Module: ActionView::Helpers::FormOptionsHelper
- Includes:
- TextHelper
- Included in:
- ActionView::Helpers, Tags::Base
- Defined in:
- actionview/lib/action_view/helpers/form_options_helper.rb
Overview
Provides a number of methods for turning different kinds of containers into a set of option tags.
The collection_select
, select
and time_zone_select
methods take an options
parameter, a hash:
-
:include_blank
- set to true or a prompt string if the first option element of the select element is a blank. Useful if there is not a default value required for the select element.select(“post”, “category”, Post::CATEGORIES, true)
could become:
<select name="post[category]">
<option></option>
<option>joke</option>
<option>poem</option>
</select>
Another common case is a select tag for a belongs_to
-associated object.
Example with @post.person_id => 2:
select("post", "person_id", Person.all.collect {|p| [ p.name, p.id ] }, {include_blank: 'None'})
could become:
<select name="post[person_id]">
<option value="">None</option>
<option value="1">David</option>
<option value="2" selected="selected">Sam</option>
<option value="3">Tobias</option>
</select>
-
:prompt
- set to true or a prompt string. When the select element doesn’t have a value yet, this prepends an option with a generic prompt – “Please select” – or the given prompt string.select(“post”, “person_id”, Person.all.collect {|p| [ p.name, p.id ] }, ‘Select Person’)
could become:
<select name="post[person_id]">
<option value="">Select Person</option>
<option value="1">David</option>
<option value="2">Sam</option>
<option value="3">Tobias</option>
</select>
Like the other form helpers, select
can accept an :index
option to manually set the ID used in the resulting output. Unlike other helpers, select
expects this option to be in the html_options
parameter.
select("album[]", "genre", %w[rap rock country], {}, { index: nil })
becomes:
<select name="album[][genre]" id="album__genre">
<option value="rap">rap</option>
<option value="rock">rock</option>
<option value="country">country</option>
</select>
-
:disabled
- can be a single value or an array of values that will be disabled options in the final output.select(“post”, “category”, Post::CATEGORIES, ‘restricted’)
could become:
<select name="post[category]">
<option></option>
<option>joke</option>
<option>poem</option>
<option disabled="disabled">restricted</option>
</select>
When used with the collection_select
helper, :disabled
can also be a Proc that identifies those options that should be disabled.
collection_select(:post, :category_id, Category.all, :id, :name, {disabled: lambda{|category| category.archived? }})
If the categories “2008 stuff” and “Christmas” return true when the method archived?
is called, this would return:
<select name="post[category_id]">
<option value="1" disabled="disabled">2008 stuff</option>
<option value="2" disabled="disabled">Christmas</option>
<option value="3">Jokes</option>
<option value="4">Poems</option>
</select>
Constant Summary
Constants included from TagHelper
TagHelper::BOOLEAN_ATTRIBUTES, TagHelper::PRE_CONTENT_STRINGS
Instance Method Summary collapse
-
#collection_check_boxes(object, method, collection, value_method, text_method, options = {}, html_options = {}, &block) ⇒ Object
Returns check box tags for the collection of existing return values of
method
forobject
‘s class. -
#collection_radio_buttons(object, method, collection, value_method, text_method, options = {}, html_options = {}, &block) ⇒ Object
Returns radio button tags for the collection of existing return values of
method
forobject
‘s class. -
#collection_select(object, method, collection, value_method, text_method, options = {}, html_options = {}) ⇒ Object
Returns
<select>
and<option>
tags for the collection of existing return values ofmethod
forobject
‘s class. -
#grouped_collection_select(object, method, collection, group_method, group_label_method, option_key_method, option_value_method, options = {}, html_options = {}) ⇒ Object
Returns
<select>
,<optgroup>
and<option>
tags for the collection of existing return values ofmethod
forobject
‘s class. -
#grouped_options_for_select(grouped_options, selected_key = nil, options = {}) ⇒ Object
Returns a string of
<option>
tags, likeoptions_for_select
, but wraps them with<optgroup>
tags. -
#option_groups_from_collection_for_select(collection, group_method, group_label_method, option_key_method, option_value_method, selected_key = nil) ⇒ Object
Returns a string of
<option>
tags, likeoptions_from_collection_for_select
, but groups them by<optgroup>
tags based on the object relationships of the arguments. -
#options_for_select(container, selected = nil) ⇒ Object
Accepts a container (hash, array, enumerable, your type) and returns a string of option tags.
-
#options_from_collection_for_select(collection, value_method, text_method, selected = nil) ⇒ Object
Returns a string of option tags that have been compiled by iterating over the
collection
and assigning the result of a call to thevalue_method
as the option value and thetext_method
as the option text. -
#select(object, method, choices, options = {}, html_options = {}) ⇒ Object
Create a select tag and a series of contained option tags for the provided object and method.
-
#time_zone_options_for_select(selected = nil, priority_zones = nil, model = ::ActiveSupport::TimeZone) ⇒ Object
Returns a string of option tags for pretty much any time zone in the world.
-
#time_zone_select(object, method, priority_zones = nil, options = {}, html_options = {}) ⇒ Object
Return select and option tags for the given object and method, using #time_zone_options_for_select to generate the list of option tags.
Methods included from TextHelper
#concat, #current_cycle, #cycle, #excerpt, #highlight, #pluralize, #reset_cycle, #safe_concat, #simple_format, #truncate, #word_wrap
Methods included from ActiveSupport::Concern
#append_features, extended, #included
Methods included from TagHelper
#cdata_section, #content_tag, #escape_once, #tag
Methods included from CaptureHelper
#capture, #content_for, #content_for?, #flush_output_buffer, #provide, #with_output_buffer
Methods included from SanitizeHelper
#sanitize, #sanitize_css, #strip_links, #strip_tags
Instance Method Details
#collection_check_boxes(object, method, collection, value_method, text_method, options = {}, html_options = {}, &block) ⇒ Object
Returns check box tags for the collection of existing return values of method
for object
‘s class. The value returned from calling method
on the instance object
will be selected. If calling method
returns nil
, no selection is made.
The :value_method
and :text_method
parameters are methods to be called on each member of collection
. The return values are used as the value
attribute and contents of each check box tag, respectively. They can also be any object that responds to call
, such as a proc
, that will be called for each member of the collection
to retrieve the value/text.
Example object structure for use with this method:
class Post < ActiveRecord::Base
has_and_belongs_to_many :authors
end
class Author < ActiveRecord::Base
has_and_belongs_to_many :posts
def name_with_initial
"#{first_name.first}. #{last_name}"
end
end
Sample usage (selecting the associated Author for an instance of Post, @post
):
collection_check_boxes(:post, :author_ids, Author.all, :id, :name_with_initial)
If @post.author_ids
is already [1]
, this would return:
<input id="post_author_ids_1" name="post[author_ids][]" type="checkbox" value="1" checked="checked" />
<label for="post_author_ids_1">D. Heinemeier Hansson</label>
<input id="post_author_ids_2" name="post[author_ids][]" type="checkbox" value="2" />
<label for="post_author_ids_2">D. Thomas</label>
<input id="post_author_ids_3" name="post[author_ids][]" type="checkbox" value="3" />
<label for="post_author_ids_3">M. Clark</label>
<input name="post[author_ids][]" type="hidden" value="" />
It is also possible to customize the way the elements will be shown by giving a block to the method:
collection_check_boxes(:post, :author_ids, Author.all, :id, :name_with_initial) do |b|
b.label { b.check_box }
end
The argument passed to the block is a special kind of builder for this collection, which has the ability to generate the label and check box for the current item in the collection, with proper text and value. Using it, you can change the label and check box display order or even use the label as wrapper, as in the example above.
The builder methods label
and check_box
also accept extra html options:
collection_check_boxes(:post, :author_ids, Author.all, :id, :name_with_initial) do |b|
b.label(class: "check_box") { b.check_box(class: "check_box") }
end
There are also three special methods available: object
, text
and value
, which are the current item being rendered, its text and value methods, respectively. You can use them like this:
collection_check_boxes(:post, :author_ids, Author.all, :id, :name_with_initial) do |b|
b.label(:"data-value" => b.value) { b.check_box + b.text }
end
698 699 700 |
# File 'actionview/lib/action_view/helpers/form_options_helper.rb', line 698 def collection_check_boxes(object, method, collection, value_method, text_method, = {}, = {}, &block) Tags::CollectionCheckBoxes.new(object, method, self, collection, value_method, text_method, , ).render(&block) end |
#collection_radio_buttons(object, method, collection, value_method, text_method, options = {}, html_options = {}, &block) ⇒ Object
Returns radio button tags for the collection of existing return values of method
for object
‘s class. The value returned from calling method
on the instance object
will be selected. If calling method
returns nil
, no selection is made.
The :value_method
and :text_method
parameters are methods to be called on each member of collection
. The return values are used as the value
attribute and contents of each radio button tag, respectively. They can also be any object that responds to call
, such as a proc
, that will be called for each member of the collection
to retrieve the value/text.
Example object structure for use with this method:
class Post < ActiveRecord::Base
belongs_to :author
end
class Author < ActiveRecord::Base
has_many :posts
def name_with_initial
"#{first_name.first}. #{last_name}"
end
end
Sample usage (selecting the associated Author for an instance of Post, @post
):
(:post, :author_id, Author.all, :id, :name_with_initial)
If @post.author_id
is already 1
, this would return:
<input id="post_author_id_1" name="post[author_id]" type="radio" value="1" checked="checked" />
<label for="post_author_id_1">D. Heinemeier Hansson</label>
<input id="post_author_id_2" name="post[author_id]" type="radio" value="2" />
<label for="post_author_id_2">D. Thomas</label>
<input id="post_author_id_3" name="post[author_id]" type="radio" value="3" />
<label for="post_author_id_3">M. Clark</label>
It is also possible to customize the way the elements will be shown by giving a block to the method:
(:post, :author_id, Author.all, :id, :name_with_initial) do |b|
b.label { b. }
end
The argument passed to the block is a special kind of builder for this collection, which has the ability to generate the label and radio button for the current item in the collection, with proper text and value. Using it, you can change the label and radio button display order or even use the label as wrapper, as in the example above.
The builder methods label
and radio_button
also accept extra html options:
(:post, :author_id, Author.all, :id, :name_with_initial) do |b|
b.label(class: "radio_button") { b.(class: "radio_button") }
end
There are also three special methods available: object
, text
and value
, which are the current item being rendered, its text and value methods, respectively. You can use them like this:
(:post, :author_id, Author.all, :id, :name_with_initial) do |b|
b.label(:"data-value" => b.value) { b. + b.text }
end
635 636 637 |
# File 'actionview/lib/action_view/helpers/form_options_helper.rb', line 635 def (object, method, collection, value_method, text_method, = {}, = {}, &block) Tags::CollectionRadioButtons.new(object, method, self, collection, value_method, text_method, , ).render(&block) end |
#collection_select(object, method, collection, value_method, text_method, options = {}, html_options = {}) ⇒ Object
Returns <select>
and <option>
tags for the collection of existing return values of method
for object
‘s class. The value returned from calling method
on the instance object
will be selected. If calling method
returns nil
, no selection is made without including :prompt
or :include_blank
in the options
hash.
The :value_method
and :text_method
parameters are methods to be called on each member of collection
. The return values are used as the value
attribute and contents of each <option>
tag, respectively. They can also be any object that responds to call
, such as a proc
, that will be called for each member of the collection
to retrieve the value/text.
Example object structure for use with this method:
class Post < ActiveRecord::Base
belongs_to :author
end
class Author < ActiveRecord::Base
has_many :posts
def name_with_initial
"#{first_name.first}. #{last_name}"
end
end
Sample usage (selecting the associated Author for an instance of Post, @post
):
collection_select(:post, :author_id, Author.all, :id, :name_with_initial, prompt: true)
If @post.author_id
is already 1
, this would return:
<select name="post[author_id]">
<option value="">Please select</option>
<option value="1" selected="selected">D. Heinemeier Hansson</option>
<option value="2">D. Thomas</option>
<option value="3">M. Clark</option>
</select>
189 190 191 |
# File 'actionview/lib/action_view/helpers/form_options_helper.rb', line 189 def collection_select(object, method, collection, value_method, text_method, = {}, = {}) Tags::CollectionSelect.new(object, method, self, collection, value_method, text_method, , ).render end |
#grouped_collection_select(object, method, collection, group_method, group_label_method, option_key_method, option_value_method, options = {}, html_options = {}) ⇒ Object
Returns <select>
, <optgroup>
and <option>
tags for the collection of existing return values of method
for object
‘s class. The value returned from calling method
on the instance object
will be selected. If calling method
returns nil
, no selection is made without including :prompt
or :include_blank
in the options
hash.
