Ruby on rails 重构可选参数方法以删除'if'语句
我有一个方法Ruby on rails 重构可选参数方法以删除'if'语句,ruby-on-rails,ruby,optional-parameters,Ruby On Rails,Ruby,Optional Parameters,我有一个方法select\u active\u buildings,其中三个参数默认为nil,可以使用提供的信息过滤我的数据库 def select_active_buildings(category:nil, upgrader:nil, upgrade_resource:nil) my_active_buildings = self.buildings.active(self.townhall_level) if category && upgrader &&a
select\u active\u buildings
,其中三个参数默认为nil
,可以使用提供的信息过滤我的数据库
def select_active_buildings(category:nil, upgrader:nil, upgrade_resource:nil)
my_active_buildings = self.buildings.active(self.townhall_level)
if category && upgrader && upgrade_resource
return my_active_buildings.where(category:category, upgrader:upgrader, upgrade_resource:upgrade_resource)
elsif category && upgrader
return my_active_buildings.where(category:category, upgrader:upgrader)
elsif category && upgrade_resource
return my_active_buildings.where(category:category, upgrade_resource:upgrade_resource)
elsif upgrader && upgrade_resource
return my_active_buildings.where(upgrader:upgrader, upgrade_resource:upgrade_resource)
elsif category
return my_active_buildings.where(category:category)
elsif upgrader
return my_active_buildings.where(upgrader:upgrader)
elsif upgrade_resource
return my_active_buildings.where(upgrade_resource:upgrade_resource)
else
return my_active_buildings
end
end
我需要帮助重构此方法。我会这样做:
def select_active_buildings(category: nil, upgrader: nil, upgrade_resource: nil)
my_active_buildings = self.buildings.active(self.townhall_level)
cond = {
category: category,
upgrader: upgrader,
upgrade_resource: upgrade_resource
}.select { |k, v| v }
my_active_buildings.where(cond)
end
或者
或者,如果我真的不关心select\u active\u函数
级别的语法检查
def select_active_buildings(cond)
my_active_buildings = self.buildings.active(self.townhall_level)
my_active_buildings.where(cond)
end
如果您确实不想要.where({})
案例,您可以将返回我的活动建筑(如果条件为空)
。我会这样做:
def select_active_buildings(category: nil, upgrader: nil, upgrade_resource: nil)
my_active_buildings = self.buildings.active(self.townhall_level)
cond = {
category: category,
upgrader: upgrader,
upgrade_resource: upgrade_resource
}.select { |k, v| v }
my_active_buildings.where(cond)
end
或者
或者,如果我真的不关心select\u active\u函数
级别的语法检查
def select_active_buildings(cond)
my_active_buildings = self.buildings.active(self.townhall_level)
my_active_buildings.where(cond)
end
如果您确实不想使用
.where({})
案例,可以将返回my_active_buildings If cond.empty?
放在它前面。假设您正在使用ActiveRecord、Mongoid或其他可链接的where
案例,您可以利用以下事实:
o.where(:a => b, :c => d)
同:
o.where(:a => b).where(:c => d)
这让您可以这样做:
def select_active_buildings(category: nil, upgrader: nil, upgrade_resource: nil)
buildings = self.buildings.active(self.townhall_level)
buildings = buildings.where(category: category) if(category)
buildings = buildings.where(upgrader: upgrader) if(upgrader)
buildings = buildings.where(upgrade_resource: upgrade_resource) if(upgrade_resource)
buildings
end
甚至:
def select_active_buildings(conditions)
buildings = self.buildings.active(self.townhall_level)
%i[category upgrader upgrade_resource]
.select { |f| conditions.has_key?(f) }
.inject(buildings) { |q, f| q.where(f => conditions[f]) }
end
假设您正在使用ActiveRecord、Mongoid或其他可链接的
where
,您可以利用以下事实:
o.where(:a => b, :c => d)
同:
o.where(:a => b).where(:c => d)
这让您可以这样做:
def select_active_buildings(category: nil, upgrader: nil, upgrade_resource: nil)
buildings = self.buildings.active(self.townhall_level)
buildings = buildings.where(category: category) if(category)
buildings = buildings.where(upgrader: upgrader) if(upgrader)
buildings = buildings.where(upgrade_resource: upgrade_resource) if(upgrade_resource)
buildings
end
甚至:
def select_active_buildings(conditions)
buildings = self.buildings.active(self.townhall_level)
%i[category upgrader upgrade_resource]
.select { |f| conditions.has_key?(f) }
.inject(buildings) { |q, f| q.where(f => conditions[f]) }
end
如果(a)您的代码按预期工作,(b)您的代码是真实代码,而不是示例代码,以及(c)您的代码包含在问题主体中,则此问题更适合此问题。如果您希望通过同行评议来改进代码的各个方面,请将其发布在代码评议上。谢谢,你们都是对的。如前所述-这应该在代码评议上:)是的,我下次会在那里发布,哇!现在有可能改变吗?或者干脆不提这个问题?这个问题会更好,只要(a)您的代码按预期工作,(b)您的代码是真实代码,而不是示例代码,以及(c)您的代码包含在问题主体中,这个问题就可以适用。如果您希望通过同行评议来改进代码的各个方面,请将其发布在代码评议上。谢谢,你们都是对的。如前所述-这应该在代码评议上:)是的,我下次会在那里发布,哇!现在有可能改变吗?或者干脆别管它?最后一个变量是
where(cond.slice(:category,…)
。最后一个变量是where(cond.slice(:category,…)
。我选择了第一个选项。非常感谢。我同意你的第一个选择。非常感谢。