Ruby-on-rails local_assigns 在 Rails 中是如何工作的？
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How does local_assigns work in Rails?
提问by Lee McAlilly
I've been googling around about this and can't find the right path. I'm working on a Rails app that is using a method called local_assigns. This appears to be something in Rails or a gem, and not specific to my app, but it's used for rendering a partial in different contexts, such as this:
我一直在谷歌上搜索这个，但找不到正确的路径。我正在开发一个使用名为 local_assigns 的方法的 Rails 应用程序。这似乎是 Rails 或 gem 中的东西，并不特定于我的应用程序，但它用于在不同的上下文中呈现部分，例如：
<% if local_assigns[:custom_name] %>
<li><%= custom_name %></li>
<% else %>
or also this:
或者这个：
<%= render "discussions/complementary/#{local_assigns[:action] || params[:action]}" %>
Is this is Rails method? Where can I find more documentation about this?
这是 Rails 方法吗？我在哪里可以找到更多关于此的文档？
回答by Chamnap
local_assignsis a Rails view helper method that you can check whether this partial has been provided with local variables or not.
local_assigns是一个 Rails 视图助手方法，您可以检查此部分是否已提供局部变量。
Here you render a partial with some values, the headlineand personwill become accessible with predefined value.
在这里，您使用一些值渲染部分，headline和person将通过预定义的值变得可访问。
<%= render "shared/header", { :headline => "Welcome", :person => person } %>
In shared/headerview:
在shared/header视图：
Headline: <%= headline %>
First name: <%= person.first_name %>
Here is how you check these variables has passed in or not:
以下是检查这些变量是否传入的方法：
<% if local_assigns.has_key? :headline %>
Headline: <%= headline %>
<% end %>
Check this document for more detail on the section Passing local variables to sub templates.
有关将局部变量传递给子模板部分的更多详细信息，请查看此文档。
