Question

将应用程序从Rails 4.2.9迁移到5.2.1。

这是最新一期：

$ rails console
/Users/meltemi/rails/myapp/config/initializers/disable_xml_params.rb:3:in `<top (required)>': uninitialized constant ActionDispatch::ParamsParser (NameError)
    from /Users/meltemi/.rbenv/versions/2.4.4/lib/ruby/gems/2.4.0/gems/railties-5.2.1/lib/rails/engine.rb:657:in `block in load_config_initializer'
    from /Users/meltemi/.rbenv/versions/2.4.4/lib/ruby/gems/2.4.0/gems/activesupport-5.2.1/lib/active_support/notifications.rb:170:in `instrument'
    from /Users/meltemi/.rbenv/versions/2.4.4/lib/ruby/gems/2.4.0/gems/railties-5.2.1/lib/rails/engine.rb:656:in `load_config_initializer'

初始化程序中令人反感的代码行：

# config/initializers/disable_xml_params.rb
ActionDispatch::ParamsParser::DEFAULT_PARSERS.delete(Mime::XML)

Rails Guides说：

ActionDispatch :: ParamsParser已过时，并已从中间件堆栈中删除。要配置参数解析器，请使用ActionDispatch :: Request.parameter_parsers =。（提交，提交）

所以我尝试了以下方法：

ActionDispatch::Request.parameter_parsers.delete(Mime::XML)

但这会引发更多错误：

$ rails console
/Users/meltemi/rails/myapp/config/initializers/disable_xml_params.rb:3:in `<top (required)>': uninitialized constant Mime::XML (NameError)
    from /Users/meltemi/.rbenv/versions/2.4.4/lib/ruby/gems/2.4.0/gems/railties-5.2.1/lib/rails/engine.rb:657:in `block in load_config_initializer'
    from /Users/meltemi/.rbenv/versions/2.4.4/lib/ruby/gems/2.4.0/gems/activesupport-5.2.1/lib/active_support/notifications.rb:170:in `instrument'
    from /Users/meltemi/.rbenv/versions/2.4.4/lib/ruby/gems/2.4.0/gems/railties-5.2.1/lib/rails/engine.rb:656:in `load_config_initializer'

是否有更好的方法在该对象上调用.delete？

Answer 1

您必须从parameter_parsers获取现有值，对其进行修改以适合您的需要，然后将这些值重置为修改后的值。来自ActionDispatch::Http::Parameters documentation：

parameter_parsers=(parsers)

为给定的MIME类型配置参数解析器。

它接受一个散列，其中的键是MIME类型的符号，而值是proc。

original_parsers = ActionDispatch::Request.parameter_parsers
xml_parser = -> (raw_post) { Hash.from_xml(raw_post) || {} }
new_parsers = original_parsers.merge(xml: xml_parser)
ActionDispatch::Request.parameter_parsers = new_parsers

在特定情况下，您应该查看original_parsers中的解析器，以查看是否有任何要删除的内容。在我方便查看的简单Rails 5应用程序上，我仅有的值是：

=> {
    :json => #<Proc:0x00007fe818fc6fb8@/Users/foo/.rvm/gems/ruby-2.6.0-preview2/gems/actionpack-5.2.1/lib/action_dispatch/http/parameters.rb:11 (lambda)>
}

您的应用程序的配置可能有所不同，但是要回答有关如何删除值的问题，此简单版本应该可以工作：

ActionDispatch::Request.parameter_parsers = ActionDispatch::Request.parameter_parsers.except(:json)

您可能会找到其他有用的信息in this answer。

升级到Rails 5后替换ActionDispatch :: ParamsParser

1 个答案: