+```
+
+#### auto_discovery_link_tag
+
+Returns a link tag that browsers and feed readers can use to auto-detect an RSS, Atom, or JSON feed.
+
+```ruby
+auto_discovery_link_tag(:rss, "http://www.example.com/feed.rss", { title: "RSS Feed" }) # =>
+
+```
+
+#### image_path
+
+Computes the path to an image asset in the `app/assets/images` directory. Full paths from the document root will be passed through. Used internally by `image_tag` to build the image path.
+
+```ruby
+image_path("edit.png") # => /assets/edit.png
+```
+
+Fingerprint will be added to the filename if config.assets.digest is set to true.
+
+```ruby
+image_path("edit.png") # => /assets/edit-2d1a2db63fc738690021fedb5a65b68e.png
+```
+
+#### image_url
+
+Computes the URL to an image asset in the `app/assets/images` directory. This will call `image_path` internally and merge with your current host or your asset host.
+
+```ruby
+image_url("edit.png") # => http://www.example.com/assets/edit.png
+```
+
+#### image_tag
+
+Returns an HTML image tag for the source. The source can be a full path or a file that exists in your `app/assets/images` directory.
+
+```ruby
+image_tag("icon.png") # => 
+```
+
+#### javascript_include_tag
+
+Returns an HTML script tag for each of the sources provided. You can pass in the filename (`.js` extension is optional) of JavaScript files that exist in your `app/assets/javascripts` directory for inclusion into the current page or you can pass the full path relative to your document root.
+
+```ruby
+javascript_include_tag "common" # =>
+```
+
+#### javascript_path
+
+Computes the path to a JavaScript asset in the `app/assets/javascripts` directory. If the source filename has no extension, `.js` will be appended. Full paths from the document root will be passed through. Used internally by `javascript_include_tag` to build the script path.
+
+```ruby
+javascript_path "common" # => /assets/common.js
+```
+
+#### javascript_url
+
+Computes the URL to a JavaScript asset in the `app/assets/javascripts` directory. This will call `javascript_path` internally and merge with your current host or your asset host.
+
+```ruby
+javascript_url "common" # => http://www.example.com/assets/common.js
+```
+
+#### stylesheet_link_tag
+
+Returns a stylesheet link tag for the sources specified as arguments. If you don't specify an extension, `.css` will be appended automatically.
+
+```ruby
+stylesheet_link_tag "application" # =>
+```
+
+#### stylesheet_path
+
+Computes the path to a stylesheet asset in the `app/assets/stylesheets` directory. If the source filename has no extension, `.css` will be appended. Full paths from the document root will be passed through. Used internally by `stylesheet_link_tag` to build the stylesheet path.
+
+```ruby
+stylesheet_path "application" # => /assets/application.css
+```
+
+#### stylesheet_url
+
+Computes the URL to a stylesheet asset in the `app/assets/stylesheets` directory. This will call `stylesheet_path` internally and merge with your current host or your asset host.
+
+```ruby
+stylesheet_url "application" # => http://www.example.com/assets/application.css
+```
+
+### AtomFeedHelper
+
+#### atom_feed
+
+This helper makes building an Atom feed easy. Here's a full usage example:
+
+**config/routes.rb**
+
+```ruby
+resources :articles
+```
+
+**app/controllers/articles_controller.rb**
+
+```ruby
+def index
+ @articles = Article.all
+
+ respond_to do |format|
+ format.html
+ format.atom
+ end
+end
+```
+
+**app/views/articles/index.atom.builder**
+
+```ruby
+atom_feed do |feed|
+ feed.title("Articles Index")
+ feed.updated(@articles.first.created_at)
+
+ @articles.each do |article|
+ feed.entry(article) do |entry|
+ entry.title(article.title)
+ entry.content(article.body, type: 'html')
+
+ entry.author do |author|
+ author.name(article.author_name)
+ end
+ end
+ end
+end
+```
+
+### BenchmarkHelper
+
+#### benchmark
+
+Allows you to measure the execution time of a block in a template and records the result to the log. Wrap this block around expensive operations or possible bottlenecks to get a time reading for the operation.
