app/views/shared/_crop_button.html.erb
<%= button(:image, _('Add image'), '#', :id => 'add-cropped-image') %>
<div class='file-fieldset'>
<%= file_field_tag('crop[file]',
:class => 'picture-input',
:accept => "image/*",
:onChange => 'cropImage(this)') %>
<%= render :partial => 'shared/cropped_image_preview', :locals => { :image => nil, :type => 'default' } %>
<%= render :partial => 'shared/crop_image_form',
:locals => { :for_attr => 'crop'} %>
</div>