Parameters:
-
object
- The instance of the class to be used for the select tag -
method
- The attribute ofobject
corresponding to the select tag -
collection
- An array of objects representing the<optgroup>
tags. -
group_method
- The name of a method which, when called on a member ofcollection
, returns an array of child objects representing the<option>
tags. -
group_label_method
- The name of a method which, when called on a member ofcollection
, returns a string to be used as thelabel
attribute for its<optgroup>
tag. -
option_key_method
- The name of a method which, when called on a child object of a member ofcollection
, returns a value to be used as thevalue
attribute for its<option>
tag. -
option_value_method
- The name of a method which, when called on a child object of a member ofcollection
, returns a value to be used as the contents of its<option>
tag.
Example object structure for use with this method:
class Continent < ActiveRecord::Base
has_many :countries
# attribs: id, name
end
class Country < ActiveRecord::Base
belongs_to :continent
# attribs: id, name, continent_id
end
class City < ActiveRecord::Base
belongs_to :country
# attribs: id, name, country_id
end
Sample usage:
grouped_collection_select(:city, :country_id, @continents, :countries, :name, :id, :name)
Possible output:
<select name="city[country_id]">
<optgroup label="Africa">
<option value="1">South Africa</option>
<option value="3">Somalia</option>
</optgroup>
<optgroup label="Europe">
<option value="7" selected="selected">Denmark</option>
<option value="2">Ireland</option>
</optgroup>
</select>
245 246 247 |
# File 'actionview/lib/action_view/helpers/form_options_helper.rb', line 245 def grouped_collection_select(object, method, collection, group_method, group_label_method, option_key_method, option_value_method, = {}, = {}) Tags::GroupedCollectionSelect.new(object, method, self, collection, group_method, group_label_method, option_key_method, option_value_method, , ).render end |
#grouped_options_for_select(grouped_options, selected_key = nil, options = {}) ⇒ Object
Returns a string of <option>
tags, like options_for_select
, but wraps them with <optgroup>
tags.
Parameters:
-
grouped_options
- Accepts a nested array or hash of strings. The first value serves as the<optgroup>
label while the second value must be an array of options. The second value can be a nested array of text-value pairs. Seeoptions_for_select
for more info.Ex. ["North America",[["United States","US"],["Canada","CA"]]]
-
selected_key
- A value equal to thevalue
attribute for one of the<option>
tags, which will have theselected
attribute set. Note: It is possible for this value to match multiple options as you might have the same option in multiple groups. Each will then getselected="selected"
.
Options:
-
:prompt
- set to true or a prompt string. When the select element doesn’t have a value yet, this prepends an option with a generic prompt - “Please select” - or the given prompt string. -
:divider
- the divider for the options groups.grouped_options = [
['North America', [['United States','US'],'Canada']], ['Europe', ['Denmark','Germany','France']]
] grouped_options_for_select(grouped_options)
grouped_options =
'North America' => [['United States','US'], 'Canada'], 'Europe' => ['Denmark','Germany','France']
grouped_options_for_select(grouped_options)
Possible output:
<optgroup label="North America">
<option value="US">United States</option>
<option value="Canada">Canada</option>
</optgroup>
<optgroup label="Europe">
<option value="Denmark">Denmark</option>
<option value="Germany">Germany</option>
<option value="France">France</option>
</optgroup>
grouped_options = [
[['United States','US'], 'Canada'],
['Denmark','Germany','France']
]
grouped_options_for_select(grouped_options, nil, divider: '---------')
Possible output:
<optgroup label="---------">
<option value="US">United States</option>
<option value="Canada">Canada</option>
</optgroup>
<optgroup label="---------">
<option value="Denmark">Denmark</option>
<option value="Germany">Germany</option>
<option value="France">France</option>
</optgroup>
Note: Only the <optgroup>
and <option>
tags are returned, so you still have to wrap the output in an appropriate <select>
tag.
512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 |
# File 'actionview/lib/action_view/helpers/form_options_helper.rb', line 512 def (, selected_key = nil, = {}) prompt = [:prompt] divider = [:divider] body = "".html_safe if prompt body.safe_concat content_tag(:option, prompt_text(prompt), value: "") end .each do |container| html_attributes = option_html_attributes(container) if divider label = divider else label, container = container end html_attributes = { label: label }.merge!(html_attributes) body.safe_concat content_tag(:optgroup, (container, selected_key), html_attributes) end body end |
#option_groups_from_collection_for_select(collection, group_method, group_label_method, option_key_method, option_value_method, selected_key = nil) ⇒ Object
Returns a string of <option>
tags, like options_from_collection_for_select
, but groups them by <optgroup>
tags based on the object relationships of the arguments.
