join_sources.concat join_nodes.uniq manager.join_sources.concat join_list manager end |
#build_where(opts, other = []) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 256 def build_where(opts, other = []) case opts when String, Array super else # Let's prevent PredicateBuilder from doing its thing [opts, *other].map do |arg| case arg when Array # Just in case there's an array in there somewhere @klass.send(:sanitize_sql, arg) when Hash @klass.send(:expand_hash_conditions_for_aggregates, arg) else arg end end end end |
#collapse_wheres(arel, wheres) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 274 def collapse_wheres(arel, wheres) wheres = Array(wheres) binaries = wheres.grep(Arel::Nodes::Binary) groups = binaries.group_by {|b| [b.class, b.left]} groups.each do |_, bins| arel.where(Arel::Nodes::And.new(bins)) end (wheres - binaries).each do |where| where = Arel.sql(where) if String === where arel.where(Arel::Nodes::Grouping.new(where)) end end |
#debug_sql ⇒ Object
Simulate the logic that occurs in #to_a
This will let us get a dump of the SQL that will be run against the DB for debug purposes without actually running the query.
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# File 'lib/squeel/adapters/active_record/relation.rb', line 309 def debug_sql if eager_loading? including = (@eager_load_values + @includes_values).uniq join_dependency = JoinDependency.new(@klass, including, []) construct_relation_for_association_find(join_dependency).to_sql else arel.to_sql end end |
#eager_load(*args) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 186 def eager_load(*args) if block_given? && args.empty? super(DSL.eval &Proc.new) else super end end |
#find_equality_predicates(nodes) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 290 def find_equality_predicates(nodes) nodes.map { |node| case node when Arel::Nodes::Equality node if node.left.relation.name == table_name when Arel::Nodes::Grouping find_equality_predicates([node.expr]) when Arel::Nodes::And find_equality_predicates(node.children) else nil end }.compact.flatten end |
#group(*args) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 208 def group(*args) if block_given? && args.empty? super(DSL.eval &Proc.new) else super end end |
#having(*args) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 248 def having(*args) if block_given? && args.empty? super(DSL.eval &Proc.new) else super end end |
#includes(*args) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 170 def includes(*args) if block_given? && args.empty? super(DSL.eval &Proc.new) else super end end |
#joins(*args) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 232 def joins(*args) if block_given? && args.empty? super(DSL.eval &Proc.new) else super end end |
#merge(r) ⇒ Object
We need to be able to support merging two relations that have a different base class. Stock ActiveRecord doesn’t have to do anything too special, because it’s already created predicates out of the where_values by now, and they’re already bound to the proper table.
Squeel, on the other hand, needs to do its best to ensure the predicates are still winding up against the proper table. The most “correct” way I can think of to do this is to try to emulate the default AR behavior – that is, de-squeelifying the *_values, erm… values by visiting them and converting them to ARel nodes before merging. Merging relations is a nifty little trick, but it’s another little corner of ActiveRecord where the magic quickly fades. :(
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# File 'lib/squeel/adapters/active_record/relation.rb', line 46 def merge(r) if relation_with_different_base?(r) r = r.clone.visit! end super(r) end |
#order(*args) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 216 def order(*args) if block_given? && args.empty? super(DSL.eval &Proc.new) else super end end |
#predicate_visitor ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 23 def predicate_visitor Visitors::PredicateVisitor.new( Context.new(join_dependency) ) end |
#preload(*args) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 178 def preload(*args) if block_given? && args.empty? super(DSL.eval &Proc.new) else super end end |
#prepare_relation_for_association_merge!(r, association_name) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 59 def prepare_relation_for_association_merge!(r, association_name) r.where_values.map! {|w| Squeel::Visitors::PredicateVisitor.can_visit?(w) ? {association_name => w} : w} r.having_values.map! {|h| Squeel::Visitors::PredicateVisitor.can_visit?(h) ? {association_name => h} : h} r.group_values.map! {|g| Squeel::Visitors::AttributeVisitor.can_visit?(g) ? {association_name => g} : g} r.order_values.map! {|o| Squeel::Visitors::AttributeVisitor.can_visit?(o) ? {association_name => o} : o} r.select_values.map! {|s| Squeel::Visitors::AttributeVisitor.can_visit?(s) ? {association_name => s} : s} r.joins_values.map! {|j| [Symbol, Hash, Nodes::Stub, Nodes::Join, Nodes::KeyPath].include?(j.class) ? {association_name => j} : j} r.includes_values.map! {|i| [Symbol, Hash, Nodes::Stub, Nodes::Join, Nodes::KeyPath].include?(i.class) ? {association_name => i} : i} end |
#relation_with_different_base?(r) ⇒ Boolean
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# File 'lib/squeel/adapters/active_record/relation.rb', line 54 def relation_with_different_base?(r) ::ActiveRecord::Relation === r && base_class.name != r.klass.base_class.name end |
#reorder(*args) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 224 def reorder(*args) if block_given? && args.empty? super(DSL.eval &Proc.new) else super end end |
#select(value = Proc.new) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 194 def select(value = Proc.new) if block_given? && Proc === value if value.arity > 0 to_a.select {|*block_args| value.call(*block_args)} else relation = clone relation.select_values += Array.wrap(DSL.eval &value) relation end else super end end |
#visit! ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 69 def visit! predicate_viz = predicate_visitor attribute_viz = attribute_visitor @where_values = predicate_viz.accept((@where_values - ['']).uniq) @having_values = predicate_viz.accept(@having_values.uniq.reject{|h| h.blank?}) @group_values = attribute_viz.accept(@group_values.uniq.reject{|g| g.blank?}) @order_values = attribute_viz.accept(@order_values.uniq.reject{|o| o.blank?}) @select_values = attribute_viz.accept(@select_values.uniq) self end |
#where(opts = Proc.new, *rest) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 240 def where(opts = Proc.new, *rest) if block_given? && Proc === opts super(DSL.eval &opts) else super end end |
#where_values_hash_with_squeel ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation.rb', line 351 def where_values_hash_with_squeel equalities = find_equality_predicates(predicate_visitor.accept(@where_values)) Hash[equalities.map { |where| [where.left.name, where.right] }] end |