# SimpleForm - Rails forms made easy.
[](http://travis-ci.org/plataformatec/simple_form)
**SimpleForm** aims to be as flexible as possible while helping you with powerful components to create
your forms. The basic goal of simple form is to not touch your way of defining the layout, letting
you find the better design for your eyes. Good part of the DSL was inherited from Formtastic,
which we are thankful for and should make you feel right at home.
## Installation
Install the gem:
`gem install simple_form`
Add it to your Gemfile:
`gem "simple_form"`
Run the generator:
`rails generate simple_form:install`
Also, if you want to use the country select, you will need the *country_select* plugin, install
with following command:
`rails plugin install git://github.com/rails/country_select.git`
And you are ready to go. Since this branch aims Rails 3 support, if you want to use it with
Rails 2.3 you should check this branch:
`http://github.com/plataformatec/simple_form/tree/v1.0`
## Configuration
**SimpleForm** has several configuration values. You can read and change them in the initializer
created by **SimpleForm**, so if you haven't executed the command below yet, please do:
`rails generate simple_form:install`
### Twitter Bootstrap
**SimpleForm** 2.0 can be easily integrate to the [Twitter Bootstrap](http://twitter.github.com/bootstrap)
to do that you have to use the `bootstrap` options in the install generator, like this:
`rails generate simple_form:install --bootstrap`
You have to be sure that you added a copy of the [Twitter Bootstrap](http://twitter.github.com/bootstrap)
assets on your application.
For more informations see the output of the generator and our
[example application](https://github.com/rafaelfranca/simple_form-bootstrap) code.
You can see how it works using [this link](http://simple-form-bootstrap.herokuapp.com/).
### The wrappers API
With **SimpleForm** you can configure how your components will be renderized using the wrappers API.
The syntax looks like this:
```ruby
config.wrappers :tag => :div, :class => :input,
:error_class => :field_with_errors do |b|
# Form extensions
b.use :html5
b.optional :pattern
b.use :maxlength
b.use :placeholder
b.use :readonly
# Form components
b.use :label_input
b.use :hint, :tag => :span, :class => :hint
b.use :error, :tag => :span, :class => :error
end
```
The _Form components_ will generate the form tags like labels, inputs, hints or errors contents.
The _Form extensions_ are used to generate some attributes or perform some lookups on the model to
add extra informations to your components.
You can create new _Form components_ using the wrappers API as in the following example:
```ruby
config.wrappers do |b|
b.use :placeholder
b.use :label_input
b.use :tag => :div, :class => 'separator' do |component|
component.use :hint, :tag => :span, :class => :hint
component.use :error, :tag => :span, :class => :error
end
end
```
this will wrap the hint and error components with one tag `div` using the class `'separator'`.
If you want to customize the custon _Form components_ on demand you can give it a name like this:
```ruby
config.wrappers do |b|
b.use :placeholder
b.use :label_input
b.use :my_wrapper, :tag => :div, :class => 'separator' do |component|
component.use :hint, :tag => :span, :class => :hint
component.use :error, :tag => :span, :class => :error
end
end
```
and now you can pass options to your `input` calls to customize the `:my_wrapper` _Form component_.
```ruby
# Completely turns off the custom wrapper
f.input :name, :my_wrapper => false
# Configure the html
f.input :name, :my_wrapper_html => { :id => 'special_id' }
# Configure the tag
f.input :name, :my_wrapper_tag => :p
```
You can also define more the one wrapper and pick one to render in a specific form or input.
To define another wrapper you have to give it a name, as the follow:
```ruby
config.wrappers :small do |b|
b.use :placeholder
b.use :label_input
end
```
and use it in this way
```ruby
# Specifying to whole form
simple_form_for @user, :wrapper => :small do |f|
f.input :name
end
# Specifying to one input
simple_form_for @user do |f|
f.input :name, :wrapper => :small
end
```
**SimpleForm** also allows you to use optional elements. For instance, let's suppose you want to use
hints or placeholders, but you don't want them to be generated automatically. You can set their
default values to `false` or use the `optional` method:
```ruby
config.wrappers :placeholder => false do |b|
b.use :placeholder
b.use :label_input
b.use :tag => :div, :class => 'separator' do |component|
component.optional :hint, :tag => :span, :class => :hint
component.use :error, :tag => :span, :class => :error
end
end
```
By setting it to `false`, a placeholder will only be generated when `:placeholder => true` is
explicitly used. The same for hint.