Parameters:
-
collection
- An array of objects representing the<optgroup>
tags. -
group_method
- The name of a method which, when called on a member ofcollection
, returns an array of child objects representing the<option>
tags. -
group_label_method+ - The name of a method which, when called on a member of
collection
, returns a string to be used as thelabel
attribute for its<optgroup>
tag. -
option_key_method
- The name of a method which, when called on a child object of a member ofcollection
, returns a value to be used as thevalue
attribute for its<option>
tag. -
option_value_method
- The name of a method which, when called on a child object of a member ofcollection
, returns a value to be used as the contents of its<option>
tag. -
selected_key
- A value equal to thevalue
attribute for one of the<option>
tags, which will have theselected
attribute set. Corresponds to the return value of one of the calls tooption_key_method
. Ifnil
, no selection is made. Can also be a hash if disabled values are to be specified.
Example object structure for use with this method:
class Continent < ActiveRecord::Base
has_many :countries
# attribs: id, name
end
class Country < ActiveRecord::Base
belongs_to :continent
# attribs: id, name, continent_id
end
Sample usage:
option_groups_from_collection_for_select(@continents, :countries, :name, :id, :name, 3)
Possible output:
<optgroup label="Africa">
<option value="1">Egypt</option>
<option value="4">Rwanda</option>
...
</optgroup>
<optgroup label="Asia">
<option value="3" selected="selected">China</option>
<option value="12">India</option>
<option value="5">Japan</option>
...
</optgroup>
Note: Only the <optgroup>
and <option>
tags are returned, so you still have to wrap the output in an appropriate <select>
tag.
442 443 444 445 446 447 448 449 |
# File 'actionview/lib/action_view/helpers/form_options_helper.rb', line 442 def option_groups_from_collection_for_select(collection, group_method, group_label_method, option_key_method, option_value_method, selected_key = nil) collection.map do |group| = ( group.send(group_method), option_key_method, option_value_method, selected_key) content_tag(:optgroup, , label: group.send(group_label_method)) end.join.html_safe end |
#options_for_select(container, selected = nil) ⇒ Object
Accepts a container (hash, array, enumerable, your type) and returns a string of option tags. Given a container where the elements respond to first and last (such as a two-element array), the “lasts” serve as option values and the “firsts” as option text. Hashes are turned into this form automatically, so the keys become “firsts” and values become lasts. If selected
is specified, the matching “last” or element will get the selected option-tag. selected
may also be an array of values to be selected when using a multiple select.
([["Dollar", "$"], ["Kroner", "DKK"]])
# => <option value="$">Dollar</option>
# => <option value="DKK">Kroner</option>
([ "VISA", "MasterCard" ], "MasterCard")
# => <option>VISA</option>
# => <option selected="selected">MasterCard</option>
({ "Basic" => "$20", "Plus" => "$40" }, "$40")
# => <option value="$20">Basic</option>
# => <option value="$40" selected="selected">Plus</option>
([ "VISA", "MasterCard", "Discover" ], ["VISA", "Discover"])
# => <option selected="selected">VISA</option>
# => <option>MasterCard</option>
# => <option selected="selected">Discover</option>
You can optionally provide html attributes as the last element of the array.
([ "Denmark", ["USA", {class: 'bold'}], "Sweden" ], ["USA", "Sweden"])
# => <option value="Denmark">Denmark</option>
# => <option value="USA" class="bold" selected="selected">USA</option>
# => <option value="Sweden" selected="selected">Sweden</option>
([["Dollar", "$", {class: "bold"}], ["Kroner", "DKK", {onclick: "alert('HI');"}]])
# => <option value="$" class="bold">Dollar</option>
# => <option value="DKK" onclick="alert('HI');">Kroner</option>
If you wish to specify disabled option tags, set selected
to be a hash, with :disabled
being either a value or array of values to be disabled. In this case, you can use :selected
to specify selected option tags.