+
+```html+erb
+<% benchmark "Process data files" do %>
+ <%= expensive_files_operation %>
+<% end %>
+```
+
+This would add something like "Process data files (0.34523)" to the log, which you can then use to compare timings when optimizing your code.
+
+### CacheHelper
+
+#### cache
+
+A method for caching fragments of a view rather than an entire action or page. This technique is useful for caching pieces like menus, lists of news topics, static HTML fragments, and so on. This method takes a block that contains the content you wish to cache. See `AbstractController::Caching::Fragments` for more information.
+
+```erb
+<% cache do %>
+ <%= render "shared/footer" %>
+<% end %>
+```
+
+### CaptureHelper
+
+#### capture
+
+The `capture` method allows you to extract part of a template into a variable. You can then use this variable anywhere in your templates or layout.
+
+```html+erb
+<% @greeting = capture do %>
+ Welcome! The date and time is <%= Time.now %>
+<% end %> +``` + +The captured variable can then be used anywhere else. + +```html+erb + + +Welcome! The date and time is <%= Time.now %>
+ + +``` + +**app/views/articles/special.html.erb** + +```html+erb +This is a special page.
+ +<% content_for :special_script do %> + +<% end %> +``` + +### DateHelper + +#### date_select + +Returns a set of select tags (one for year, month, and day) pre-selected for accessing a specified date-based attribute. + +```ruby +date_select("article", "published_on") +``` + +#### datetime_select + +Returns a set of select tags (one for year, month, day, hour, and minute) pre-selected for accessing a specified datetime-based attribute. + +```ruby +datetime_select("article", "published_on") +``` + +#### distance_of_time_in_words + +Reports the approximate distance in time between two Time or Date objects or integers as seconds. Set `include_seconds` to true if you want more detailed approximations. + +```ruby +distance_of_time_in_words(Time.now, Time.now + 15.seconds) # => less than a minute +distance_of_time_in_words(Time.now, Time.now + 15.seconds, include_seconds: true) # => less than 20 seconds +``` + +#### select_date + +Returns a set of HTML select-tags (one for year, month, and day) pre-selected with the `date` provided. + +```ruby +# Generates a date select that defaults to the date provided (six days after today) +select_date(Time.today + 6.days) + +# Generates a date select that defaults to today (no specified date) +select_date() +``` + +#### select_datetime + +Returns a set of HTML select-tags (one for year, month, day, hour, and minute) pre-selected with the `datetime` provided. + +```ruby +# Generates a datetime select that defaults to the datetime provided (four days after today) +select_datetime(Time.now + 4.days) + +# Generates a datetime select that defaults to today (no specified datetime) +select_datetime() +``` + +#### select_day + +Returns a select tag with options for each of the days 1 through 31 with the current day selected. + +```ruby +# Generates a select field for days that defaults to the day for the date provided +select_day(Time.today + 2.days) + +# Generates a select field for days that defaults to the number given +select_day(5) +``` + +#### select_hour + +Returns a select tag with options for each of the hours 0 through 23 with the current hour selected. + +```ruby +# Generates a select field for hours that defaults to the hours for the time provided +select_hour(Time.now + 6.hours) +``` + +#### select_minute + +Returns a select tag with options for each of the minutes 0 through 59 with the current minute selected. + +```ruby +# Generates a select field for minutes that defaults to the minutes for the time provided. +select_minute(Time.now + 10.minutes) +``` + +#### select_month + +Returns a select tag with options for each of the months January through December with the current month selected. + +```ruby +# Generates a select field for months that defaults to the current month +select_month(Date.today) +``` + +#### select_second + +Returns a select tag with options for each of the seconds 0 through 59 with the current second selected. + +```ruby +# Generates a select field for seconds that defaults to the seconds for the time provided +select_second(Time.now + 16.seconds) +``` + +#### select_time + +Returns a set of HTML select-tags (one for hour and minute). + +```ruby +# Generates a time select that defaults to the time provided +select_time(Time.now) +``` + +#### select_year + +Returns a select tag with options