RoR select_tag默认值和选项

Question

如何使用设置默认值select_tag,如何在页面加载时保持选项打开？

Answer 1

如果您在select_tag没有任何其他帮助程序的情况下使用,那么您可以在html中执行此操作:

select_tag "whatever", "<option>VISA</option><option selected=\"selected\">MasterCard</option>"

或者options_for_select:

select_tag "whatever", options_for_select([ "VISA", "MasterCard" ], "MasterCard")

或者options_from_collection_for_select:

select_tag [SELECT_FIELD_NAME], options_from_collection_for_select([YOUR_COLLECTION], [NAME_OF_ATTRIBUTE_TO_SEND], [NAME_OF_ATTRIBUTE_SEEN_BY_USER], [DEFAULT_VALUE])

示例来自select_tagdoc,options_for_selectdoc和options_from_collection_for_selectdoc.

Answer 2

尝试这个：

<%= select_tag(:option, options_for_select([["Option 1",1],["Option 2",2],["Option 3",3]], params[:option] ), class:"select") %>

在 Rails 5 中效果很好。