By [Plataformatec](http://plataformatec.com.br/).
Rails forms made easy.
**Simple Form** 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. Most of the DSL was inherited from Formtastic,
which we are thankful for and should make you feel right at home.
INFO: This README is [also available in a friendly navigable format](http://simple-form.plataformatec.com.br/)
and refers to **Simple Form** 3.1. For older releases, check the related branch for your version.
## Installation
Add it to your Gemfile:
```ruby
gem 'simple_form'
```
Run the following command to install it:
```console
bundle install
```
Run the generator:
```console
rails generate simple_form:install
```
Also, if you want to use the country select, you will need the
[country_select gem](https://rubygems.org/gems/country_select), add it to your Gemfile:
```ruby
gem 'country_select'
```
### Bootstrap
**Simple Form** can be easily integrated to the [Bootstrap](http://getbootstrap.com/).
To do that you have to use the `bootstrap` option in the install generator, like this:
```console
rails generate simple_form:install --bootstrap
```
You have to be sure that you added a copy of the [Bootstrap](http://getbootstrap.com/)
assets on your application.
For more information see the generator output, our
[example application code](https://github.com/rafaelfranca/simple_form-bootstrap) and
[the live example app](http://simple-form-bootstrap.plataformatec.com.br/).
### Zurb Foundation 5
To generate wrappers that are compatible with [Zurb Foundation 5](http://foundation.zurb.com/), pass
the `foundation` option to the generator, like this:
```console
rails generate simple_form:install --foundation
```
Please note that the Foundation wrapper does not support the `:hint` option by default. In order to
enable hints, please uncomment the appropriate line in `config/initializers/simple_form_foundation.rb`.
You will need to provide your own CSS styles for hints.
Please see the [instructions on how to install Foundation in a Rails app](http://foundation.zurb.com/docs/applications.html).
## Usage
**Simple Form** 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 job by themselves. Instead, **Simple Form** acts as a DSL and just
maps your input type (retrieved from the column definition in the database) to a specific helper method.
To start using **Simple Form** 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. For boolean inputs, you can add an inline label as well:
```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.input :remember_me, inline_label: 'Yes, remember me' %>
<%= f.button :submit %>
<% end %>
```
In some cases you may want to disable labels, hints or error. Or you may want 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 **Simple Form** 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 %>
```
Required fields are marked with an * prepended to their labels.
By default all inputs are required. When the form object has `presence` validations attached to its
fields, **Simple Form** tells required and optional fields apart. For performance reasons, this
detection is skipped on validations that make use of conditional options, such as `:if` and `:unless`.
And of course, the `required` property of any input can be overwritten as needed:
```erb
<%= simple_form_for @user do |f| %>
<%= f.input :name, required: false %>
<%= f.input :username %>
<%= f.input :password %>
<%= f.button :submit %>
<% end %>
```
By default, **Simple Form** will look at the column type in the database and use an
appropriate input for the column. For example, a column created with type
`:text` in the database will use a `textarea` input by default. See the section
[Available input types and defaults for each column
type](https://github.com/plataformatec/simple_form#available-input-types-and-defaults-for-each-column-type)
for a complete list of defaults.
**Simple Form** 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 textarea 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 **Simple Form**, 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 %>
```
**Simple Form** 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.input :accepts, as: :boolean, checked_value: true, unchecked_value: false %>
<%= f.button :submit %>
<% end %>
```
**Simple Form** 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.
### Stripping away all wrapper divs
**Simple Form** also allows you to strip away all the div wrappers around the `` field that is
generated with the usual `f.input`.
The easiest way to achieve this is to use `f.input_field`.
Example:
```ruby
simple_form_for @user do |f|
f.input_field :name
f.input_field :remember_me, as: :boolean
end
```
```html
```
For check boxes and radio buttons you can remove the label changing `boolean_style` from default value `:nested` to `:inline`.
Also, `item_wrapper_tag` will not work when `boolean_style` is set to `:nested`.
Example:
```ruby
simple_form_for @user do |f|
f.input_field :name
f.input_field :remember_me, as: :boolean, boolean_style: :inline
end
```
```html
```
Produces:
```html
```
To view the actual RDocs for this, check them out here - http://rubydoc.info/github/plataformatec/simple_form/master/SimpleForm/FormBuilder:input_field
### 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 **Simple Form** to Rails set of form
helpers (read Extra Helpers section 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_ (**Simple Form** will attempt to guess the best one the same way it does with
`:label_method`)
### Priority
**Simple Form** also supports `:time_zone` and `:country`. When using such helpers, you can give
`:priority` as an 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 on the site 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"]
```
### Associations
To deal with associations, **Simple Form** can generate select inputs, a series of radios buttons or checkboxes.
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 radio
buttons and checkboxes 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"
```
In case you want to declare different labels and values:
```ruby
f.association :company, label_method: :company_name, value_method: :id, include_blank: false
```
Please note that the association helper is currently only tested with Active Record. It currently
does not work well with Mongoid and depending on the ORM you're using your mileage may vary.
### Buttons
All web forms need buttons, right? **Simple Form** 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.
The button method also accepts optional parameters, that are delegated to the underlying submit call:
```erb
<%= f.button :submit, "Custom Button Text", class: "my-button" %>
```
### Wrapping Rails Form Helpers
Say you wanted to use a rails form helper but still wrap it in **Simple Form** 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
**Simple Form** 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. It works in the same way that the `fields_for`
Rails helper, but change the builder to use the `SimpleForm::FormBuilder`.
```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 Boxes
Creates a collection of checkboxes 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
```
## Available input types and defaults for each column type
The following table shows the html element you will get for each attribute
according to its database definition. These defaults can be changed by
specifying the helper method in the column `Mapping` as the `as:` option.
Mapping | Generated HTML Element | Database Column Type
--------------- |:-------------------------------------|:--------------------
`boolean` | `input[type=checkbox]` | `boolean`
`string` | `input[type=text]` | `string`
`email` | `input[type=email]` | `string` with `name =~ /email/`
`url` | `input[type=url]` | `string` with `name =~ /url/`
`tel` | `input[type=tel]` | `string` with `name =~ /phone/`
`password` | `input[type=password]` | `string` with `name =~ /password/`
`search` | `input[type=search]` | -
`uuid` | `input[type=text]` | `uuid`
`text` | `textarea` | `text`
`file` | `input[type=file]` | `string` responding to file methods
`hidden` | `input[type=hidden]` | -
`integer` | `input[type=number]` | `integer`
`float` | `input[type=number]` | `float`
`decimal` | `input[type=number]` | `decimal`
`range` | `input[type=range]` | -
`datetime` | `datetime select` | `datetime/timestamp`
`date` | `date select` | `date`
`time` | `time select` | `time`
`select` | `select` | `belongs_to`/`has_many`/`has_and_belongs_to_many` associations
`radio_buttons` | collection of `input[type=radio]` | `belongs_to` associations
`check_boxes` | collection of `input[type=checkbox]` | `has_many`/`has_and_belongs_to_many` associations
`country` | `select` (countries as options) | `string` with `name =~ /country/`
`time_zone` | `select` (timezones as options) | `string` with `name =~ /time_zone/`
## Custom inputs
It is very easy to add custom inputs to **Simple Form**. 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(wrapper_options)
merged_input_options = merge_wrapper_options(input_html_options, wrapper_options)
"$ #{@builder.text_field(attribute_name, merged_input_options)}".html_safe
end
end
```
And use it in your views:
```ruby
f.input :money, as: :currency
```
Note, you may have to create the `app/inputs/` directory and restart your webserver.
You can also redefine existing **Simple Form** 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(wrapper_options)
template.content_tag(:div, super)
end
end
```
Or if you want to add a class to all the select fields you can do:
```ruby
# app/inputs/collection_select_input.rb
class CollectionSelectInput < SimpleForm::Inputs::CollectionSelectInput
def input_html_classes
super.push('chosen')
end
end
```
If needed, you can namespace your custom inputs in a module and tell **Simple Form** to look for
their definitions in this module. This can avoid conflicts with other form libraries (like Formtastic) that look up
the global context to find inputs definition too.
```ruby
# app/inputs/custom_inputs/numeric_input
module CustomInputs
class NumericInput < SimpleForm::Inputs::NumericInput
def input_html_classes
super.push('no-spinner')
end
end
end
```
And in the **SimpleForm** initializer :
```ruby
# config/simple_form.rb
config.custom_inputs_namespaces << "CustomInputs"
```
## Custom form builder
You can create a custom form builder that uses **Simple Form**.
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)
super(attribute_name, options.merge(label: false), &block)
end
end
```
## I18n
**Simple Form** uses all power of I18n API to lookup labels, hints, prompts 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: '****'
include_blanks:
user:
age: 'Rather not say'
prompts:
user:
gender: 'Select your gender'
```
And your forms will use this information to render the components for you.
**Simple Form** also lets you be more specific, separating lookups through actions.
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 **Simple Form** 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: '****'
```
**Simple Form** will always look for a default attribute translation under the "defaults" key if no
specific is found inside the model key.
In addition, **Simple Form** 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.
For `:prompt` and `:include_blank` the I18n lookup is optional and to enable it is necessary to pass
`:translate` as value.
```ruby
f.input :gender, prompt: :translate
```
**Simple Form** 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 **Simple Form** you could create an input
like this:
```ruby
f.input :gender, collection: [:male, :female]
```
And **Simple Form** 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 **Simple Form** 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`.
It should be noted that translations for labels, hints and placeholders for a namespaced model, e.g.
`Admin::User`, should be placed under `admin_user`, not under `admin/user`. This is different from
how translations for namespaced model and attribute names are defined:
```yaml
en:
activerecord:
models:
admin/user: User
attributes:
admin/user:
name: Name
```
They should be placed under `admin/user`. Form labels, hints and placeholders for those attributes,
though, should be placed under `admin_user`:
```yaml
en:
simple_form:
labels:
admin_user:
name: Name
```
This difference exists because **Simple Form** relies on `object_name` provided by Rails'
FormBuilder to determine the translation path for a given object instead of `i18n_key` from the
object itself. Thus, similarly, if a form for an `Admin::User` object is defined by calling
`simple_form_for @admin_user, as: :some_user`, **Simple Form** will look for translations
under `some_user` instead of `admin_user`.
## Configuration
**Simple Form** has several configuration options. You can read and change them in the initializer
created by **Simple Form**, so if you haven't executed the command below yet, please do:
`rails generate simple_form:install`
### The wrappers API
With **Simple Form** you can configure how your components will be rendered 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, wrap_with: { tag: :span, class: :hint }
b.use :error, wrap_with: { tag: :span, class: :error }
end
```
The _Form components_ will generate the form tags like labels, inputs, hints or errors contents.
The available components are:
```ruby
:label # The