Question

我正在使用以下内容使用户能够按日期（ASC），日期（DESC）和投票对评论进行排序：

posts_controller.rb：

  def show
    @post = Post.find(params[:id])
    @comments = @post.comments.paginate(:page => params[:page],
                                        :per_page => 5).order(params[:order_by])
    @comment = @post.comments.build
  end

视图/帖/ show.html.erb：

<div class="comments-tabs">
  <span><%= link_to 'Votes', post_path(@post, :order_by => "total_votes DESC") %></span>
  <span><%= link_to 'Date (ASC)', post_path(@post, :order_by => "created_at ASC") %></span>
  <span><%= link_to 'Date (DESC)', post_path(@post, :order_by => "created_at DESC") %></span>
</div>

网址最终看起来像这样：

http://localhost:3000/posts/59?order_by=total_votes+DESC
http://localhost:3000/posts/59?order_by=created_at+ASC
http://localhost:3000/posts/59?order_by=created_at+DESC

我想创建一个if语句来向当前标签添加一个类。例如：

    http://localhost:3000/posts/59?order_by=created_at+ASC


  <span class="comment-tab"><%= link_to 'Votes', post_path(@post, :order_by => "total_votes DESC") %></span>
  <span class="comment-tab current"><%= link_to 'Date (ASC)', post_path(@post, :order_by => "created_at ASC") %></span>
  <span class="comment-tab><%= link_to 'Date (DESC)', post_path(@post, :order_by => "created_at DESC") %></span>

Answer 1

你可以使用current_page吗？确定用户是否正在查看某个页面并根据该页面应用html类的方法。

以下是一个例子：

 %ul
    %li{:class => "#{current_page?(root_path) ? "selected" : ""}"}= link_to content_tag(:span, "Home"), root_path
    %li{:class => "#{current_page?(birth_certificate_path) ? "selected" : ""}"}= link_to content_tag(:span, "Birth Certificates"), birth_certificate_path
    %li{:class => "#{current_page?(marriage_certificate_path) ? "selected" : ""}"}= link_to content_tag(:span, "Marriage Certificates"), marriage_certificate_path
    %li{:class => "#{current_page?(death_certificate_path) ? "selected" : ""}"}= link_to content_tag(:span, "Death Certificates"), death_certificate_path

Answer 2

查看rails api

的link_to_unless_current方法

<%=
    link_to_unless_current("Comment", { :controller => "comments", :action => "new" }) do
       link_to("Go back", { :controller => "posts", :action => "index" })
    end
 %>

Answer 3

这是一个很好的问题。你真让我思考。我想在我自己的项目中完成类似的事情，重构一些臭的if语句，当它的包含链接等于当前页面时用于设置div或li的样式。

我用咖啡味的jQuery写了这个。试一试。

应用程序/资产/ Javascript角/ current_tab.js.coffee

$(document).ready ->
  $('.comment-tab').each ->
    if $(this).children('a').first().attr('href') is window.location.href
      $(this).addClass('current')

在视图中将post_path更改为post_url，它应该可以正常工作。

应用程序/视图/帖/ show.html.haml

.comments-tabs
  %span= link_to 'Votes',       post_url(@post, order_by: 'total_votes DESC')
  %span= link_to 'Date (ASC)',  post_url(@post, order_by: 'created_at ASC')
  %span= link_to 'Date (DESC)', post_url(@post, order_by: 'created_at DESC')

Answer 4

<div class="comments-tabs">
  <span><%= link_to 'Votes', post_path(@post, :order_by => "total_votes DESC"), {}, {:class => "#{params[:order_by] == 'total_votes+DESC' ? 'comment_tab current' : 'comment_tab'}"} %></span>
  <span><%= link_to 'Date (ASC)', post_path(@post, :order_by => "created_at ASC"), {}, {:class => "#{params[:order_by] == 'created_at+ASC' ? 'comment_tab current' : 'comment_tab'}"}  %></span>
  <span><%= link_to 'Date (DESC)', post_path(@post, :order_by => "created_at DESC"), {}, {:class => "#{params[:order_by] == 'created_at+DESC' ? 'comment_tab current' : 'comment_tab'}"} %></span>
</div>

未测试。

如何使用以下URL参数构建if语句？

4 个答案: