Class: SmartCollection::ScopeBuilder

Inherits:
Object
  • Object
show all
Defined in:
lib/smart_collection/scope_builder.rb

Instance Method Summary collapse

Constructor Details

#initialize(rule, klass) ⇒ ScopeBuilder

Returns a new instance of ScopeBuilder.



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# File 'lib/smart_collection/scope_builder.rb', line 3

def initialize rule, klass
  @rule = rule
  @klass = klass
  @klass_hash = {}
end

Instance Method Details

#build ⇒ Object 



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# File 'lib/smart_collection/scope_builder.rb', line 9

def build
  rule_to_bulk_queries @rule
  bulk_load
  rule_to_scope @rule
end

#bulk_load ⇒ Object 



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# File 'lib/smart_collection/scope_builder.rb', line 15

def bulk_load
  @klass_hash = @klass_hash.map do |klass_name, ids|
    [klass_name, Object.const_get(klass_name).where(id: ids).map{|x| [x.id, x]}.to_h]
  end.to_h
end

#rule_to_bulk_queries(rule) ⇒ Object 



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# File 'lib/smart_collection/scope_builder.rb', line 21

def rule_to_bulk_queries rule
  case
  when arr = (rule['or'] || rule['and'])
    arr.each{|x| rule_to_bulk_queries x}
  when assoc = rule['association']
    ids = @klass_hash[assoc['class_name']] ||= []
    ids << assoc['id']
  end
end

#rule_to_scope(rule) ⇒ Object 



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# File 'lib/smart_collection/scope_builder.rb', line 31

def rule_to_scope rule
  case
  when ors = rule['or']
    ors.map{|x| rule_to_scope x}.inject(:or)
  when ands = rule['and']
    ands.map{|x| rule_to_scope x}.inject(:merge)
  when assoc = rule['association']
    @klass_hash[assoc['class_name']][assoc['id']].association(assoc['source']).scope
  when cond = rule['condition']
    scope = @klass
    scope = scope.joins(cond['joins'].to_sym) if cond['joins']
    scope.where(cond['where'])
  end
end