content_for与部分收益率 [英] content_for vs yield in partials

问题描述

在具有HAML(3.1.4)的rails 3.0中

In rails 3.0 with HAML (3.1.4) I have

1. 一些类似模板的 partial ，例如_template.html.haml:

1. some template-like partial, like _template.html.haml:

.panel.top
  = yield :panel_top

.content
  = yield

另外一个 partial ，它将使用上一个模板显示(所有这些内容都是使用AJAX呈现的，但这无关紧要)

some another partial which will be displayed using prev template (all this stuff is rendered using AJAX, but this doesn't matter)

- content_for :panel_top do
 .title.left
   = title

content text

这在Rails 3.0

但是，升级到 3.2 后，此操作将失败！ Yiels只会产生内容文字"，所以我有两次内容文字"，根本没有标题

But, after upgrade to 3.2 this fails! Yiels just yields "content text", so I have "content text" twice and no title at all

仅将= yield :panel_top更改为= content_for :panel_top适用于3.2

only changing = yield :panel_top to = content_for :panel_top works for 3.2

我不确定该解决方案是否可行，如果它是稳定的或推荐使用的，我找不到有关yield处理，Rails 3.1发行说明和3.2发行说明中更改的任何注释.

I am not sure that this solution is ok, and if it is stable or recommended, I cannot find any notes about changes in yield processing nor in Rails 3.1 release notes, nor in 3.2 ones.

您能帮忙组织内部零件的最佳方法吗?

Can you help what is the best way to organize yielding inside partials?

推荐答案

从Rails 3.0到Rails 3.2 content_for确实已更改:

From Rails 3.0 to Rails 3.2 content_for was really changed:

3.0 :

def content_for(name, content = nil, &block)
    content = capture(&block) if block_given?
    @_content_for[name] << content if content
    @_content_for[name] unless content
end

3.2 :

def content_for(name, content = nil, &block)
  if content || block_given?
    content = capture(&block) if block_given?
    @view_flow.append(name, content) if content
    nil
  else
    @view_flow.get(name)
  end
end

这向我们展示了3.2 content_for中的版本也可以显示/插入内容，不仅将其存储在命名节中.

This shows us, that from 3.2 content_for works for showing/inserting content too, not only store it for named section.

此外，如果您尝试调试yield逻辑，则会发现它会在content_for正确初始化之前产生.

Also, if you make an attempt to debug yield logic you'll se that it yields before content_for is correctly initialized.

因此，将片段缓存排除在讨论之外，我可以得出结论，content_for是更可取的方式，可以在顶级布局之外的任何位置插入命名节.在助手和其他情况下，yield应该导致错误的结果.

So, leaving fragment caching out of this discussion I can conclude that content_for is preferrable way to insert named sections anywhere except top-level layouts. In helpers and other situations yield should render wrong results.

这篇关于content_for与部分收益率的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！