(["Free", "Basic", "Advanced", "Super Platinum"], disabled: "Super Platinum")
# => <option value="Free">Free</option>
# => <option value="Basic">Basic</option>
# => <option value="Advanced">Advanced</option>
# => <option value="Super Platinum" disabled="disabled">Super Platinum</option>
(["Free", "Basic", "Advanced", "Super Platinum"], disabled: ["Advanced", "Super Platinum"])
# => <option value="Free">Free</option>
# => <option value="Basic">Basic</option>
# => <option value="Advanced" disabled="disabled">Advanced</option>
# => <option value="Super Platinum" disabled="disabled">Super Platinum</option>
(["Free", "Basic", "Advanced", "Super Platinum"], selected: "Free", disabled: "Super Platinum")
# => <option value="Free" selected="selected">Free</option>
# => <option value="Basic">Basic</option>
# => <option value="Advanced">Advanced</option>
# => <option value="Super Platinum" disabled="disabled">Super Platinum</option>
NOTE: Only the option tags are returned, you have to wrap this call in a regular HTML select tag.
338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 |
# File 'actionview/lib/action_view/helpers/form_options_helper.rb', line 338 def (container, selected = nil) return container if String === container selected, disabled = extract_selected_and_disabled(selected).map do |r| Array(r).map { |item| item.to_s } end container.map do |element| html_attributes = option_html_attributes(element) text, value = option_text_and_value(element).map { |item| item.to_s } html_attributes[:selected] = option_value_selected?(value, selected) html_attributes[:disabled] = disabled && option_value_selected?(value, disabled) html_attributes[:value] = value content_tag_string(:option, text, html_attributes) end.join("\n").html_safe end |
#options_from_collection_for_select(collection, value_method, text_method, selected = nil) ⇒ Object
Returns a string of option tags that have been compiled by iterating over the collection
and assigning the result of a call to the value_method
as the option value and the text_method
as the option text.
(@people, 'id', 'name')
# => <option value="#{person.id}">#{person.name}</option>
This is more often than not used inside a #select_tag like this example:
select_tag 'person', (@people, 'id', 'name')
If selected
is specified as a value or array of values, the element(s) returning a match on value_method
will be selected option tag(s).
If selected
is specified as a Proc, those members of the collection that return true for the anonymous function are the selected values.
selected
can also be a hash, specifying both :selected
and/or :disabled
values as required.
Be sure to specify the same class as the value_method
when specifying selected or disabled options. Failure to do this will produce undesired results. Example:
(@people, 'id', 'name', '1')
Will not select a person with the id of 1 because 1 (an Integer) is not the same as ‘1’ (a string)
(@people, 'id', 'name', 1)
should produce the desired results.
381 382 383 384 385 386 387 388 389 390 391 392 |
# File 'actionview/lib/action_view/helpers/form_options_helper.rb', line 381 def (collection, value_method, text_method, selected = nil) = collection.map do |element| [value_for_collection(element, text_method), value_for_collection(element, value_method), option_html_attributes(element)] end selected, disabled = extract_selected_and_disabled(selected) select_deselect = { selected: extract_values_from_collection(collection, value_method, selected), disabled: extract_values_from_collection(collection, value_method, disabled) } (, select_deselect) end |
#select(object, method, choices, options = {}, html_options = {}) ⇒ Object
Create a select tag and a series of contained option tags for the provided object and method. The option currently held by the object will be selected, provided that the object is available.
There are two possible formats for the choices parameter, corresponding to other helpers’ output:
* A flat collection: see options_for_select
* A nested collection: see grouped_options_for_select
Example with @post.person_id => 1:
select("post", "person_id", Person.all.collect {|p| [ p.name, p.id ] }, { include_blank: true })
could become:
<select name="post[person_id]">
<option value=""></option>
<option value="1" selected="selected">David</option>
<option value="2">Sam</option>
<option value="3">Tobias</option>
</select>
This can be used to provide a default set of options in the standard way: before rendering the create form, a new model instance is assigned the default options and bound to @model_name. Usually this model is not saved to the database. Instead, a second model object is created when the create request is received. This allows the user to submit a form page more than once with the expected results of creating multiple records. In addition, this allows a single partial to be used to generate form inputs for both edit and create forms.
By default, post.person_id
is the selected option. Specify selected: value
to use a different selection or selected: nil
to leave all options unselected. Similarly, you can specify values to be disabled in the option tags by specifying the :disabled
option. This can either be a single value or an array of values to be disabled.