for each of the five years on each side of the current, which is selected. The five year radius can be changed using the `:start_year` and `:end_year` keys in the `options`. + +```ruby +# Generates a select field for five years on either side of Date.today that defaults to the current year +select_year(Date.today) + +# Generates a select field from 1900 to 2009 that defaults to the current year +select_year(Date.today, start_year: 1900, end_year: 2009) +``` + +#### time_ago_in_words + +Like `distance_of_time_in_words`, but where `to_time` is fixed to `Time.now`. + +```ruby +time_ago_in_words(3.minutes.from_now) # => 3 minutes +``` + +#### time_select + +Returns a set of select tags (one for hour, minute, and optionally second) pre-selected for accessing a specified time-based attribute. The selects are prepared for multi-parameter assignment to an Active Record object. + +```ruby +# Creates a time select tag that, when POSTed, will be stored in the order variable in the submitted attribute +time_select("order", "submitted") +``` + +### DebugHelper + +Returns a `pre` tag that has object dumped by YAML. This creates a very readable way to inspect an object. + +```ruby +my_hash = { 'first' => 1, 'second' => 'two', 'third' => [1,2,3] } +debug(my_hash) +``` + +```html +--- +first: 1 +second: two +third: +- 1 +- 2 +- 3 ++``` + +### FormHelper + +Form helpers are designed to make working with models much easier compared to using just standard HTML elements by providing a set of methods for creating forms based on your models. This helper generates the HTML for forms, providing a method for each sort of input (e.g., text, password, select, and so on). When the form is submitted (i.e., when the user hits the submit button or form.submit is called via JavaScript), the form inputs will be bundled into the params object and passed back to the controller. + +There are two types of form helpers: those that specifically work with model attributes and those that don't. This helper deals with those that work with model attributes; to see an example of form helpers that don't work with model attributes, check the `ActionView::Helpers::FormTagHelper` documentation. + +The core method of this helper, `form_with`, gives you the ability to create a form for a model instance; for example, let's say that you have a model Person and want to create a new instance of it: + +```html+erb + +<%= form_with model: @person do |form| %> + <%= form.text_field :first_name %> + <%= form.text_field :last_name %> + <%= submit_tag 'Create' %> +<% end %> +``` + +The HTML generated for this would be: + +```html + +``` + +The params object created when this form is submitted would look like: + +```ruby +{"utf8" => "✓", "authenticity_token" => "lTuvBzs7ANygT0NFinXj98tfw3Emfm65wwYLbUvoWsK2pngccIQSUorM2C035M9dZswXgWTvKwFS8W5TVblpYw==", "person" => {"first_name" => "William", "last_name" => "Smith"}, "commit" => "Create", "controller" => "people", "action" => "create"} +``` + +The params hash has a nested person value, which can therefore be accessed with `params[:person]` in the controller. + +#### check_box + +Returns a checkbox tag tailored for accessing a specified attribute. + +```ruby +# Let's say that @article.validated? is 1: +check_box("article", "validated") +# => +# +``` + +#### fields_for + +Creates a scope around a specific model object. This makes `fields_for` suitable for specifying additional model objects in the same form: + +```html+erb +<%= form_with model: @person do |person_form| %> + First name: <%= person_form.text_field :first_name %> + Last name : <%= person_form.text_field :last_name %> + + <%= fields_for @person.permission do |permission_fields| %> + Admin? : <%= permission_fields.check_box :admin %> + <% end %> +<% end %> +``` + +#### file_field + +Returns a file upload input tag tailored for accessing a specified attribute. + +```ruby +file_field(:user, :avatar) +# => +``` + +#### form_with + +Creates a form builder to work with. If a `model` argument is specified, form fields will be scoped to that model, and form field values will be prepopulated with corresponding model attributes. + +```html+erb +<%= form_with model: @article do |form| %> + <%= form.label :title, 'Title' %>: + <%= form.text_field :title %>
<%= text_field_tag 'name' %>
+<% end %> +# => +``` + +#### file_field_tag + +Creates a file upload field. + +```html+erb +<%= form_with url: new_account_avatar_path(@account), multipart: true do %> + <%= file_field_tag 'avatar' %> + <%= submit_tag %> +<% end %> +``` + +Example output: + +```ruby +file_field_tag 'attachment' +# => +``` + +#### hidden_field_tag + +Creates a hidden form input field used to transmit data that would be lost due to HTTP's statelessness or data that should be hidden from the user. + +```ruby +hidden_field_tag 'token', 'VUBJKB23UIVI1UU1VOBVI@' +# => +``` + +#### image_submit_tag + +Displays an image which when clicked will submit the form. + +```ruby +image_submit_tag("login.png") +# => +``` + +#### label_tag + +Creates a label field. + +```ruby +label_tag 'name' +# => +``` + +#### password_field_tag + +Creates a password field, a masked text field that will hide the users input behind a mask character. + +```ruby +password_field_tag 'pass' +# => +``` + +#### radio_button_tag + +Creates a radio button; use groups of radio buttons named the same to allow users to select from a group of options. + +```ruby +radio_button_tag 'favorite_color', 'maroon' +# => +``` + +#### select_tag + +Creates a dropdown selection box. + +```ruby +select_tag "people", "" +# => +``` + +#### submit_tag + +Creates a submit button with the text provided as the caption. + +```ruby +submit_tag "Publish this article" +# => +``` + +#### text_area_tag + +Creates a text input area; use a textarea for longer text inputs such as blog posts or descriptions. + +```ruby +text_area_tag 'article' +# => +``` + +#### text_field_tag + +Creates a standard text field; use these text fields to input smaller chunks of text like a username or a search query. + +```ruby +text_field_tag 'name' +# => +``` + +#### email_field_tag + +Creates a standard input field of email type. + +```ruby +email_field_tag 'email' +# => +``` + +#### url_field_tag + +Creates a standard input field of url type. + +```ruby +url_field_tag 'url' +# => +``` + +#### date_field_tag + +Creates a standard input field of date type. + +```ruby +date_field_tag "dob" +# => +``` + +### JavaScriptHelper + +Provides functionality for working with JavaScript in your views. + +#### escape_javascript + +Escape carrier returns and single and double quotes for JavaScript segments. + +#### javascript_tag + +Returns a JavaScript tag wrapping the provided code. + +```ruby +javascript_tag "alert('All is good')" +``` + +```html + +``` + +### NumberHelper + +Provides methods for converting numbers into formatted strings. Methods are provided for phone numbers, currency, percentage, precision, positional notation, and file size. + +#### number_to_currency + +Formats a number into a currency string (e.g., $13.65). + +```ruby +number_to_currency(1234567890.50) # => $1,234,567,890.50 +``` + +#### number_to_human_size + +Formats the bytes in size into a more understandable representation; useful for reporting file sizes to users. + +```ruby +number_to_human_size(1234) # => 1.2 KB +number_to_human_size(1234567) # => 1.2 MB +``` + +#### number_to_percentage + +Formats a number as a percentage string. + +```ruby +number_to_percentage(100, precision: 0) # => 100% +``` + +#### number_to_phone + +Formats a number into a phone number (US by default). + +```ruby +number_to_phone(1235551234) # => 123-555-1234 +``` + +#### number_with_delimiter + +Formats a number with grouped thousands using a delimiter. + +```ruby +number_with_delimiter(12345678) # => 12,345,678 +``` + +#### number_with_precision + +Formats a number with the specified level of `precision`, which defaults to 3. + +```ruby +number_with_precision(111.2345) # => 111.235 +number_with_precision(111.2345, precision: 2) # => 111.23 +``` + +### SanitizeHelper + +The SanitizeHelper module provides a set of methods for scrubbing text of undesired HTML elements. + +#### sanitize + +This sanitize helper will HTML encode all tags and strip all attributes that aren't specifically allowed. + +```ruby +sanitize @article.body +``` + +If either the `:attributes` or `:tags` options are passed, only the mentioned attributes and tags are allowed and nothing else. + +```ruby +sanitize @article.body, tags: %w(table tr td), attributes: %w(id class style) +``` + +To change defaults for multiple uses, for example adding table tags to the default: + +```ruby +class Application < Rails::Application + config.action_view.sanitized_allowed_tags = 'table', 'tr', 'td' +end +``` + +#### sanitize_css(style) + +Sanitizes a block of CSS code. + +#### strip_links(html) +Strips all link tags from text leaving just the link text. + +```ruby +strip_links('Ruby on Rails') +# => Ruby on Rails +``` + +```ruby +strip_links('emails to me@email.com.') +# => emails to me@email.com. +``` + +```ruby +strip_links('Blog: Visit.') +# => Blog: Visit. +``` + +#### strip_tags(html) + +Strips all HTML tags from the html, including comments. +This functionality is powered by the rails-html-sanitizer gem. + +```ruby +strip_tags("Strip these tags!") +# => Strip these tags! +``` + +```ruby +strip_tags("Bold no more! See more") +# => Bold no more! See more +``` + +NB: The output may still contain unescaped '<', '>', '&' characters and confuse browsers. + +### UrlHelper + +Provides methods to make links and get URLs that depend on the routing subsystem. + +#### url_for + +Returns the URL for the set of `options` provided. + +##### Examples + +```ruby +url_for @profile +# => /profiles/1 + +url_for [ @hotel, @booking, page: 2, line: 3 ] +# => /hotels/1/bookings/1?line=3&page=2 +``` + +#### link_to + +Links to a URL derived from `url_for` under the hood. Primarily used to +create RESTful resource links, which for this example, boils down to +when passing models to `link_to`. + +**Examples** + +```ruby +link_to "Profile", @profile +# => Profile +``` + +You can use a block as well if your link target can't fit in the name parameter. ERB example: + +```html+erb +<%= link_to @profile do %> + <%= @profile.name %> -- Check it out! +<% end %> +``` + +would output: + +```html + + David -- Check it out! + +``` + +See [the API Doc for more info](https://api.rubyonrails.org/classes/ActionView/Helpers/UrlHelper.html#method-i-link_to) + +#### button_to + +Generates a form that submits to the passed URL. The form has a submit button +with the value of the `name`. + +##### Examples + +```html+erb +<%= button_to "Sign in", sign_in_path %> +``` + +would roughly output something like: + +```html + +``` + +See [the API Doc for more info](https://api.rubyonrails.org/classes/ActionView/Helpers/UrlHelper.html#method-i-button_to) + +### CsrfHelper + +Returns meta tags "csrf-param" and "csrf-token" with the name of the cross-site +request forgery protection parameter and token, respectively. + +```html +<%= csrf_meta_tags %> +``` + +NOTE: Regular forms generate hidden fields so they do not use these tags. More +details can be found in the [Rails Security Guide](security.html#cross-site-request-forgery-csrf). diff --git a/guides/source/action_view_overview.md b/guides/source/action_view_overview.md index c8989d2db811d..af37132285dd2 100644 --- a/guides/source/action_view_overview.md +++ b/guides/source/action_view_overview.md @@ -7,7 +7,6 @@ After reading this guide, you will know: * What Action View is and how to use it with Rails. * How best to use templates, partials, and layouts. -* What helpers are provided by Action View. * How to use localized views. -------------------------------------------------------------------------------- @@ -399,1182 +398,20 @@ append_view_path "app/views/direct" This will add `app/views/direct` to the end of the lookup paths. -Overview of helpers provided by Action View -------------------------------------------- +Helpers +------- -WIP: Not all the helpers are listed here. For a full list see the [API documentation](https://api.rubyonrails.org/classes/ActionView/Helpers.html) +Rails provides many helper methods to use with Action View. These include methods for: -The following is only a brief overview summary of the helpers available in Action View. It's recommended that you review the [API Documentation](https://api.rubyonrails.org/classes/ActionView/Helpers.html), which covers all of the helpers in more detail, but this should serve as a good starting point. +* Formatting dates, strings and numbers +* Creating HTML links to images, videos, stylesheets, etc... +* Sanitizing content +* Creating forms +* Localizing content -### AssetTagHelper - -This module provides methods for generating HTML that links views to assets such as images, JavaScript files, stylesheets, and feeds. - -By default, Rails links to these assets on the current host in the public folder, but you can direct Rails to link to assets from a dedicated assets server by setting `config.action_controller.asset_host` in the application configuration, typically in `config/environments/production.rb`. For example, let's say your asset host is `assets.example.com`: - -```ruby -config.action_controller.asset_host = "assets.example.com" -image_tag("rails.png") # =>
-```
-
-#### auto_discovery_link_tag
-
-Returns a link tag that browsers and feed readers can use to auto-detect an RSS, Atom, or JSON feed.
-
-```ruby
-auto_discovery_link_tag(:rss, "http://www.example.com/feed.rss", { title: "RSS Feed" }) # =>
-
-```
-
-#### image_path
-
-Computes the path to an image asset in the `app/assets/images` directory. Full paths from the document root will be passed through. Used internally by `image_tag` to build the image path.
-
-```ruby
-image_path("edit.png") # => /assets/edit.png
-```
-
-Fingerprint will be added to the filename if config.assets.digest is set to true.
-
-```ruby
-image_path("edit.png") # => /assets/edit-2d1a2db63fc738690021fedb5a65b68e.png
-```
-
-#### image_url
-
-Computes the URL to an image asset in the `app/assets/images` directory. This will call `image_path` internally and merge with your current host or your asset host.
-
-```ruby
-image_url("edit.png") # => http://www.example.com/assets/edit.png
-```
-
-#### image_tag
-
-Returns an HTML image tag for the source. The source can be a full path or a file that exists in your `app/assets/images` directory.
-
-```ruby
-image_tag("icon.png") # =>
-```
-
-#### javascript_include_tag
-
-Returns an HTML script tag for each of the sources provided. You can pass in the filename (`.js` extension is optional) of JavaScript files that exist in your `app/assets/javascripts` directory for inclusion into the current page or you can pass the full path relative to your document root.
-
-```ruby
-javascript_include_tag "common" # =>
-```
-
-#### javascript_path
-
-Computes the path to a JavaScript asset in the `app/assets/javascripts` directory. If the source filename has no extension, `.js` will be appended. Full paths from the document root will be passed through. Used internally by `javascript_include_tag` to build the script path.
-
-```ruby
-javascript_path "common" # => /assets/common.js
-```
-
-#### javascript_url
-
-Computes the URL to a JavaScript asset in the `app/assets/javascripts` directory. This will call `javascript_path` internally and merge with your current host or your asset host.
-
-```ruby
-javascript_url "common" # => http://www.example.com/assets/common.js
-```
-
-#### stylesheet_link_tag
-
-Returns a stylesheet link tag for the sources specified as arguments. If you don't specify an extension, `.css` will be appended automatically.
-
-```ruby
-stylesheet_link_tag "application" # =>
-```
-
-#### stylesheet_path
-
-Computes the path to a stylesheet asset in the `app/assets/stylesheets` directory. If the source filename has no extension, `.css` will be appended. Full paths from the document root will be passed through. Used internally by `stylesheet_link_tag` to build the stylesheet path.
-
-```ruby
-stylesheet_path "application" # => /assets/application.css
-```
-
-#### stylesheet_url
-
-Computes the URL to a stylesheet asset in the `app/assets/stylesheets` directory. This will call `stylesheet_path` internally and merge with your current host or your asset host.
-
-```ruby
-stylesheet_url "application" # => http://www.example.com/assets/application.css
-```
-
-### AtomFeedHelper
-
-#### atom_feed
-
-This helper makes building an Atom feed easy. Here's a full usage example:
-
-**config/routes.rb**
-
-```ruby
-resources :articles
-```
-
-**app/controllers/articles_controller.rb**
-
-```ruby
-def index
- @articles = Article.all
-
- respond_to do |format|
- format.html
- format.atom
- end
-end
-```
-
-**app/views/articles/index.atom.builder**
-
-```ruby
-atom_feed do |feed|
- feed.title("Articles Index")
- feed.updated(@articles.first.created_at)
-
- @articles.each do |article|
- feed.entry(article) do |entry|
- entry.title(article.title)
- entry.content(article.body, type: 'html')
-
- entry.author do |author|
- author.name(article.author_name)
- end
- end
- end
-end
-```
-
-### BenchmarkHelper
-
-#### benchmark
-
-Allows you to measure the execution time of a block in a template and records the result to the log. Wrap this block around expensive operations or possible bottlenecks to get a time reading for the operation.
