Render 与 Render Partial 和 Yield 之间的区别 [英] Difference between Render and Render Partial and Yield
问题描述
我从 Rails 指南中读过，看过 Micheal Hartel 的书，现在从 Rails View 中读过，但我仍然感到困惑:(
有一个 _footer.html.erb 文件，所以它是一个部分"文件，在它编写的代码中:
<%=render 'layouts/footer' %>所以我的理解是，当它看到这一点时，会在此处插入页脚文件的 HTML.好的...现在几页后它说:
<%= 渲染部分:'activitiy_items/recent' %>那么为什么这次我们在这里有部分"这个词，而在上一次没有呢?
在其他地方我看到 <%= yield :sidebar %>
所以这个 yield 也在它的位置插入了 HTML?嗯，这不是 render 正在做的吗?
我希望如果另一个程序员而不是书籍向我解释这一点，也许这次我明白了:)
render &渲染部分:
render 'some_view'是render partial: 'some_view'的简写.render file: 'view'将查找文件view.html.erb而不是_view.html.erb(.erb或您使用的任何其他渲染器)render不会接受额外的局部变量，你需要使用render partial:如下:render partial: 'some/path/to/my/partial', locals: { custom_var: 'Hello' }
(http://guides.rubyonrails.org/layouts_and_rendering.html#passing-本地变量)
产量 &content_for
yield通常用于布局.它告诉 Rails 将此块的内容放在布局中的那个位置.- 当您执行与
content_for :something相关联的yield :something时，您可以传递一个代码块(视图)来显示yield :something被放置(见下面的例子).
一个关于收益的小例子:
在您的布局中:
<头><%=产量:html_head %><身体><div id="侧边栏"><%=产量:侧边栏%>在您看来:
<% content_for :sidebar do %>此内容将显示在侧边栏部分<%结束%><% content_for :html_head do %><script type="text/javascript">console.log("Hello World!");<%结束%>这将生成以下 HTML:
<头><script type="text/javascript">console.log("Hello World!");<身体><div id="侧边栏">此内容将显示在侧边栏部分<小时>
可能有帮助的帖子:
链接到文档和指南:
- http://guides.rubyonrails.org/layouts_and_rendering.html#passing-局部变量
- http://apidock.com/rails/ActionView/Helpers/CaptureHelper/content_for
- http://apidock.com/rails/ActionController/Base/render
I have read it from the Rails guides, Have looked at Micheal Hartel book and now reading it from Rails View book but still I get confused :(
There is a _footer.html.erb file so it is a "partial" and in the code it has written:
<%=render 'layouts/footer' %>
so my understanding is that when it sees this, goes and insert the HTML for footer file in here. Ok... Now a few pages later it is saying:
<%= render partial: 'activitiy_items/recent' %>
so WHY this time we have the word "partial" in here but we didn't have it in the previous one?
And there somewhere else I see <%= yield :sidebar %>
So this yield also insert HTML in its place? Well wasn't it what render was doing?
I was hoping if another programmer instead of books explains this to me maybe I get it this time:)
render & render partial:
render 'some_view'is a shorthand forrender partial: 'some_view'.render file: 'view'will look for a fileview.html.erband NOT_view.html.erb(.erbor any other renderer you use)renderwill not accept additional local variables for the partial, you need to userender partial:as following for that:render partial: 'some/path/to/my/partial', locals: { custom_var: 'Hello' }
(http://guides.rubyonrails.org/layouts_and_rendering.html#passing-local-variables)
yield & content_for
yieldis typically used in layouts. It tells Rails to put the content for this block at that place in the layout.- When you do
yield :somethingassociated withcontent_for :something, you can pass a block of code (view) to display where theyield :somethingis placed (see example below).
A small example about yield:
In your layout:
<html>
<head>
<%= yield :html_head %>
</head>
<body>
<div id="sidebar">
<%= yield :sidebar %>
</div>
</body>
In one of your view:
<% content_for :sidebar do %>
This content will show up in the sidebar section
<% end %>
<% content_for :html_head do %>
<script type="text/javascript">
console.log("Hello World!");
</script>
<% end %>
This will produce the following HTML:
<html>
<head>
<script type="text/javascript">
console.log("Hello World!");
</script>
</head>
<body>
<div id="sidebar">
This content will show up in the sidebar section
</div>
</body>
Posts that might help:
Links to documentation & guides:
- http://guides.rubyonrails.org/layouts_and_rendering.html#passing-local-variables
- http://apidock.com/rails/ActionView/Helpers/CaptureHelper/content_for
- http://apidock.com/rails/ActionController/Base/render
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