Class: Formtastic::Inputs::SelectInput

Inherits:
Object
  • Object
show all
Includes:
Base, Base::Collections, Base::GroupedCollections
Defined in:
lib/formtastic/inputs/select_input.rb

Overview

A select input is used to render a ‘<select>` tag with a series of options to choose from. It works for both single selections (like a `belongs_to` relationship, or “yes/no” boolean), as well as multiple selections (like a `has_and_belongs_to_many`/`has_many` relationship, for assigning many genres to a song, for example).

This is the default input choice when:

  • the database column type is an ‘:integer` and there is an association (`belongs_to`)

  • the database column type is a ‘:string` and the `:collection` option is used

  • there an object with an association, but no database column on the object (‘has_many`, etc)

  • there is no object and the ‘:collection` option is used

The flexibility of the ‘:collection` option (see examples) makes the :select input viable as an alternative for many other input types. For example, instead of…

  • a ‘:string` input (where you want to force the user to choose from a few specific strings rather than entering anything)

  • a ‘:boolean` checkbox input (where the user could choose yes or no, rather than checking a box)

  • a ‘:date`, `:time` or `:datetime` input (where the user could choose from pre-selected dates)

  • a ‘:number` input (where the user could choose from a set of pre-defined numbers)

  • a ‘:time_zone` input (where you want to provide your own set of choices instead of relying on Rails)

  • a ‘:country` input (no need for a plugin really)

Within the standard ‘<li>` wrapper, the output is a `<label>` tag followed by a `<select>` tag containing `<option>` tags.

For inputs that map to associations on the object model, Formtastic will automatically load in a collection of objects on the association as options to choose from. This might be an ‘Author.all` on a `Post` form with an input for a `belongs_to :user` association, or a `Tag.all` for a `Post` form with an input for a `has_and_belongs_to_many :tags` association. You can override or customise this collection and the `<option>` tags it will render through the `:collection` option (see examples).

The way on which Formtastic renders the ‘value` attribute and content of each `<option>` tag is customisable through the `:label_method` and `:value_method` options. When not provided, we fall back to a list of methods to try on each object such as `:to_label`, `:name` and `:to_s`, which are defined in the configurations `collection_label_methods` and `collection_value_methods` (see examples below).

Examples:

Basic ‘belongs_to` example with full form context


<%= semantic_form_for @post do |f| %>
  <%= f.inputs do %>
    <%= f.input :author, :as => :select %>
  <% end %>
<% end %>

<form...>
  <fieldset>
    <ol>
      <li class='select'>
        <label for="post_author_id">Author</label>
        <select id="post_author_id" name="post[post_author_id]">
          <option value=""></option>
          <option value="1">Justin</option>
          <option value="3">Kate</option>
          <option value="2">Amelia</option>
        </select>
      </li>
    </ol>
  </fieldset>
</form>

Basic ‘has_many` or `has_and_belongs_to_many` example with full form context


<%= semantic_form_for @post do |f| %>
  <%= f.inputs do %>
    <%= f.input :tags, :as => :select %>
  <% end %>
<% end %>

<form...>
  <fieldset>
    <ol>
      <li class='select'>
        <label for="post_tag_ids">Author</label>
        <select id="post_tag_ids" name="post[tag_ids]" multiple="true">
          <option value="1">Ruby</option>
          <option value="6">Rails</option>
          <option value="3">Forms</option>
          <option value="4">Awesome</option>
        </select>
      </li>
    </ol>
  </fieldset>
</form>

Override Formtastic’s assumption on when you need a multi select

<%= f.input :authors, :as => :select, :input_html => { :multiple => true } %>
<%= f.input :authors, :as => :select, :input_html => { :multiple => false } %>

The ‘:collection` option can be used to customize the choices

<%= f.input :author, :as => :select, :collection => @authors %>
<%= f.input :author, :as => :select, :collection => Author.all %>
<%= f.input :author, :as => :select, :collection => Author.some_named_scope %>
<%= f.input :author, :as => :select, :collection => [Author.find_by_login("justin"), Category.find_by_name("kate")] %>
<%= f.input :author, :as => :select, :collection => ["Justin", "Kate"] %>
<%= f.input :author, :as => :select, :collection => [["Justin", "justin"], ["Kate", "kate"]] %>
<%= f.input :author, :as => :select, :collection => [["Justin", "1"], ["Kate", "3"]] %>
<%= f.input :author, :as => :select, :collection => [["Justin", 1], ["Kate", 3]] %>
<%= f.input :author, :as => :select, :collection => 1..5 %>
<%= f.input :author, :as => :select, :collection => "<option>your own options HTML string</option>" %>
<%= f.input :author, :as => :select, :collection => options_for_select(...) %>
<%= f.input :author, :as => :select, :collection => options_from_collection_for_select(...) %>
<%= f.input :author, :as => :select, :collection => grouped_options_for_select(...) %>
<%= f.input :author, :as => :select, :collection => time_zone_options_for_select(...) %>

The ‘:label_method` can be used to call a different method (or a Proc) on each object in the collection for rendering the label text (it’ll try the methods like ‘to_s` in `collection_label_methods` config by default)

<%= f.input :author, :as => :select, :label_method => :name %>
<%= f.input :author, :as => :select, :label_method => :name_with_post_count
<%= f.input :author, :as => :select, :label_method => Proc.new { |a| "#{c.name} (#{pluralize("post", a.posts.count)})" }

