如何在组和用户之间创建联接操作？

Question

user.rb

  has_many :memberships, :dependent => :destroy
  has_many :groups, :through => :memberships

membership.rb

class Membership < ActiveRecord::Base
  attr_accessible :user_id, :group_id
  belongs_to :user
  belongs_to :group
  validates_uniqueness_of :user_id, :message => "You can only join one group!"

end

group.rb

has_many :memberships, :dependent => :destroy
has_many :users, :through => :memberships

groups_controller.rb

def join
    @group = Group.find(params[:id])
    @m = @group.memberships.build(:user_id => current_user.id)
    respond_to do |format|
      if @m.save
        format.html { redirect_to(@group, :notice => 'You have joined this group.') }
        format.xml  { head :ok }
      else
        format.html { redirect_to(@group, :notice => 'Join error.') }
        format.xml  { render :xml => @group.errors, :status => :unprocessable_entity }
      end
    end
  end

memberships_controller.rb

class MembershipsController < ApplicationController
before_filter :authenticate_user!
  def create
    @membership = current_user.memberships.build(:group_id => params[:group_id])
    if @membership.save
      flash[:notice] = "You have joined this group."
      redirect_to :back
    else
      flash[:error] = "Unable to join."
      redirect_to :back
    end
  end

  def destroy
    @membership = current_user.memberships.find(params[:id])
    @membership.destroy
    flash[:notice] = "Removed membership."
        redirect_to :back
  end
end

用户通过成员资格模型获得组，这是一个连接表。我的问题。如何创建联接操作以供用户单击以便他们可以加入组？

Answer 1

您已完成步骤1，即添加控制器操作。现在，您只需添加适当的路线并在视图中将其连接起来。

在routes.rb：

中

resources :groups do
    get 'join', :on => :member
end

在您的视图文件中：

<%= link_to "Join this group", join_group_path(@group) %>

就是这样！