[英]Ruby on Rails - How to add an n:m association in a generic method
假设两个模型具有has_and_belong_to_many关系,例如,驾驶员和汽车在Rails中,您可以通过使用添加新关系
driver.cars << car
现在,如何使这条线通用? 在控制器中,该方法调用移交驾驶员实例,指示关联类“汽车”的字符串和要添加的汽车ID数组。
add_association(@driver, 'car', [car_ids])
方法看起来像这样。
def add_association(object, association_class_name, ids)
model = association_class_name.constantize
associations = association_class_name.pluralize
ids.each do |incoming_id|
association = model.find_by_id(incoming_id)
if association.nil?
return false
else
object.associations << association # throws NoMethodError: undefined method `associations' for #<Driver:0x...
end
end
end
有什么建议么?
用户public_send方法是这样的:
def add_association(object, association_class_name, ids)
model = association_class_name.constantize
associations = association_class_name.underscore.pluralize
ids.each do |incoming_id|
association = model.find_by_id(incoming_id)
if association.nil?
return false
else
object.public_send associations << association
end
end
end
参考: public_send
让我知道它是否无效。
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