Ruby-on-rails Rails 表单（选择/选项）-如何使用 HAML 标记选定的选项？
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Rails form (select/option) - how to mark selected option with HAML?
提问by user984621
What's the quickest and most elegant way to mark currently selected option value in the form in HAML?
在 HAML 的表单中标记当前选择的选项值的最快和最优雅的方法是什么？
%form{:action => '', :method => 'get'}
%select{:name => 'param_name'}
%option{:value => 'A'} A data
%option{:value => 'B'} B data
One way:
单程：
- if params[:param_name] == "A"
%option{:value => 'A', :selected => 'selected'} A data
- else
%option{:value => 'A'} A data
but this is inappropriate when the selectbox will has many option fields...
但是当select框有很多选项字段时这是不合适的......
回答by egze
Something like this will work (using the older "hashrocket syntax" with the operator =>)
像这样的东西会起作用（将旧的“hashrocket 语法”与操作符一起使用=>）
%select
%option{:value => "a", :selected => params[:x] == "a"}= "a"
%option{:value => "b", :selected => params[:x] == "b"}= "b"
Or, in newer Ruby versions (1.9 and greater):
或者，在较新的 Ruby 版本（1.9 及更高版本）中：
%select
%option{value: "a", selected: params[:x] == "a"}= "a"
%option{value: "b", selected: params[:x] == "b"}= "b"
回答by Mik
You should unleash the power of rails helpers.
你应该释放 rails helpers 的力量。
= select_tag :param_name, options_for_select([['A data', 'A'], ['B data', 'B']], params[:param_name])
Also, instead of raw %formuse form_tagor better form_forwhen it's possible (or more better simple_form or formtastic)
此外，在可能的情况下，不要%form使用原始使用form_tag或更好form_for（或更好的 simple_form 或 formtastic）
