将内插的 html 标记解释为 html，而不是字符串文字？

Question

我正在尝试将 HTML 标记 <br> 解释为换行符，但当我尝试这样做时它在视图中显示为字符串文字：

<%= property.address_line_2 + "<br>" if property.address_line_2.present? %>

我试过raw() and .html_safe但效果一样。

<%= property.address_line_2 + raw("<br>") if property.address_line_2.present? %>

<%= property.address_line_2 + "<br>".html_safe if property.address_line_2.present? %>

是否有 elegant/idiomatic 方法可以做到这一点，或者使用另一条线是最好的方法吗？我认为这种方法不是那么干：

<%= property.address_line_2 if property.address_line_2.present? %>
<% if property.address_line_2.present? %><br><% end %>

Answer 1

我会用

<% if property.address_line_2.present? %>
  <%= property.address_line_2 %><br>
<% end %>

这还有一个额外的好处，那就是更容易阅读

Answer 2

html_safe 必须返回字符串才能使标签不被转义：

<%= "<br>".html_safe %>

当 html_safe 字符串（又名 ActiveSupport::SafeBuffer）连接到常规字符串（又名 String）时，结果是常规未转义的字符串：

>> "<br>".html_safe.class
=> ActiveSupport::SafeBuffer
>> ("address" + "<br>".html_safe).class
=> String
>> ("address" + "<br>".html_safe).html_safe?
=> false

raw 只是一个辅助方法，做同样的事情，但首先调用 to_s：.to_s.html_safe

>> include ActionView::Helpers::OutputSafetyHelper
>> ("address" + raw("<br>")).html_safe?
=> false
>> raw("address" + "<br>").html_safe?
=> true

# NOTE: this doesn't work
>> ("address".html_safe + "<br>").html_safe?
=> true
# but the tag is escaped
>> "address".html_safe + "<br>"
=> "address&lt;br&gt;"

如果您必须将标签连接为字符串，请将整个结果标记为 html 安全：

<%= (property.address_line_2 + "<br>").html_safe %>

<%= property.address_line_2.html_safe + "<br>".html_safe %>

<%= raw(property.address_line_2 + "<br>") %>

<%== property.address_line_2 + "<br>" %>

如果您不想冒险使整个字符串安全，但仍想添加标签，请使用 safe_join 帮助程序：

<%= safe_join [property.address_line_1, "<br>".html_safe] %>

一次完成整个地址：

<% address_1 = "1st Street NE"; address_2 = " "; address_3 = nil; city = "City"; state = "Sate"; country = "Country" %>

<%=
  safe_join(
    [
      address_1,
      address_2,
      address_3,
      [city, state].join(", "),
      country
    ].reject(&:blank?),
    tag.br
  )
%>

# returns html safe string
"1st Street NE<br>City, Sate<br>Country"

# and renders
1st Street NE
City, Sate
Country

也只使用简单的 erb:

<% if (line = property.address_line_1.presence) %>
  <%= line %>
  <br>
<% end %>

https://api.rubyonrails.org/classes/String.html#method-i-html_safe

https://api.rubyonrails.org/classes/ActionView/Helpers/OutputSafetyHelper.html#method-i-raw

https://api.rubyonrails.org/classes/ActionView/Helpers/OutputSafetyHelper.html#method-i-safe_join

https://api.rubyonrails.org/classes/ActionView/Helpers/TagHelper.html#method-i-tag

将内插的 html 标记解释为 html，而不是字符串文字？

Interpret interpolated html tag as html, not string literal?

ruby-on-rails

ruby