Question

Rails在destroy方法中找不到Model ID但在新方法中有效。不确定我是否遗漏了一些明显的东西。

我试图通过“取消订阅链接”销毁订阅的实例。（订阅是用户和主题之间的联合表）。该视图位于主题展示页面上。

我感到困惑的是，我能够在新方法中使用@theme = Theme.find（params [：theme_id]）创建订阅实例，但错误会在destroy方法中出现。请参阅以下错误：

SubscriptionsController＃destroy中的 ActiveRecord :: RecordNotFound 无法找到没有ID的主题

提取的来源（第19行）：

def destroy
    @theme = Theme.find(params[:theme_id]) #line 19
    @current_sub = Subscription.where(:user_id => current_user.id, :theme_id => @theme.id)
    @current_sub.destroy
    flash[:notice] = "You have unsubscribed to #{@theme.name}"

订阅控制器：

class SubscriptionsController < ApplicationController
def new
    @theme = Theme.find(params[:theme_id])
    @current_sub = Subscription.where(:user_id => current_user.id, :theme_id => @theme.id)
    while @current_sub.count == 0 do
        @subscription = Subscription.new
        @subscription.user_id = current_user.id
        @subscription.theme_id = @theme.id
            if @subscription.save
                flash[:notice] = "You have subscribed to #{@theme.name}"
                redirect_to root_path
            else
                render new
            end 
    end
end

def destroy
    @theme = Theme.find(params[:theme_id])
    @current_sub = Subscription.where(:user_id => current_user.id, :theme_id => @theme.id)
    @current_sub.destroy
    flash[:notice] = "You have unsubscribed to #{@theme.name}"
    redirect_to root_path
end
end

主题显示视图：

<h1>QUOTES, YO.</h1>
<br>
<h3>
<% if @current_sub.count == 0 %>
<%= link_to "Subscribe!", new_subscription_path(:user_id => current_user.id, :theme_id => @theme.id, data: { confirm: 'Are you sure you want to subscribe?' } )%>
<% else %>
<%= button_to "UnSubscribe!", subscription_path(@current_sub), :method => :delete, data: { confirm: 'Are you sure you want to unsubscribe?' } %>
<% end %>
</h3>
<br>
<% @theme.inspirations.each do |i| %>
    <%= i.quote %>
    <br>
<% end %>
<br>
<%= link_to "Back to Main", root_path %>

主题控制器：

class ThemesController < ApplicationController
    def index
        @themes = Theme.all
    end
    def show
        @theme = Theme.find(params[:id])
        @current_sub = Subscription.where(:user_id => current_user.id, :theme_id => @theme.id)
    end

private
def theme_params
        params.require(:theme).permit(:name)
     end
end

更新这可能不是最佳选择，但我通过将控制器更改为：

来修复我的代码

def destroy
    @theme = Theme.find(params[:theme_id])
    @subscription = Subscription.where(:user_id => current_user.id, :theme_id => @theme.id)
    @subscription.destroy_all
    flash[:notice] = "You have unsubscribed to #{@theme.name}"
    redirect_to root_path
end

并查看传递“Unsubscribe Link”的不同参数：

<h1>QUOTES, YO.</h1>
<br>
<h3>
<% if @current_subs.count == 0 %>
<%= link_to "Subscribe!", new_subscription_path(:user_id => current_user.id, :theme_id => @theme.id, data: { confirm: 'Are you sure you want to subscribe?' } )%>
<% else %>
<%= button_to "UnSubscribe!", subscription_path(:user_id => current_user.id, :theme_id => @theme.id), :method => :delete, data: { confirm: 'Are you sure you want to unsubscribe?' } %>
<% end %>
</h3>
<br>
<% @theme.inspirations.each do |i| %>
    <%= i.quote %>
    <br>
<% end %>
<br>
<%= link_to "Back to Main", root_path %>

我不会对我如何调用@ subscription.destroy_all感到欣喜若狂，因为在用户和主题之间确实应该只有一个订阅实例，但它现在正在工作。

Answer 1

看到这一行？

 <%= button_to "UnSubscribe!", subscription_path(@current_sub), :method => :delete, data: { confirm: 'Are you sure you want to unsubscribe?' } %>

您没有提及主题或theme_id，因此您需要这样做：

<%= button_to "UnSubscribe!", subscription_path(@current_sub, :theme_id => @theme.id) :method => :delete, data: { confirm: 'Are you sure you want to unsubscribe?' } %>

这将传回theme_id，所以现在你可以在控制器中正确使用它了。

找不到没有ID的“模型”

1 个答案: