Question

我有一个看起来非常像这样的索引方法：

  def index
    if params[:brand]
      @users = User.includes(:brand).where(brand_id: params[:brand]).order("#{sort_column} #{sort_direction}").page(params[:page]).per(10)
    elsif params[:search]
      @user = User.includes(:brand).find_by_client_code(params[:search])
      redirect_to edit_user_path(@user)
    elsif params[:page] == 'all'
      @users = User.includes(:brand).order("#{sort_column} #{sort_direction}").all
    elsif params[:state]
      @users = User.includes(:brand).where(state: params[:state]).page(params[:page]).per(10)
    else
      @users = User.includes(:brand).order("#{sort_column} #{sort_direction}").page(params[:page]).per(10)
    end
  end

我知道，这很混乱但是很有效。现在我正在尝试重构它，我无法弄清楚将它拆分成较小的集合的最佳方法，而不会使我的路线复杂化。

  def index
    [:brand, :page, :search, :state].each do |param|
      if params[:page] == 'all'
        @users = User.includes(:brand).order(column + ' ' + direction)
      elsif params.key?(param)
        param
      else
        @users = User.includes(:brand).order(column + ' ' + direction)
                     .page(params[:page]).per(10)
      end
    end
  end

  def brand
    @users = User.includes(:brand).where('brand_id in (?)', params[:brand])
                 .order(column + ' ' + direction).page(params[:page]).per(10)
  end

  def state
    @users = User.includes(:brand).where(state: params[:state])
                 .page(params[:page]).per(10)
  end

  def search
    @user = User.includes(:brand).find_by_client_code(params[:search])
    redirect_to edit_user_path(@user)
  end

以上不起作用，但你明白了。有谁知道处理这种情况的好方法？欢呼声。

Answer 1

我可能会这样做 -

首先，更新此代码，您已将sort_column和sort_direction方法定义为默认值：

def sort_column
  colum_name = params[:colum_name]
  colum_name ||= 'id'
end

def  sort_direction
  direction = params[:direction]
  direction ||= 'ASC'
end

添加一个新方法，让per_page（在您拥有sort_column和sort_direction的同一位置）来自params或默认来自User class：

def per_page
  per = params[:per_page]
  per ||= User.per_page
end

app / models / user.rb 中的

：

scope :with_brand_id, ->(id) { where(brand_id: id) }
scope :with_state,    ->(state) { where(state: state) }
scope :order_with,    ->(column_name, direction) { order("#{sort_column} #{sort_direction}") }

# never use/avoid magic numbers in your application at multiple places as they gets unmanageable as your application grows
# single place to manage your per page entries for users.
def self.per_page
  10
end

# easy to use key:value based arguments since you're using Ruby 2, cheers!
def self.fetch_with_brand(brand: nil, state: nil, page: nil, sort_column: 'id', sort_direction: 'ASC', per_page: User.per_page)
  user_scope, pagination_scope_applies =  if brand.present?
    [self.with_brand_id(brand), true]
  elsif state.present?
    [self.with_state(state), true]
  else
    [self.scoped, (page != 'all')]
  end

  user_scope.merge(pagination_scope(page, per_page)) if pagination_scope_applies
  user_scope.includes(:brand).order_with(sort_column, sort_direction)
end

# since I am not sure about your implementation of `page` and `per` methods, I'd create a class method, otherwise you can create a `scope` for this, too
def self.pagination_scope(page_number, per_page)
  self.page(page_number).per(per_page)
end

您是否在上述代码中找到了行[self.scoped, (page != 'all')]？此处self.scoped等于self.all（评估时），但我们必须使用scoped代替all，因为在Rails 3中它提供了数组，而在Rails 4中它将是一个 ActiveRecord :: Relation 对象，因此如果你在Rails 4上，你可以使用self.all。注意：scoped是在Rails 4中弃用，而不是all。

另外，我想在这里指出一个问题。在您的代码中，您优先考虑params[:page] == 'all'条件，然后优先考虑params[:search]。在我上面提到的代码中，优先考虑search然后优先考虑page，但是你明白了，对吗？

现在，让我们在控制器中添加用户特定的params方法：

def user_params
  params.slice(:brand, :page, :state).merge!({sort_column: sort_column, sort_direction: sort_direction, per_page: per_page })
end

但是，在Rails 4中，使用强参数更容易，例如：params.require(:user).permit(:search,..)等。

现在，您的控制器的索引方法可能如下所示：

def index
  if params[:search].present?
    @user = User.find_by_client_code(params[:search])
    redirect_to edit_user_path(@user)
  else
    @users = User.fetch_with_brand(user_params)
  end
end

如果您倾向于将用户重定向到更多地方的编辑页面，您可以进一步重构：

before_filter :redirect_to_edit, only: [:index, :some_other_method_name]

def index
  @users = User.fetch_with_brand(user_params)
end

def redirect_to_edit
  if params[:search].present?
    @user = User.find_by_client_code(params[:search])
    redirect_to edit_user_path(@user)
  end
end

您现在已经拥有了瘦控制器。

Rails：基于params的集合

1 个答案: