Module: Squeel::Adapters::ActiveRecord::RelationExtensions
- Defined in:
- lib/squeel/adapters/active_record/relation_extensions.rb,
lib/squeel/adapters/active_record/3.0/relation_extensions.rb,
lib/squeel/adapters/active_record/3.1/relation_extensions.rb,
lib/squeel/adapters/active_record/3.2/relation_extensions.rb,
lib/squeel/adapters/active_record/4.0/relation_extensions.rb
Defined Under Namespace
Modules: WhereChainCompatibility
Instance Attribute Summary collapse
Class Method Summary
collapse
Instance Method Summary
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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_extensions.rb', line 16
def join_dependency
@join_dependency ||= (
build_join_dependency(
Arel::SelectManager.new(table.engine, table),
joins_values
) && @join_dependency
)
end
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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, itself.
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.
If you’d like to read more about alias_method_chain, see erniemiller.org/2011/02/03/when-to-use-alias_method_chain/
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 387
def self.included(base)
base.class_eval do
alias_method_chain :where_values_hash, :squeel
end
end
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Instance Method Details
#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_extensions.rb', line 70
def attrs_to_orderings(order)
order.map do |o|
Arel::Attribute === o ? o.asc : o
end
end
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#build_arel ⇒ Object
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# File 'lib/squeel/adapters/active_record/3.0/relation_extensions.rb', line 23
def build_arel
arel = table
arel = build_join_dependency(arel, @joins_values) unless @joins_values.empty?
arel = collapse_wheres(arel, where_visit((@where_values - ['']).uniq))
arel = arel.having(*having_visit(@having_values.uniq.reject{|h| h.blank?})) unless @having_values.empty?
arel = arel.take(connection.sanitize_limit(@limit_value)) if @limit_value
arel = arel.skip(@offset_value) if @offset_value
arel = arel.group(*group_visit(@group_values.uniq.reject{|g| g.blank?})) unless @group_values.empty?
arel = arel.order(*order_visit(@order_values.uniq.reject{|o| o.blank?})) unless @order_values.empty?
arel = build_select(arel, select_visit(@select_values.uniq))
arel = arel.from(from_visit(@from_value)) if @from_value
arel = arel.lock(@lock_value) if @lock_value
arel
end
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#build_from ⇒ Object
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# File 'lib/squeel/adapters/active_record/4.0/relation_extensions.rb', line 58
def build_from
opts, name = from_visit(from_value)
case opts
when ::ActiveRecord::Relation
name ||= 'subquery'
opts.arel.as(name.to_s)
when ::Arel::SelectManager
name ||= 'subquery'
opts.as(name.to_s)
else
opts
end
end
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#build_join_dependency(relation, joins) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 107
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] || []).uniq
string_joins = (buckets[:string_join] || []).map { |x|
x.strip
}.uniq
join_list = join_nodes + custom_join_ast(manager, string_joins)
self.join_dependency = JoinDependency.new(
@klass,
association_joins,
join_list
)
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_list
manager
end
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#build_joins ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 152
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] || []).uniq
string_joins = (buckets[:string_join] || []).map { |x|
x.strip
}.uniq
join_list = join_nodes + custom_join_ast(manager, string_joins)
self.join_dependency = JoinDependency.new(
@klass,
association_joins,
join_list
)
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_list
manager
end
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#build_order(arel) ⇒ Object
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# File 'lib/squeel/adapters/active_record/4.0/relation_extensions.rb', line 72
def build_order(arel)
orders = order_visit(dehashified_order_values)
orders = reverse_sql_order(attrs_to_orderings(orders)) if reverse_order_value
orders = orders.uniq.reject(&:blank?).flat_map do |order|
case order
when Symbol
table[order].asc
when Hash
order.map { |field, dir| table[field].send(dir) }
else
order
end
end
arel.order(*orders) unless orders.empty?
end
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#build_where(opts, other = []) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 248
def build_where(opts, other = [])
case opts
when String, Array
super
else [opts, *other].map do |arg|
case arg
when Array @klass.send(:sanitize_sql, arg)
when Hash
@klass.send(:expand_hash_conditions_for_aggregates, arg)
else
arg
end
end
end
end
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#collapse_wheres(arel, wheres) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 266
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
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#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_extensions.rb', line 346
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
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#dehashified_order_values ⇒ Object
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# File 'lib/squeel/adapters/active_record/4.0/relation_extensions.rb', line 114
def dehashified_order_values
order_values.map { |o|
if Hash === o && o.values.all? { |v| [:asc, :desc].include?(v) }
o.map { |field, dir| table[field].send(dir) }
else
o
end
}
end
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#eager_load(*args) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 170
def eager_load(*args)
if block_given? && args.empty?
super(DSL.eval &Proc.new)
else
super
end
end
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#find_equality_predicates(nodes) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 282
def find_equality_predicates(nodes)
nodes.map { |node|
case node
when Arel::Nodes::Equality
if node.left.respond_to?(:relation) &&
node.left.relation.name == table_name
node
end
when Arel::Nodes::Grouping
find_equality_predicates([node.expr])
when Arel::Nodes::And
find_equality_predicates(node.children)
else
nil
end
}.compact.flatten
end
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#flatten_nodes(nodes) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 300
def flatten_nodes(nodes)
nodes.map { |node|
case node
when Array
flatten_nodes(node)
when Nodes::And
flatten_nodes(node.children)
when Nodes::Grouping
flatten_nodes(node.expr)
else
node
end
}.flatten
end
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#from(*args) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 240
def from(*args)
if block_given? && args.empty?
super(DSL.eval &Proc.new)
else
super
end
end
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#group(*args) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 192
def group(*args)
if block_given? && args.empty?
super(DSL.eval &Proc.new)
else
super
end
end
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#having(*args) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 232
def having(*args)
if block_given? && args.empty?
super(DSL.eval &Proc.new)
else
super
end
end
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#includes(*args) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 154
def includes(*args)
if block_given? && args.empty?
super(DSL.eval &Proc.new)
else
super
end
end
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#joins(*args) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 216
def joins(*args)
if block_given? && args.empty?
super(DSL.eval &Proc.new)
else
super
end
end
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#merge(r, equalities_resolved = false) ⇒ Object
We need to be able to support merging two relations without having to get our hooks too deeply into Active Record. That proves to be easier said than done. I hate Relation#merge. If Squeel has a nemesis, Relation#merge would be it.
