Posts tagged "simple_form"

We have been working on SimpleForm for some time since the last release and have got a lot of contributions from community. Now it is time for a new release with more HTML 5 compatibility plus some new cool features. So, without further ado, lets take a ride on the new stuff.

HTML 5

One of the most useful features coming in HTML 5, in my opinion, is the placeholder option. This option allows us to configure a text to be shown inside the input when it is empty. This is really nice to help the user while filling out forms. SimpleForm now gives us the possibility to pass in a placeholder option in the same way we are used to do with use hints:

<%= 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 %>

As you can see here, the placeholder is given as String, but it can also be fetched from I18n, as labels/hints does.

Another addition is the automatic lookup of min/max values from numericality validations, for number inputs. For instance:

class User
  validates_numericality_of :age, :greater_than_or_equal_to => 18,
    :less_than_or_equal_to => 99, :only_integer => true
end
<%= simple_form_for @user do |f| %>
  <%= f.input :age %>
<% end %>

Would generate an input with type number, and the min/max attributes configured with 18 and 99, respectively.

Besides that SimpleForm also adds:

  • the :required html attribute for required inputs (it is retrieved automatically from your presence validations);
  • the :search and :tel input types, with :tel mapping automatically for attributes matching /phone/.

Collections

From now on, radio and check box collections will wrap the input element inside the label, making it pretty straightforward to associate both elements. Besides that, SimpleForm now comes with two new configurations:

  • collection_wrapper_tag wraps the entire collection in the configured tag;
  • item_wrapper_tag wraps each item in the collection using the configured tag.

An example:

<%= simple_form_for @user do |f| %>
  <%= f.association :roles, :as => :check_boxes, 
    :collection_wrapper_tag => :ul, :item_wrapper_tag => :li %>
<% end %>

This should be kind of self explanatory =).

New input options

It’s now possible to give the :disabled option straight to the input, which will also add the disabled css class to both input and wrapper elements:

<%= simple_form_for @user do |f| %>
  <%= f.input :email, :disabled => true %>
<% end %>

And also the :components option, which will only render the given components in the given order:

<%= simple_form_for @user do |f| %>
  # Generates the label after the input, and ignores errors/hints/placeholders
  <%= f.input :email, :components => [:input, :label] %>
<% end %>

New configuration options

If you are not using any label / hint / placeholder with I18n, you can now completely disable the translation lookup of these components by setting the config.translate to false in your SimpleForm initializer. This should improve performance a bit in these cases.

Another nice improvement is the ability to add custom input mappings to SimpleForm. If you ever needed to map a specific attribute to a default input, now you can:

  config.input_mappings = { /_count$/ => :integer }

This configuration expects a hash containing a regexp to match as key, and the input type that will be used when the field name matches the regexp as value. In this example we match all attributes ending with _count, such as comments_count, to be rendered as integer input by SimpleForm.

New docs and mailing list

SimpleForm now has its own google group where you can ask questions, search for already answered questions and also help others. Besides that, you can also navigate and search the entire RDoc.

Wrapping up

As you can see, there are plenty of new and cool stuff in this release. We encourage you to take a look at the CHANGELOG and also review the README to see what else is available and some more examples.

And please, check out SimpleForm contributors, we want to thank everyone who is helping us to improve SimpleForm.

What about you? Do you want any cool feature in SimpleForm? Help us improve it by forking and sending us a pull request, we will be really glad to apply it. We hope to see your name in the contributors page soon!

Finally, in your opinion, what is the coolest feature SimpleForm has? And what idea you have you might want to be added to SimpleForm? Feel free to comment :D

Sometime ago we were working on a project together with a designer, and that specific application was full of forms, each one having a different layout, but most of them sharing the same features: inline errors, hints, specific label markup for required fields, etc. To start prototyping the application faster, we used the markup the designer created with similar forms, duplicating the code. But we don’t like code duplication, we weren’t feeling comfortable with it. So we decided to move on and create a tool to help us, that should be flexible enough to let us define the markup that fits better for each application, or even no extra markup at all. Here is SimpleForm!

SimpleForm inputs

From the README:

Forms made easy (for Rails)!

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.

As the README says, SimpleForm is a tool to help you build forms easily in Rails. Let’s see some examples:

<%= simple_form_for @user do |f| %>
  <%= f.input :username, :label => 'Your username please' %>
  <%= f.input :password, :hint => 'No special characters.' %>
  <%= f.input :remember_me, :as => :boolean %>
  <%= f.button :submit %>
<% end -%>

There are plenty of things going on here: we create a form using simple_form_for helper, then we use the :input method to create input elements based on column type. For instance, :username will create a default text input, while :password attribute will render an input type password. For the :username attribute, we are specifying a label manually. For :password, the label will be taken from I18n, and we are adding a hint message to the field. For :remember_me, we are explicitly saying to render it as a checkbox, using the :as => :boolean option (that is the default for boolean attributes). Also, there is a button helper that simply delegates to Rails helpers, in this case submit.

