如何创建一个简单的活动流？

Question

我想实现一个简单的活动流。

Given that User abc creates a post 123 
And User xyz comments on 123. 
Then user abc's activity stream should look something like: 
<ul> 
    <li>User <a href="https://*.com/users/abc">abc</a> created a post <a href="https://*.com/users/abc/posts/123">123</a></li> 
    <li>User <a href="https://*.com/users/xyz">xyz</a> commented on post <a href="https://*.com/users/abc/posts/123">123</a></li> 
</ul> 

我更喜欢填充活动模型（而不是控制器中的多个查询）。我添加了一个“after_create”钩到文章和评论模型既填充活动：

class Post < ActiveRecord 
    after_create do 
    ActivityCreate(:user_id => self.user_id, :description => "created a post") 
    end 
end 

我想保存我需要创建路线和链接，如POST_ID等特殊领域的，但我可能会有更多的活动，我想以后跟踪，喜欢，不喜欢，最喜欢等，我想要一个灵活的方式来创建活动描述。

所以我的问题是，什么是将link_to放入活动描述的有效方法？是否有任何C风格的printf方式列表助手以后评估？

排序的是这样的：

描述= [ “？用户评论交？”，user_path（User.find（self.user_id）），post_path（Post.find（self.id））]

然后在模板方面评估这个？

Answer 1

这是我第一次关于你的情况。也许它启发你足够:)

class Activity < ActiveRecord::Base 
    #this might be a comment or a post or something else 
    belongs_to :changed_item, :polymorphic => true 
    #who did it? 
    belongs_to :user 
    #what did he do? 
    validates_presence_of :changes 

    def msg 
    #do fancy text generation 
    if changes.new_record 
     "#{user.name} created a #{changed_item.class}" 
    else 
     "#{user.name} changed #{changes.length} attributes of the #{changed_item.class} #{changed_item.title}" 
    end 
    end 

    def initialize(model, user) 
    #fetch changes and remember user and changed model 
    self.changed_item = model 
    self.user = user 
    self.changes << model.changed_attributes.merge({:new_record => model.new_record?}) 
    end 
end 

class Post < ActiveRecord::Base 
    after_save do 
    #remember who to be blamed 
    Activity.create(self, current_user) 
    end 
end 

class User < ActiveRecord::Base 
    #the users activities 
    has_many :activities 
end