## Usage
**SimpleForm** was designed to be customized as you need to. Basically it's a stack of components that
are invoked to create a complete html input for you, which by default contains label, hints, errors
and the input itself. It does not aim to create a lot of different logic from the default Rails
form helpers, as they do a great work by themselves. Instead, **SimpleForm** acts as a DSL and just
maps your input type (retrieved from the column definition in the database) to an specific helper method.
To start using **SimpleForm** you just have to use the helper it provides:
```erb
<%= simple_form_for @user do |f| %>
<%= f.input :username %>
<%= f.input :password %>
<%= f.button :submit %>
<% end %>
```
This will generate an entire form with labels for user name and password as well, and render errors
by default when you render the form with invalid data (after submitting for example).
You can overwrite the default label by passing it to the input method. You can also add a hint or
even a placeholder:
```erb
<%= simple_form_for @user do |f| %>
<%= f.input :username, :label => 'Your username please' %>
<%= f.input :password, :hint => 'No special characters.' %>
<%= f.input :email, :placeholder => 'user@domain.com' %>
<%= f.button :submit %>
<% end %>
```
In some cases you may want to disable labels, hints or error. Or you may wan to configure the html
of any of them:
```erb
<%= simple_form_for @user do |f| %>
<%= f.input :username, :label_html => { :class => 'my_class' } %>
<%= f.input :password, :hint => false, :error_html => { :id => 'password_error'} %>
<%= f.input :password_confirmation, :label => false %>
<%= f.button :submit %>
<% end %>
```
It is also possible to pass any html attribute straight to the input, by using the `:input_html`
option, for instance:
```erb
<%= simple_form_for @user do |f| %>
<%= f.input :username, :input_html => { :class => 'special' } %>
<%= f.input :password, :input_html => { :maxlength => 20 } %>
<%= f.input :remember_me, :input_html => { :value => '1' } %>
<%= f.button :submit %>
<% end %>
```
If you want to pass the same options to all inputs in the form (for example, a default class),
you can use the `:defaults` option in `simple_form_for`. Specific options in `input` call will
overwrite the defaults:
```erb
<%= simple_form_for @user, :defaults => { :input_html => { :class => 'default_class' } } do |f| %>
<%= f.input :username, :input_html => { :class => 'special' } %>
<%= f.input :password, :input_html => { :maxlength => 20 } %>
<%= f.input :remember_me, :input_html => { :value => '1' } %>
<%= f.button :submit %>
<% end %>
```
Since **SimpleForm** generates a wrapper div around your label and input by default, you can pass
any html attribute to that wrapper as well using the `:wrapper_html` option, like so:
```erb
<%= simple_form_for @user do |f| %>
<%= f.input :username, :wrapper_html => { :class => 'username' } %>
<%= f.input :password, :wrapper_html => { :id => 'password' } %>
<%= f.input :remember_me, :wrapper_html => { :class => 'options' } %>
<%= f.button :submit %>
<% end %>
```
By default all inputs are required, which means an * is prepended to the label, but you can disable
it in any input you want:
```erb
<%= simple_form_for @user do |f| %>
<%= f.input :name, :required => false %>
<%= f.input :username %>
<%= f.input :password %>
<%= f.button :submit %>
<% end %>
```
**SimpleForm** also lets you overwrite the default input type it creates:
```erb
<%= simple_form_for @user do |f| %>
<%= f.input :username %>
<%= f.input :password %>
<%= f.input :description, :as => :text %>
<%= f.input :accepts, :as => :radio_buttons %>
<%= f.button :submit %>
<% end %>
```
So instead of a checkbox for the *accepts* attribute, you'll have a pair of radio buttons with yes/no
labels and a text area instead of a text field for the description. You can also render boolean
attributes using `:as => :select` to show a dropdown.
It is also possible to give the `:disabled` option to **SimpleForm**, and it'll automatically mark
the wrapper as disabled with a css class, so you can style labels, hints and other components inside
the wrapper as well:
```erb
<%= simple_form_for @user do |f| %>
<%= f.input :username, :disabled => true, :hint => 'You cannot change your username.' %>
<%= f.button :submit %>
<% end %>
```
**SimpleForm** accepts same options as their corresponding input type helper in Rails:
```erb
<%= simple_form_for @user do |f| %>
<%= f.input :date_of_birth, :as => :date, :start_year => Date.today.year - 90,
:end_year => Date.today.year - 12, :discard_day => true,
:order => [:month, :year] %>
<%= f.button :submit %>
<% end %>
```
**SimpleForm** also allows you to use label, hint, input_field, error and full_error helpers
(please take a look at the rdocs for each method for more info):
```erb
<%= simple_form_for @user do |f| %>
<%= f.label :username %>
<%= f.input_field :username %>
<%= f.hint 'No special characters, please!' %>
<%= f.error :username, :id => 'user_name_error' %>
<%= f.full_error :token %>
<%= f.submit 'Save' %>
<% end %>
```
Any extra option passed to these methods will be rendered as html option.
### Collections
And what if you want to create a select containing the age from 18 to 60 in your form? You can do it
overriding the `:collection` option:
```erb
<%= simple_form_for @user do |f| %>
<%= f.input :user %>
<%= f.input :age, :collection => 18..60 %>
<%= f.button :submit %>
<% end %>
```
Collections can be arrays or ranges, and when a `:collection` is given the `:select` input will be
rendered by default, so we don't need to pass the `:as => :select` option. Other types of collection
are `:radio_buttons` and `:check_boxes`. Those are added by **SimpleForm** to Rails set of form
helpers (read Extra Helpers session below for more information).
Collection inputs accept two other options beside collections:
* _label_method_ => the label method to be applied to the collection to retrieve the label (use this
instead of the `text_method` option in `collection_select`)
* _value_method_ => the value method to be applied to the collection to retrieve the value
Those methods are useful to manipulate the given collection. Both of these options also accept
lambda/procs in case you want to calculate the value or label in a special way eg. custom
translation. All other options given are sent straight to the underlying helper. For example, you
can give prompt as:
```ruby
f.input :age, :collection => 18..60, :prompt => "Select your age"
```
It is also possible to create grouped collection selects, that will use the html *optgroup* tags, like this:
```ruby
f.input :country_id, :collection => @continents, :as => :grouped_select, :group_method => :countries
```
Grouped collection inputs accept the same `:label_method` and `:value_method` options, which will be
used to retrieve label/value attributes for the `option` tags. Besides that, you can give:
* _group_method_ => the method to be called on the given collection to generate the options for
each group (required)
* _group_label_method_ => the label method to be applied on the given collection to retrieve the label
for the _optgroup_ (**SimpleForm** will attempt to guess the best one the same way it does with
`:label_method`)
### Priority
**SimpleForm** also supports `:time_zone` and `:country`. When using such helpers, you can give
`:priority` as option to select which time zones and/or countries should be given higher priority:
```ruby
f.input :residence_country, :priority => [ "Brazil" ]
f.input :time_zone, :priority => /US/
```
Those values can also be configured with a default value to be used site use through the
`SimpleForm.country_priority` and `SimpleForm.time_zone_priority` helpers.
Note: While using `country_select` if you want to restrict to only a subset of countries for a specific
drop down then you may use the `:collection` option:
```ruby
f.input :shipping_country, :priority => [ "Brazil" ], :collection => [ "Australia", "Brazil", "New Zealand"]
```
### Wrapper
**SimpleForm** allows you to add a wrapper which contains the label, error, hint and input.
The first step is to configure a wrapper tag:
```ruby
SimpleForm.wrapper_tag = :p
```
And now, you don't need to wrap your `f.input` calls anymore:
```erb
<%= simple_form_for @user do |f| %>
<%= f.input :username %>
<%= f.input :password %>
<%= f.button :submit %>
<% end %>
```
## Associations
To deal with associations, **SimpleForm** can generate select inputs, a series of radios buttons or check boxes.
Lets see how it works: imagine you have a user model that belongs to a company and has_and_belongs_to_many
roles. The structure would be something like:
```ruby
class User < ActiveRecord::Base
belongs_to :company
has_and_belongs_to_many :roles
end
class Company < ActiveRecord::Base
has_many :users
end
class Role < ActiveRecord::Base
has_and_belongs_to_many :users
end
```
Now we have the user form:
```erb
<%= simple_form_for @user do |f| %>
<%= f.input :name %>
<%= f.association :company %>
<%= f.association :roles %>
<%= f.button :submit %>
<% end %>
```
Simple enough right? This is going to render a `:select` input for choosing the `:company`, and another
`:select` input with `:multiple` option for the `:roles`. You can of course change it, to use radios
buttons and check boxes as well:
```ruby
f.association :company, :as => :radio_buttons
f.association :roles, :as => :check_boxes
```
The association helper just invokes input under the hood, so all options available to `:select`,
`:radio_buttons` and `:check_boxes` are also available to association. Additionally, you can specify
the collection by hand, all together with the prompt:
```ruby
f.association :company, :collection => Company.active.all(:order => 'name'), :prompt => "Choose a Company"
```
## Buttons
All web forms need buttons, right? **SimpleForm** wraps them in the DSL, acting like a proxy:
```erb
<%= simple_form_for @user do |f| %>
<%= f.input :name %>
<%= f.button :submit %>
<% end %>
```
The above will simply call submit. You choose to use it or not, it's just a question of taste.
## Wrapping Rails Form Helpers
Say you wanted to use a rails form helper but still wrap it in **SimpleForm** goodness? You can, by
calling input with a block like so:
```erb
<%= f.input :role do %>
<%= f.select :role, Role.all.map { |r| [r.name, r.id, { :class => r.company.id }] }, :include_blank => true %>
<% end %>
```
In the above example, we're taking advantage of Rails 3's select method that allows us to pass in a
hash of additional attributes for each option.
## Extra helpers
**SimpleForm** also comes with some extra helpers you can use inside rails default forms without relying
on `simple_form_for` helper. They are listed below.
### Simple Fields For
Wrapper to use simple form inside a default rails form
```ruby
form_for @user do |f|
f.simple_fields_for :posts do |posts_form|
# Here you have all simple_form methods available
posts_form.input :title
end
end
```
### Collection Radio Buttons
Creates a collection of radio inputs with labels associated (same API as `collection_select`):
```ruby
form_for @user do |f|
f.collection_radio_buttons :options, [[true, 'Yes'] ,[false, 'No']], :first, :last
end
```
```html
```
### Collection Check Box
Creates a collection of check boxes with labels associated (same API as `collection_select`):
```ruby
form_for @user do |f|
f.collection_check_boxes :options, [[true, 'Yes'] ,[false, 'No']], :first, :last
end
```
```html
```
To use this with associations in your model, you can do the following:
```ruby
form_for @user do |f|
f.collection_check_boxes :role_ids, Role.all, :id, :name # using :roles here is not going to work.
end
```
## Mappings/Inputs available
**SimpleForm** comes with a lot of default mappings:
```
Mapping Input Column Type
boolean check box boolean
string text field string
email email field string with name matching "email"
url url field string with name matching "url"
tel tel field string with name matching "phone"
password password field string with name matching "password"
search search -
text text area text
file file field string, responding to file methods
hidden hidden field -
integer number field integer
float number field float
decimal number field decimal
range range field -
datetime datetime select datetime/timestamp
date date select date
time time select time
select collection select belongs_to/has_many/has_and_belongs_to_many associations
radio_buttons collection radio buttons belongs_to
check_boxes collection check boxes has_many/has_and_belongs_to_many associations
country country select string with name matching "country"
time_zone time zone select string with name matching "time_zone"
```
## Custom inputs
It is very easy to add custom inputs to **SimpleForm**. For instance, if you want to add a custom input
that extends the string one, you just need to add this file:
```ruby
# app/inputs/currency_input.rb
class CurrencyInput < SimpleForm::Inputs::Base
def input
"$ #{@builder.text_field(attribute_name, input_html_options)}".html_safe
end
end
```
And use it in your views:
```ruby
f.input :money, :as => :currency
```
You can also redefine existing **SimpleForm** inputs by creating a new class with the same name. For
instance, if you want to wrap date/time/datetime in a div, you can do:
```ruby
# app/inputs/date_time_input.rb
class DateTimeInput < SimpleForm::Inputs::DateTimeInput
def input
"
#{super}
".html_safe
end
end
```
## Custom form builder
You can create a custom form builder that uses **SimpleForm**.
Create a helper method that calls `simple_form_for` with a custom builder:
```ruby
def custom_form_for(object, *args, &block)
options = args.extract_options!
simple_form_for(object, *(args << options.merge(:builder => CustomFormBuilder)), &block)
end
```
Create a form builder class that inherits from `SimpleForm::FormBuilder`.
```ruby
class CustomFormBuilder < SimpleForm::FormBuilder
def input(attribute_name, options = {}, &block)
options[:input_html].merge! :class => 'custom'
super
end
end
```
## I18n
**SimpleForm** uses all power of I18n API to lookup labels, hints and placeholders. To customize your
forms you can create a locale file like this:
```yaml
en:
simple_form:
labels:
user:
username: 'User name'
password: 'Password'
hints:
user:
username: 'User name to sign in.'
password: 'No special characters, please.'
placeholders:
user:
username: 'Your username'
password: '****'
```
And your forms will use this information to render the components for you.
**SimpleForm** also lets you be more specific, separating lookups through actions for labels, hints and
placeholders. Let's say you want a different label for new and edit actions, the locale file would
be something like:
```yaml
en:
simple_form:
labels:
user:
username: 'User name'
password: 'Password'
edit:
username: 'Change user name'
password: 'Change password'
```
This way **SimpleForm** will figure out the right translation for you, based on the action being
rendered. And to be a little bit DRYer with your locale file, you can specify defaults for all
models under the 'defaults' key:
```yaml
en:
simple_form:
labels:
defaults:
username: 'User name'
password: 'Password'
new:
username: 'Choose a user name'
hints:
defaults:
username: 'User name to sign in.'
password: 'No special characters, please.'
placeholders:
defaults:
username: 'Your username'
password: '****'
```
**SimpleForm** will always look for a default attribute translation under the "defaults" key if no
specific is found inside the model key.Note that this syntax is different from 1.x. To migrate to
the new syntax, just move "labels.#{attribute}" to "labels.defaults.#{attribute}".
In addition, **SimpleForm** will fallback to default human_attribute_name from Rails when no other
translation is found for labels. Finally, you can also overwrite any label, hint or placeholder
inside your view, just by passing the option manually. This way the I18n lookup will be skipped.
**SimpleForm** also has support for translating options in collection helpers. For instance, given a
User with a `:gender` attribute, you might want to create a select box showing translated labels
that would post either `male` or `female` as value. With **SimpleForm** you could create an input
like this:
```ruby
f.input :gender, :collection => [:male, :female]
```
And **SimpleForm** will try a lookup like this in your locale file, to find the right labels to show:
```yaml
en:
simple_form:
options:
user:
gender:
male: 'Male'
female: "Female'
```
You can also use the `defaults` key as you would do with labels, hints and placeholders. It is
important to notice that **SimpleForm** will only do the lookup for options if you give a collection
composed of symbols only. This is to avoid constant lookups to I18n.
It's also possible to translate buttons, using Rails' built-in I18n support:
```yaml
en:
helpers:
submit:
user:
create: "Add %{model}"
update: "Save Changes"
```
There are other options that can be configured through I18n API, such as required text and boolean.
Be sure to check our locale file or the one copied to your application after you run
`rails generate simple_form:install`.
## HTML 5 Notice
By default, **SimpleForm** will generate input field types and attributes that are supported in HTML5,
but are considered invalid HTML for older document types such as HTML4 or XHTML1.0. The HTML5
extensions include the new field types such as email, number, search, url, tel, and the new
attributes such as required, autofocus, maxlength, min, max, step.
Most browsers will not care, but some of the newer ones - in particular Chrome 10+ - use the
required attribute to force a value into an input and will prevent form submission without it.
Depending on the design of the application this may or may not be desired. In many cases it can
break existing UI's.
It is possible to disable all HTML 5 extensions in **SimpleForm** with the following configuration:
```ruby
SimpleForm.html5 = false # default is true
```
If you want to have all other HTML 5 features, such as the new field types, you can disable only
the browser validation:
```ruby
SimpleForm.browser_validations = false # default is true
```
This option adds a new `novalidate` property to the form, instructing it to skip all HTML 5
validation. The inputs will still be generated with the required and other attributes, that might
help you to use some generic javascript validation.
You can also add `novalidate` to a specific form by setting the option on the form itself:
```erb
<%= simple_form_for(resource, :html => {:novalidate => true}) do |form| %>
```
Please notice that any of the configurations above will disable the `placeholder` component,
which is an HTML 5 feature. We believe most of the newest browsers are handling this attribute fine,
and if they aren't, any plugin you use would take of using the placeholder attribute to do it.
However, you can disable it if you want, by removing the placeholder component from the components
list in **SimpleForm** configuration file.
## Information
### Google Group
If you have any questions, comments, or concerns please use the Google Group instead of the GitHub
Issues tracker:
http://groups.google.com/group/plataformatec-simpleform
### RDocs
You can view the **SimpleForm** documentation in RDoc format here:
http://rubydoc.info/github/plataformatec/simple_form/master/frames
If you need to use **SimpleForm** with Rails 2.3, you can always run `gem server` from the command line
after you install the gem to access the old documentation.
### Bug reports
If you discover any bugs, feel free to create an issue on GitHub. Please add as much information as
possible to help us fixing the possible bug. We also encourage you to help even more by forking and
sending us a pull request.
https://github.com/plataformatec/simple_form/issues
## Maintainers
* José Valim (https://github.com/josevalim)
* Carlos Antonio da Silva (https://github.com/carlosantoniodasilva)
* Rafael Mendonça França (https://github.com/rafaelfranca)
## License
MIT License. Copyright 2012 Plataforma Tecnologia. http://blog.plataformatec.com.br