Question

我在使用bootstrap_flash帮助程序进行闪烁时遇到了困难。这是我的代码片段：

application.html.erb

...
<div class="container">
  <%= bootstrap_flash  %>
  <%= yield %> 
</div>
...

bootstrap_flash_helper.rb

ALERT_TYPES = [:error, :info, :success, :warning] unless const_defined?(:ALERT_TYPES)

def bootstrap_flash
  flash_messages = []
  flash.each do |type, message|
    # Skip empty messages, e.g. for devise messages set to nothing in a locale file.
    next if message.blank?

    type = type.to_sym
    type = :success if type.to_s == :notice.to_s
    type = :error   if type.to_s == :alert.to_s
    next unless ALERT_TYPES.include?(type)

    Array(message).each do |msg|
      text = content_tag(:div, content_tag(:button, raw("&times;"), :class => "close", "data-dismiss" => "alert") + msg.html_safe, :class => "alert fade in alert-#{type}")
      flash_messages << text if msg
    end
  end
    flash_messages.join("\n").html_safe
end
end

我正在控制器操作中调用flash [：notice]。

有人可以给我一个暗示吗？谢谢！

Answer 1

乍一看，代码中的最后一个end太多了。

乍一看，我认为您的代码存在一些缺陷：

（1）避免来回投射：

type = type.to_sym
type = :success if type.to_s == :notice.to_s
type = :error   if type.to_s == :alert.to_s

您将type转换为符号，仅将其强制转换为字符串，同时将常量符号转换为字符串以进行比较。如果省略to_s次调用，则可以实现相同的操作而无需强制转换：

type = type.to_sym
type = :success if type == :notice
type = :error   if type == :alert

（2）使用map代替辅助变量+ each：

flash_messages = []
flash.each do |type, message|
  # ...
end
flash_messages.join("\n")

您可以使用Enumerable的{{3}}或map方法创建新数组，而不是创建临时变量来将哈希转换为数组：

flash.map do |type, message|
  # ...
end.join("\n")

（3）使用映射哈希映射到CSS类：

ALERT_TYPES = {
 :alert => :error, :info => :info, :notice => :success, :warning => :warning
}

通过使用这样的哈希，您只需查找匹配项，而不是使用多个if语句来确定正确的类

content_tag(:div, message, class: "alert alert-#{ALERT_TYPES[type.to_sym]}")

总的来说，我认为这将是一个更具可读性，更短和可扩展的解决方案：

ALERT_TYPES = { :alert => :error, :info => :info, :notice => :success, :warning => :warning } unless const_defined?(:ALERT_TYPES)

def bootstrap_flash
  flash.map do |type, message|
    # Skip empty messages, e.g. for devise messages set to nothing in a locale file.
    # This will leave a nil value in the resulting array
    next if message.blank?

    # Skip if it's not a valid alert type
    # This will leave a nil value in the resulting array
    type = type.to_sym
    next unless ALERT_TYPES.keys.include?(type)

    # return the markup for the alert
    content_tag(:div, class: "alert alert-#{ALERT_TYPES[type]} fade in") do
      # use safe_concat() to avoid using html_safe()
      content_tag(:button, raw("&times;"), class: "close", data: { dismiss: "alert" }).safe_concat(message)
    end
  end.join('') # no need to join with \n --> this way nil values will be ignored as well
end

bootstrap flash不适用于rails 4.1.4和simple_form

1 个答案: