如何避免在select2 gem中选择提示

Question

I have used select2-rails gem. When it is applied, the prompt is also selectable. How to avoid prompt as selected?

Answer 1

You can also do something like this on the element without having to specify placeholder in Javascript.

<%= f.collection_select :method, Model.all, :id, :name,
{include_blank: true}, data: {placeholder: 'Choose Model'}, class:
"select2"%>

assuming you have initialized this element with select2 somewhere in your javascript files.

Answer 2

使用'placeholder'选项，如下所示：

$(element).select2(placeholder: 'select one option', ** other options here);

Answer 3

IN YOURVIEW.HTML.SLIM

select.form-control#js__multiselect multiple="multiple" name='your_name[]' value="#{params[:your_value]}"
  = options_from_collection_for_select(Model.all, :id, :value, params[:your_params])

# :id, :value are what values you want to show from your Model.
# params[:your_params], which is array is your selected value.