The output for a new @user would be:

<form action="/users" class="simple_form user" id="new_user" method="post">
  <div class="input string required">
    <label class="string required" for="user_username"><abbr title="required">*</abbr> Your username please</label>
    <input class="string required" id="user_username" maxlength="255" name="user[username]" size="50" type="text" />
  </div> 
  <div class="input password required">
    <label class="password required" for="user_password"><abbr title="required">*</abbr> Password</label>
    <input class="password required" id="user_password" name="user[password]" size="30" type="password" />
    <span class="hint">No special characters.</span>
  </div> 
  <div class="input boolean optional">
    <label class="boolean optional" for="user_remember_me"> Remember me</label>
    <input name="user[remember_me]" type="hidden" value="0" />
    <input class="boolean optional" id="user_remember_me" name="user[remember_me]" type="checkbox" value="1" />
  </div> 
  <input id="user_submit" name="commit" type="submit" value="Create User" /> 
</form>

You may have noticed there is some additional css classes added to the markup, like string and required. They are added automatically by SimpleForm to help us style and plug some javascript in. There are specific css classes for each available input type. Also, pay some attention to the label: inside it there is an abbr tag with an asterisk (*) showing that the field is required. SimpleForm uses the new validations reflection API from Rails 3 to check if the attribute has the presence validator, and mark the field as required if so. And we are able to say that a field is required or disable the required mark, by passing the option :required => true|false.

Furthermore, there is the hint tag for the :password attribute that SimpleForm creates based on the :hint option we have defined. Also notice that the gem has automatically added a div wrapper to each input, with the same css classes. SimpleForm allows us to configure this wrapper as well, using for instance p instead of div. We are going to see more about configuration later.

SimpleForm is already prepared to generate some of the new HTML 5 input tags, such as email, url and number inputs:

<%= simple_form_for @user do |f| %>
  <%= f.input :website, :as => :url %>
  <%= f.input :email %>
  <%= f.input :age, :hint => "This defaults to 'number' input based on field type" %>
  <%= f.button :submit %>
<% end -%>

Based on the attribute name, SimpleForm will generate url or email input types, and we can always set a specific type with the :as option. Numeric attributes will always be rendered as input type number.

Working with associations

SimpleForm adds a custom and straightforward method to render select tags for associations, called association. For now, consider our User belongs to a Company, and has and belongs to many Roles. Let’s go straight to the example:

<%= simple_form_for @user do |f| %>
  <%= f.input :name %>
  <%= f.association :company %>
  <%= f.association :roles %>
  <%= f.button :submit %>
<% end -%>

It will detect the association type and render a select tag for choosing the company, listing all companies in the database, and another select for roles, with multiple option enabled.

SimpleForm also has some add-ons, letting us render associations as a collection of radios or check boxes. Using the same example:

  f.association :company, :as => :radio
  f.association :roles, :as => :check_boxes

Now we are rendering a collection of radios for choosing the Company, and another collection of check boxes for choosing Roles.

Configuration

SimpleForm lets us do some customizations by running its install generator:

rails generate simple_form:install

# Output
  create  config/initializers/simple_form.rb
  create  config/locales/simple_form.en.yml
  create  lib/templates/erb/scaffold/_form.html.erb

As we can see, running this generator will copy an initializer file, responsible for configuring SimpleForm; a locale file, to let us change some I18n messages; and a form template inside our lib dir. This template will be used instead of the default Rails scaffold form template, so it will create our form already using SimpleForm. Easy, right?

Let’s take a look at some configuration options:

  • components: defines the components used by the form builder. We can remove any of them, change the order, or add new ones. Defaults to [ :label, :input, :hint, :error ].
  • hint_tag: tag used for hints, defaults to span.
  • error_tag: tag used for errors, defaults to span.
  • wrapper_tag: tag used as wrapper to all inputs, defaults to div
  • label_text: determines how the label text should be generated altogether with the required text. It must be a lambda/proc that receives both label and required texts. Defaults to "required label".

There are a lot more options available in the initializer file, such as default input size and priority countries for generating country selects. Also, the locale file lets us determine the required text and mark, or even the entire required html tag.

Internationalization

SimpleForm is ready for I18n, supporting labels and hints. In addition, it lets us set different content for each action, new and edit. Here is an example locale file:

  en:
    simple_form:
      labels:
        user:
          username: 'User name'
          password: 'Password'
          edit:
            username: 'Change user name'
            password: 'Change password'
      hints:
        user:
          username: 'User name to sign in.'
          password: 'No special characters, please.'

Simple, right? If it does not find any specific translation using I18n for the label, it will fallback to human_attribute_name.

Here we go!

SimpleForm has much more to offer. We would like to invite you to take a better look at the examples and possibilities. Remember, SimpleForm aims to be flexible and powerful to help you easily build forms, without saying how you should create your markup.

Also, feel free to explore the source code and extend SimpleForm even further. Since it’s based on components, creating a new component which moves the current hints to inside the input (using javascript or the new placehoder attribute in HTML 5), should be easy!

It’s worth saying SimpleForm is Rails 3 compatible in the master branch. If you are using Rails 2.3.x, there is a v1.0 branch and version that you might want to take a look.

SimpleForm has been helping us a lot so far, we hope you enjoy it. Moreover, we would like to enjoy other tools that help your productivity day by day, please leave a comment and let us know, we would appreciate a lot!