Gotcha
The HTML specification says when multiple
parameter passed to select and all options got deselected web browsers do not send any value to server. Unfortunately this introduces a gotcha: if an User
model has many roles
and have role_ids
accessor, and in the form that edits roles of the user the user deselects all roles from role_ids
multiple select box, no role_ids
parameter is sent. So, any mass-assignment idiom like
@user.update(params[:user])
wouldn’t update roles.
To prevent this the helper generates an auxiliary hidden field before every multiple select. The hidden field has the same name as multiple select and blank value.
This way, the client either sends only the hidden field (representing the deselected multiple select box), or both fields. Since the HTML specification says key/value pairs have to be sent in the same order they appear in the form, and parameters extraction gets the last occurrence of any repeated key in the query string, that works for ordinary forms.
In case if you don’t want the helper to generate this hidden field you can specify include_hidden: false
option.
150 151 152 |
# File 'actionview/lib/action_view/helpers/form_options_helper.rb', line 150 def select(object, method, choices, = {}, = {}) Tags::Select.new(object, method, self, choices, , ).render end |
#time_zone_options_for_select(selected = nil, priority_zones = nil, model = ::ActiveSupport::TimeZone) ⇒ Object
Returns a string of option tags for pretty much any time zone in the world. Supply a ActiveSupport::TimeZone name as selected
to have it marked as the selected option tag. You can also supply an array of ActiveSupport::TimeZone objects as priority_zones
, so that they will be listed above the rest of the (long) list. (You can use ActiveSupport::TimeZone.us_zones as a convenience for obtaining a list of the US time zones, or a Regexp to select the zones of your choice)
The selected
parameter must be either nil
, or a string that names a ActiveSupport::TimeZone.
By default, model
is the ActiveSupport::TimeZone constant (which can be obtained in Active Record as a value object). The only requirement is that the model
parameter be an object that responds to all
, and returns an array of objects that represent time zones.
NOTE: Only the option tags are returned, you have to wrap this call in a regular HTML select tag.
556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 |
# File 'actionview/lib/action_view/helpers/form_options_helper.rb', line 556 def (selected = nil, priority_zones = nil, model = ::ActiveSupport::TimeZone) = "".html_safe zones = model.all convert_zones = lambda { |list| list.map { |z| [ z.to_s, z.name ] } } if priority_zones if priority_zones.is_a?(Regexp) priority_zones = zones.select { |z| z =~ priority_zones } end .safe_concat (convert_zones[priority_zones], selected) .safe_concat content_tag(:option, '-------------', value: '', disabled: true) .safe_concat "\n" zones = zones - priority_zones end .safe_concat (convert_zones[zones], selected) end |
#time_zone_select(object, method, priority_zones = nil, options = {}, html_options = {}) ⇒ Object
Return select and option tags for the given object and method, using #time_zone_options_for_select to generate the list of option tags.
In addition to the :include_blank
option documented above, this method also supports a :model
option, which defaults to ActiveSupport::TimeZone. This may be used by users to specify a different time zone model object. (See time_zone_options_for_select
for more information.)
You can also supply an array of ActiveSupport::TimeZone objects as priority_zones
, so that they will be listed above the rest of the (long) list. (You can use ActiveSupport::TimeZone.us_zones as a convenience for obtaining a list of the US time zones, or a Regexp to select the zones of your choice)
Finally, this method supports a :default
option, which selects a default ActiveSupport::TimeZone if the object’s time zone is nil
.
time_zone_select( "user", "time_zone", nil, include_blank: true)
time_zone_select( "user", "time_zone", nil, default: "Pacific Time (US & Canada)" )
time_zone_select( "user", 'time_zone', ActiveSupport::TimeZone.us_zones, default: "Pacific Time (US & Canada)")
time_zone_select( "user", 'time_zone', [ ActiveSupport::TimeZone['Alaska'], ActiveSupport::TimeZone['Hawaii'] ])
time_zone_select( "user", 'time_zone', /Australia/)
time_zone_select( "user", "time_zone", ActiveSupport::TimeZone.all.sort, model: ActiveSupport::TimeZone)
278 279 280 |
# File 'actionview/lib/action_view/helpers/form_options_helper.rb', line 278 def time_zone_select(object, method, priority_zones = nil, = {}, = {}) Tags::TimeZoneSelect.new(object, method, self, priority_zones, , ).render end |