Whatever code you see here currently is my current best attempt at coexisting peacefully with said nemesis.
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 40
def merge(r, equalities_resolved = false)
if ::ActiveRecord::Relation === r && !equalities_resolved
if self.table_name != r.table_name
super(r.visited)
else
merge_resolving_duplicate_squeel_equalities(r)
end
else
puts r.inspect if r.is_a?(Proc)
super(r)
end
end
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#merge_resolving_duplicate_squeel_equalities(r) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 315
def merge_resolving_duplicate_squeel_equalities(r)
left = clone
right = r.clone
left.where_values = flatten_nodes(left.where_values)
right.where_values = flatten_nodes(right.where_values)
right_equalities = right.where_values.select do |obj|
Nodes::Predicate === obj && obj.method_name == :eq
end
right.where_values -= right_equalities
left.where_values = resolve_duplicate_squeel_equalities(
left.where_values + right_equalities
)
left.merge(right, true)
end
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#order(*args) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 200
def order(*args)
if block_given? && args.empty?
super(DSL.eval &Proc.new)
else
super
end
end
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#order!(*args) ⇒ Object
This is copied directly from 4.0.0’s implementation, but adds an extra exclusion for Squeel::Nodes::Node to fix #248. Can be removed if/when rails/rails#11439 is merged.
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# File 'lib/squeel/adapters/active_record/4.0/relation_extensions.rb', line 93
def order!(*args)
args.flatten!
validate_order_args args
references = args.reject { |arg|
Arel::Node === arg || Squeel::Nodes::Node === arg
}
references.map! { |arg| arg =~ /^([a-zA-Z]\w*)\.(\w+)/ && $1 }.compact!
references!(references) if references.any?
args = args.map { |arg|
arg.is_a?(Symbol) ? "#{quoted_table_name}.#{arg} ASC" : arg
}
self.order_values = args + self.order_values
self
end
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#preload(*args) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 162
def preload(*args)
if block_given? && args.empty?
super(DSL.eval &Proc.new)
else
super
end
end
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#reorder(*args) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 208
def reorder(*args)
if block_given? && args.empty?
super(DSL.eval &Proc.new)
else
super
end
end
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#resolve_duplicate_squeel_equalities(wheres) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 330
def resolve_duplicate_squeel_equalities(wheres)
seen = {}
wheres.reverse.reject { |n|
nuke = false
if Nodes::Predicate === n && n.method_name == :eq
nuke = seen[n.expr]
seen[n.expr] = true
end
nuke
}.reverse
end
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#select(value = Proc.new) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 178
def select(value = Proc.new)
if block_given? && Proc === value
if value.arity > 0 || (Squeel.sane_arity? && 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
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#select_for_count ⇒ Object
So, building a select for a count query in Active Record is pretty heavily dependent on select_values containing strings. I’d initially expected that I could just hack together a fix to select_for_count and everything would fall in line, but unfortunately, pretty much everything from that point on in ActiveRecord::Calculations#perform_calculation expects the column to be a string, or at worst, a symbol.
In the long term, I would like to refactor the code in Rails core, but for now, I’m going to settle for this hack that tries really hard to coerce things to a string.
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 87
def select_for_count
visited_values = select_visit(select_values.uniq)
if visited_values.size == 1
select = visited_values.first
str_select = case select
when String
select
when Symbol
select.to_s
else
select.to_sql if select.respond_to?(:to_sql)
end
str_select if str_select && str_select !~ /[,*]/
else
:all
end
end
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#visit! ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 57
def visit!
self.where_values = where_visit((where_values - ['']).uniq)
self.having_values = having_visit(having_values.uniq.reject{|h| h.blank?})
self.order_values = order_visit(order_values.uniq.reject{|o| o.blank?})
self.select_values = select_visit(select_values.uniq)
self
end
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#visited ⇒ Object
We don’t need to call with_default_scope in AR 3.0.x. In fact, since there is no with_default_scope in 3.0.x, that’d be pretty dumb.
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# File 'lib/squeel/adapters/active_record/3.0/relation_extensions.rb', line 19
def visited
with_default_scope.visit!
end
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#where(opts = :chain, *rest) ⇒ Object
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 224
def where(opts = Proc.new, *rest)
if block_given? && Proc === opts
super(DSL.eval &opts)
else
super
end
end
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#where_values_hash_with_squeel ⇒ Object
where_values_hash is used in scope_for_create. It’s what allows new records to be created with any equality values that exist in your model’s default scope. We hijack it in order to dig down into And and Grouping nodes, which are equivalent to seeing top-level Equality nodes in stock AR terms.
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# File 'lib/squeel/adapters/active_record/relation_extensions.rb', line 398
def where_values_hash_with_squeel
equalities = find_equality_predicates(where_visit(with_default_scope.where_values))
binds = Hash[bind_values.find_all(&:first).map { |column, v| [column.name, v] }]
Hash[equalities.map { |where|
name = where.left.name
[name, binds.fetch(name.to_s) { where.right }]
}]
end
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