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# File action_view/helpers/form_options_helper.rb, line 406 def add_options(option_tags, options, value = nil) if options[:include_blank] option_tags = "<option value=\"\">#{options[:include_blank] if options[:include_blank].kind_of?(String)}</option>\n" + option_tags end if value.blank? && options[:prompt] ("<option value=\"\">#{options[:prompt].kind_of?(String) ? options[:prompt] : 'Please select'}</option>\n") + option_tags else option_tags end end
<code/>and<pre/>for code samples.