rails erb form helper options_for_select :selected

问题

I have an edit form in erb.

<%= form_for @animal do |f| %>

Within the code I have a select with options:

<%= f.select :gender, options_for_select([['Mare'], ['Stallion'], ['Gelding']], :selected => :gender) %>

However, the select is not showing the correct selected value. What could I be doing wrong? I can get it to work if I hardcode it but of course that is not a viable option.

回答1:

In your code, your options_for_select() call sets the selected value to "gender" and does not attempt to use the value from your form object.

Please see the docs for options_for_select() for usage examples.

options_for_select(['Mare', 'Stallion', 'Gelding'], f.object.gender)
options_for_select(['Mare', 'Stallion', 'Gelding'], :selected => f.object.gender)

Alternatively, you can do this, which will already use the gender() value for your form object:

<%= f.select :gender, ['Mare', 'Stallion', 'Gelding'] %>

回答2:

By the way, if you are using :include_blank => true, this will set your current selection to blank even though the form "knows" what is selected.

来源：https://stackoverflow.com/questions/19120706/rails-erb-form-helper-options-for-select-selected