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.
## Information
### Google Group
If you have any questions, comments, or concerns please use the Google Group instead of the GitHub Issues tracker:
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.
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, add a hint or even a placeholder:
If you want to pass the same :input_html 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_html will overwrite the defaults:
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:
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 %>
<%= 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:
SimpleForm also allows you to use label, hint, input_field, error and full_error helpers it provides (please take a look at the rdocs for each method for more info):
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 and :check_boxes. Those are added by SimpleForm to Rails set of form helpers (read Extra Helpers session below for more information).
* 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"
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`)
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:
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:
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 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 and check boxes as well:
```ruby
f.association :company, :as => :radio
f.association :roles, :as => :check_boxes
```
The association helper just invokes input under the hood, so all options available to :select, :radio and :check_boxes are also available to association. Additionally, you can specify the collection by hand, all together with the prompt:
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:
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
"<div>#{super}</div>".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:
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:
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:
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.
## 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`
## Maintainers
* Carlos Antonio da Silva (https://github.com/carlosantoniodasilva)
* Rafael Mendonça França (https://github.com/rafaelfranca)