The ‘:value_method` can be used to call a different method (or a Proc) on each object in the collection for rendering the value for each checkbox (it’ll try the methods like ‘id` in `collection_value_methods` config by default)

<%= f.input :author, :as => :select, :value_method => :login %>
<%= f.input :author, :as => :select, :value_method => Proc.new { |c| c.full_name.downcase.underscore }

Set HTML attributes on the ‘<select>` tag with `:input_html`

<%= f.input :authors, :as => :select, :input_html => { :size => 20, :multiple => true, :class => "special" } %>

Set HTML attributes on the ‘<li>` wrapper with `:wrapper_html`

<%= f.input :authors, :as => :select, :wrapper_html => { :class => "special" } %>

Exclude or include the blank option at the top of the select, or change the prompt

<%= f.input :author, :as => :select, :input_html => { :include_blank => false } %>
<%= f.input :author, :as => :select, :input_html => { :include_blank => true } %>
<%= f.input :author, :as => :select, :input_html => { :prompt => "Please select an Author..." } %>

Group options an ‘<optgroup>` with the `:group_by` and `:group_label_method` options (`belongs_to` associations only)

<%= f.input :author, :as => :select, :group_by => :continent %>

See Also:

Instance Attribute Summary

Attributes included from Base

#builder, #method, #object, #object_name, #options, #template

Instance Method Summary collapse

Methods included from Base::GroupedCollections

#group_association, #group_association_from_options, #group_association_from_reflection, #group_by, #group_label_method, #group_label_method_from_grouped_collection, #group_label_method_from_options, #grouped_collection, #raw_grouped_collection

Methods included from Base::Collections

#collection, #collection_for_boolean, #collection_from_association, #collection_from_options, #label_and_value_method, #label_method, #raw_collection, #send_or_call, #value_method

Methods included from Base

#initialize

Methods included from Base::Wrapping

#input_wrapping, #wrapper_dom_id, #wrapper_html_options

Methods included from Base::Labelling

#label_from_options, #label_html, #label_text, #localized_label, #render_label?, #requirement_text, #requirement_text_or_proc

Methods included from Base::Associations

#association, #association_primary_key, #belongs_to?, #reflection

Methods included from Base::Fileish

#file?

Methods included from Base::Validations

#column_limit, #limit, #not_required_through_negated_validation!, #not_required_through_negated_validation?, #optional?, #required?, #validation_integer_only?, #validation_limit, #validation_max, #validation_min, #validations, #validations?, #validator_relevant?

Methods included from Base::Naming

#as, #attributized_method_name, #humanized_method_name, #input_name, #sanitized_method_name, #sanitized_object_name

Methods included from Base::Hints

#hint?, #hint_html, #hint_text, #hint_text_from_options

Methods included from Base::Errors

#error_first_html, #error_html, #error_keys, #error_list_html, #error_none_html, #error_sentence_html, #errors, #errors?

Methods included from Base::Database

#column, #column?

Methods included from Base::Options

#formtastic_options

Methods included from Base::Html

#dom_id, #dom_index

Instance Method Details

#extra_input_html_options ⇒ Object 



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# File 'lib/formtastic/inputs/select_input.rb', line 183

def extra_input_html_options
  {
    :multiple => multiple_by_association?,
    :name => "#{object_name}[#{association_primary_key}]"
  }
end

#grouped_select_html ⇒ Object 



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# File 'lib/formtastic/inputs/select_input.rb', line 151

def grouped_select_html
  builder.grouped_collection_select(
    input_name, 
    grouped_collection,
    group_association, 
    group_label_method,
    value_method, 
    label_method,
    input_options, 
    input_html_options
  )
end

#include_blank? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/formtastic/inputs/select_input.rb', line 164

def include_blank?
  return options[:prompt] if options.key?(:prompt)
  return options[:include_blank] if options.key?(:include_blank)
  return true if (single? && builder.include_blank_for_select_by_default)
  false
end

#input_html_options ⇒ Object 



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# File 'lib/formtastic/inputs/select_input.rb', line 179

def input_html_options
  extra_input_html_options.merge(super)
end

#input_options ⇒ Object 



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# File 'lib/formtastic/inputs/select_input.rb', line 175

def input_options
  {:include_blank => include_blank?}.merge(super)
end

#label_html_options ⇒ Object 



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# File 'lib/formtastic/inputs/select_input.rb', line 171

def label_html_options
  super.merge(:for => input_html_options[:id])
end

#multiple? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/formtastic/inputs/select_input.rb', line 198

def multiple?
  multiple_by_options? || multiple_by_association? 
end

#multiple_by_association? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/formtastic/inputs/select_input.rb', line 190

def multiple_by_association?
  reflection && [ :has_many, :has_and_belongs_to_many ].include?(reflection.macro)
end

#multiple_by_options? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/formtastic/inputs/select_input.rb', line 194

def multiple_by_options?
  options[:multiple]
end

#select_html ⇒ Object 



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# File 'lib/formtastic/inputs/select_input.rb', line 147

def select_html
  builder.select(input_name, collection, input_options, input_html_options)
end

#single? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/formtastic/inputs/select_input.rb', line 202

def single?
  !multiple?
end

#to_html ⇒ Object 



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# File 'lib/formtastic/inputs/select_input.rb', line 140

def to_html
  input_wrapping do
    label_html <<
    (options[:group_by] ? grouped_select_html : select_html)
  end
end