Rails显示嵌套层次结构视图的方式是什么？似乎是一个简单的问题，但试着忍受我，也许有人会理解（并希望能消除）我的困惑。
我的应用程序是一个简单的层次结构（为了讨论的目的而更加简化）：
很简单，但我的问题是 Rails 的方式是什么：
我问一些看似如此基本的问题的原因是，从第一次单击开始，我正在查看“文档”（）以及其中包含document#show的章节（ ）。那么，视图应该建立在chapters#index两者中的哪一个？
与我正在查看章节开头的下一次单击相同。那可能是chapters#showorpages#index动作。不过，可以想象，我猜它也可以（并且也许应该）由pages#show.
想法？我是不是想太多了？（可能）
You can set up your routes like this to take advantage of Rails' built in nested resources:
resources :documents, :only => [:index, :show] do
resources :chapters, :only => :show do
resources :pages, :only => :show
end
end
This is roughly equivalent to setting up these custom routes:
get '/documents' => 'documents#index',
:as => 'documents'
get '/documents/:id' => 'documents#show',
:as => 'document'
get '/documents/:document_id/chapters/:id' => 'chapters#show',
:as => 'document_chapter'
get '/documents/:document_id/chapters/:chapter_id/pages/:id' => 'pages#show',
:as => 'document_chapter_page'
If the URLs are a little longer and more cumbersome than you had hoped for, or you want to use custom parameters (e.g. identifying pages by number and not by ID), you can always write custom routes instead:
resources :documents, :only => [:index, :show]
get '/documents/:document_id/:id' => 'chapters#show',
:as => 'document_chapter'
get '/documents/:document_id/:chapter_id/:page' => 'pages#show',
:as => 'document_chapter_page'
See the routing guide for more information.
You don't want a user to be able to visit a chapter directly, instead they should see the first page of the chapter. However, it's arguably useful for chapter URLs to work without a page number (especially if page numbers refer to the position in a document and not the position in a chapter).
You could therefore redirect from the chapters controller's show action to the first page:
class ChaptersController < ApplicationController
def show
chapter = Chapter.find(params[:id])
redirect_to [chapter.document, chapter, chapter.pages.first]
end
end
There are two approaches you could take to sharing the list of chapters between different views:
Use Rails' built in support for rendering a collection of model objects. In your views/documents/show.html.erb and views/chapters/show.html.erb you can include something like the following (I'm assuming each action sets a @document variable):
<ol>
<%= render @document.chapters %>
</ol>
Rails will look for a partial view called views/chapters/_chapter.html.erb, and render it for each of the chapters. It could look like this:
<li><%= link_to chapter, [chapter.document, chapter] %></li>
Share the whole list in a single partial. For example, you could add the following to views/documents/show.html.erb and views/chapters/show.html.erb:
<%= render 'chapters/list', :chapters => @document.chapters %>
And create a partial view called views/chapters/_list.html.erb:
<ol>
<% chapters.each do |chapter| %>
<li><%= link_to chapter, [chapter.document, chapter] %></li>
<% end %>
</ol>
See the section on Using Partials in the Layouts and Rendering guide for more information.
我不止一次地读过嵌套不应该被滥用，2 层显然很好，如果有意义的话，可以设置 3 层，但是任何超过 3 层的东西，你可能需要重新考虑。
您可以使用三层嵌套，即
/docs/:id/:chapter/:page
但这样做也可能有意义
/docs/:id/:page
即直接引用文档的一页，而不关心指定章节
如果章节是数字，页面是数字，您的路由将如何区分，即
/docs/1001/1
那是 doc 1001 的第 1 页吗？还是 doc 1001 的第 1 章？
只是扮演魔鬼的拥护者，当您尝试深入嵌套时，会显示出潜在的缺点。
我认为最自然的事情是：
'/docs' => 'docs#index' # show all docs
'/docs/:id' => 'docs#show' # show all chapters in a doc
'/docs/:id/chapter/:chpt' => 'docs#show_chapter' # show all pages in a chapter in a doc
'/docs/:id/:page' => 'docs#show' # show a page in a doc
the show actions would have:
if params[:page]
# show page specified
else
# show all chapters
end
the order of the routes is important
我推荐这个的原因是因为书籍/页面查询语义可能比书籍/章节/页面更常见。
这些关联将是：
class Doc < ActiveRecord::Base
has_many :pages
has_many :chapters
end
我不会在路由中公开 end_page，我只会在任何接受 :page 的路由上添加 '?endpage=X'，例如在 show 操作中：
if params[:page]
if params[:end_page]
# show pages :page through :end_page
else
# show single :page
end
else
# show all chapters
end