我按照 Ryan Bates 教程实现了这个sort table columns
并且效果很好,但是当我呈现索引页面时,表格已经按标题(asc)排序,我只想在用户单击列标题时对列进行排序。
我怎么能做到这一点?
代码
控制器
class ProductsController < ApplicationController
helper_method :sort_column, :sort_direction
def index
@products = Product.order(sort_column + " " + sort_direction)
end
# ...
private
def sort_column
Product.column_names.include?(params[:sort]) ? params[:sort] : "name"
end
def sort_direction
%w[asc desc].include?(params[:direction]) ? params[:direction] : "asc"
end
end
helper_method
def sortable(column, title = nil)
title ||= column.titleize
css_class = column == sort_column ? "current #{sort_direction}" : nil
direction = column == sort_column && sort_direction == "asc" ? "desc" : "asc"
link_to title, {:sort => column, :direction => direction}, {:class => css_class}
end
index.html.erb
<tr>
<th><%= sortable "name" %></th>
<th><%= sortable "price" %></th>
<th><%= sortable "released_at", "Released" %></th>
</tr>
CSS
.pretty th .current {
padding-right: 12px;
background-repeat: no-repeat;
background-position: right center;
}
.pretty th .asc {
background-image: url(/images/up_arrow.gif);
}
.pretty th .desc {
background-image: url(/images/down_arrow.gif);
}