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author | Jon Leighton <j@jonathanleighton.com> | 2011-03-10 23:55:29 +0000 |
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committer | Jon Leighton <j@jonathanleighton.com> | 2011-03-10 23:55:29 +0000 |
commit | aef3629c6ebae013333e11911934dfff28de875a (patch) | |
tree | fb3759d2078ef2c34ba2c33c566b45960a58482b /activerecord/lib/active_record/associations/join_dependency/join_association.rb | |
parent | 582edaa1ffd6d875e18c50e36e144544209fd158 (diff) | |
download | rails-aef3629c6ebae013333e11911934dfff28de875a.tar.gz rails-aef3629c6ebae013333e11911934dfff28de875a.tar.bz2 rails-aef3629c6ebae013333e11911934dfff28de875a.zip |
Refactor JoinAssociation
Diffstat (limited to 'activerecord/lib/active_record/associations/join_dependency/join_association.rb')
-rw-r--r-- | activerecord/lib/active_record/associations/join_dependency/join_association.rb | 154 |
1 files changed, 54 insertions, 100 deletions
diff --git a/activerecord/lib/active_record/associations/join_dependency/join_association.rb b/activerecord/lib/active_record/associations/join_dependency/join_association.rb index f26881a6c6..750f03a120 100644 --- a/activerecord/lib/active_record/associations/join_dependency/join_association.rb +++ b/activerecord/lib/active_record/associations/join_dependency/join_association.rb @@ -57,88 +57,46 @@ module ActiveRecord end def join_to(relation) + tables = @tables.dup foreign_table = parent_table - index = 0 # The chain starts with the target table, but we want to end with it here (makes # more sense in this context), so we reverse - chain.reverse.each do |reflection| - table = tables[index] - conditions = [] - - if reflection.source_reflection.nil? - case reflection.macro - when :belongs_to - key = reflection.association_primary_key - foreign_key = reflection.foreign_key - when :has_many, :has_one - key = reflection.foreign_key - foreign_key = reflection.active_record_primary_key - when :has_and_belongs_to_many - # For habtm, we need to deal with the join table at the same time as the - # target table (because unlike a :through association, there is no reflection - # to represent the join table) - table, join_table = table - - join_key = reflection.foreign_key - join_foreign_key = reflection.active_record.primary_key - - relation = relation.join(join_table, join_type).on( - join_table[join_key]. - eq(foreign_table[join_foreign_key]) - ) - - # We've done the first join now, so update the foreign_table for the second - foreign_table = join_table - - key = reflection.klass.primary_key - foreign_key = reflection.association_foreign_key - end + chain.reverse.each_with_index do |reflection, i| + table = tables.shift + + case reflection.source_macro + when :belongs_to + key = reflection.association_primary_key + foreign_key = reflection.foreign_key + when :has_and_belongs_to_many + # Join the join table first... + relation = relation.from(join( + table, + table[reflection.foreign_key]. + eq(foreign_table[reflection.active_record_primary_key]) + )) + + foreign_table, table = table, tables.shift + + key = reflection.association_primary_key + foreign_key = reflection.association_foreign_key else - case reflection.source_reflection.macro - when :belongs_to - key = reflection.association_primary_key - foreign_key = reflection.foreign_key - when :has_many, :has_one - key = reflection.foreign_key - foreign_key = reflection.source_reflection.active_record_primary_key - when :has_and_belongs_to_many - table, join_table = table - - join_key = reflection.foreign_key - join_foreign_key = reflection.klass.primary_key - - relation = relation.join(join_table, join_type).on( - join_table[join_key]. - eq(foreign_table[join_foreign_key]) - ) - - foreign_table = join_table - - key = reflection.klass.primary_key - foreign_key = reflection.association_foreign_key - end + key = reflection.foreign_key + foreign_key = reflection.active_record_primary_key end + conditions = self.conditions[i].dup conditions << table[key].eq(foreign_table[foreign_key]) - conditions << reflection_conditions(index, table) if reflection.klass.finder_needs_type_condition? conditions << reflection.klass.send(:type_condition, table) end - ands = relation.create_and(conditions.flatten.compact) - - join = relation.create_join( - table, - relation.create_on(ands), - join_type) - - relation = relation.from(join) + relation = relation.from(join(table, *conditions)) # The current table in this iteration becomes the foreign table in the next foreign_table = table - index += 1 end relation @@ -150,18 +108,18 @@ module ActiveRecord end def table - if tables.last.is_a?(Array) - tables.last.first - else - tables.last - end + tables.last end def aliased_table_name table.table_alias || table.name end - protected + def conditions + @conditions ||= reflection.conditions.reverse + end + + private def table_alias_for(reflection, join = false) name = alias_tracker.pluralize(reflection.name) @@ -170,55 +128,51 @@ module ActiveRecord name end - private - # Generate aliases and Arel::Table instances for each of the tables which we will # later generate joins for. We must do this in advance in order to correctly allocate # the proper alias. def setup_tables - @tables = chain.map do |reflection| - table = alias_tracker.aliased_table_for( + @tables = [] + chain.each do |reflection| + @tables << alias_tracker.aliased_table_for( reflection.table_name, table_alias_for(reflection, reflection != self.reflection) ) - # For habtm, we have two Arel::Table instances related to a single reflection, so - # we just store them as a pair in the array. - if reflection.macro == :has_and_belongs_to_many || - (reflection.source_reflection && reflection.source_reflection.macro == :has_and_belongs_to_many) - - join_table = alias_tracker.aliased_table_for( + if reflection.source_macro == :has_and_belongs_to_many + @tables << alias_tracker.aliased_table_for( (reflection.source_reflection || reflection).options[:join_table], table_alias_for(reflection, true) ) - - [table, join_table] - else - table end end - # The joins are generated from the chain in reverse order, so - # reverse the tables too (but it's important to generate the aliases in the 'forward' - # order, which is why we only do the reversal now. + # We construct the tables in the forward order so that the aliases are generated + # correctly, but then reverse the array because that is the order in which we will + # iterate the chain. @tables.reverse! end - def process_conditions(conditions, table_name) - if conditions.respond_to?(:to_proc) - conditions = instance_eval(&conditions) - end - - Arel.sql(sanitize_sql(conditions, table_name)) + def join(table, *conditions) + conditions = sanitize_conditions(table, conditions) + table.create_join(table, table.create_on(conditions), join_type) end - def sanitize_sql(condition, table_name) - active_record.send(:sanitize_sql, condition, table_name) + def sanitize_conditions(table, conditions) + conditions = conditions.map do |condition| + condition = active_record.send(:sanitize_sql, interpolate(condition), table.table_alias || table.name) + condition = Arel.sql(condition) unless condition.is_a?(Arel::Node) + condition + end + + conditions.length == 1 ? conditions.first : Arel::Nodes::And.new(conditions) end - def reflection_conditions(index, table) - reflection.conditions.reverse[index].map do |condition| - process_conditions(condition, table.table_alias || table.name) + def interpolate(conditions) + if conditions.respond_to?(:to_proc) + instance_eval(&conditions) + else + conditions end end |