Ruby on Rails - Cookie值仅在刷新时显示 [英] Ruby on Rails - Cookie value displays only on refresh

问题描述

我有一个下拉菜单，在我的一个视图中，允许我选择页面上的图像数量。我想记住在该页面上的选择，所以当用户回来时，显示的图像数量是他们上次选择的。

为了实现这一点，我如下所示，在控制器中设置cookie值：

 如果cookie [：per_page] .blank？ 
 cookies [：per_page] =50＃这是新用户的默认值，并且现有用户删除cookie 
 else 
 cookie [：per_page] = params [：noofimages_perpage ] .to_s＃这是在下拉菜单中选择的值
 end 
 @pp = cookies [：per_page] 
＃进一步处理cookie值
 end 
  

但我没有得到cookies [：per_page]中的值。

要检查Cookie中的值，我已将此行添加到我的视图中

 <％= @pp％> 
  

，并且视图只在刷新后显示值。

A视图的一部分在这里

 < select name =noofimages_perpageonchange =call the controller > 
< option value =50> 50< / option> 
< option value =100> 100< / option> 
< option value =150> 150< / option> 
< / select> 
  

阅读了几篇帖子和文章后，我明白，回传。

有关如何处理这个问题或有关工作的指示？

解决方案

>控制器中没有设置cookie，而是在控制器的响应中（因为它是浏览器的东西）。这意味着在页面呈现时设置cookie。您无法在此页面上访问它，但在下一页或刷新。

考虑重定向到同一页面

I have a drop down in one of my views, allowing me to select the number of images on the page. I want to remember the selection on that page, so when the user comes back, the number of images displayed are what they selected last time around.

To achieve this I am setting the cookie value from within the controller like this

if cookies[:per_page].blank?
    cookies[:per_page] = "50" # this is the default value for a new user and incase the existing user deletes the cookie
 else
    cookies[:per_page] = params[:noofimages_perpage].to_s # this is the value selected in the drop down   
 end
     @pp = cookies[:per_page] 
     # further processing with the cookie value here
end  

But I don't get the value in cookies[:per_page].

For checking the value in the cookie, I added this line to my view

<%= @pp %>  

and the view displays the value only after a refresh.

A Part of the view is here

<select name="noofimages_perpage" onchange="call the controller">
 <option value="50">50</option> 
 <option value="100">100</option>
 <option value="150">150</option>
</select>

After reading a few posts and articles, I understand that cookie write won't be available until the subsequent postback.

Some pointers on how to handle this or a work around please?

As far as possible I want to achieve this without touching the database.

Many Thanks

解决方案

A cookie isn't set in the controller but in the response of the controller (because it's a browser thing). that means the cookie is set when the page is rendered. you cant access it on this page but on the next page or refresh.

consider a redirect (to the same page) as a workaround

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