-
-```html+erb
-<% benchmark "Process data files" do %>
- <%= expensive_files_operation %>
-<% end %>
-```
-
-This would add something like "Process data files (0.34523)" to the log, which you can then use to compare timings when optimizing your code.
-
-### CacheHelper
-
-#### cache
-
-A method for caching fragments of a view rather than an entire action or page. This technique is useful for caching pieces like menus, lists of news topics, static HTML fragments, and so on. This method takes a block that contains the content you wish to cache. See `AbstractController::Caching::Fragments` for more information.
-
-```erb
-<% cache do %>
- <%= render "shared/footer" %>
-<% end %>
-```
-
-### CaptureHelper
-
-#### capture
-
-The `capture` method allows you to extract part of a template into a variable. You can then use this variable anywhere in your templates or layout.
-
-```html+erb
-<% @greeting = capture do %>
- Welcome! The date and time is <%= Time.now %>
-<% end %> -``` - -The captured variable can then be used anywhere else. - -```html+erb - - -Welcome! The date and time is <%= Time.now %>
- - -``` - -**app/views/articles/special.html.erb** - -```html+erb -This is a special page.
- -<% content_for :special_script do %> - -<% end %> -``` - -### DateHelper - -#### date_select - -Returns a set of select tags (one for year, month, and day) pre-selected for accessing a specified date-based attribute. - -```ruby -date_select("article", "published_on") -``` - -#### datetime_select - -Returns a set of select tags (one for year, month, day, hour, and minute) pre-selected for accessing a specified datetime-based attribute. - -```ruby -datetime_select("article", "published_on") -``` - -#### distance_of_time_in_words - -Reports the approximate distance in time between two Time or Date objects or integers as seconds. Set `include_seconds` to true if you want more detailed approximations. - -```ruby -distance_of_time_in_words(Time.now, Time.now + 15.seconds) # => less than a minute -distance_of_time_in_words(Time.now, Time.now + 15.seconds, include_seconds: true) # => less than 20 seconds -``` - -#### select_date - -Returns a set of HTML select-tags (one for year, month, and day) pre-selected with the `date` provided. - -```ruby -# Generates a date select that defaults to the date provided (six days after today) -select_date(Time.today + 6.days) - -# Generates a date select that defaults to today (no specified date) -select_date() -``` - -#### select_datetime - -Returns a set of HTML select-tags (one for year, month, day, hour, and minute) pre-selected with the `datetime` provided. - -```ruby -# Generates a datetime select that defaults to the datetime provided (four days after today) -select_datetime(Time.now + 4.days) - -# Generates a datetime select that defaults to today (no specified datetime) -select_datetime() -``` - -#### select_day - -Returns a select tag with options for each of the days 1 through 31 with the current day selected. - -```ruby -# Generates a select field for days that defaults to the day for the date provided -select_day(Time.today + 2.days) - -# Generates a select field for days that defaults to the number given -select_day(5) -``` - -#### select_hour - -Returns a select tag with options for each of the hours 0 through 23 with the current hour selected. - -```ruby -# Generates a select field for hours that defaults to the hours for the time provided -select_hour(Time.now + 6.hours) -``` - -#### select_minute - -Returns a select tag with options for each of the minutes 0 through 59 with the current minute selected. - -```ruby -# Generates a select field for minutes that defaults to the minutes for the time provided. -select_minute(Time.now + 10.minutes) -``` - -#### select_month - -Returns a select tag with options for each of the months January through December with the current month selected. - -```ruby -# Generates a select field for months that defaults to the current month -select_month(Date.today) -``` - -#### select_second - -Returns a select tag with options for each of the seconds 0 through 59 with the current second selected. - -```ruby -# Generates a select field for seconds that defaults to the seconds for the time provided -select_second(Time.now + 16.seconds) -``` - -#### select_time - -Returns a set of HTML select-tags (one for hour and minute). - -```ruby -# Generates a time select that defaults to the time provided -select_time(Time.now) -``` - -#### select_year - -Returns a select tag with options for each of the five years on each side of the current, which is selected. The five year radius can be changed using the `:start_year` and `:end_year` keys in the `options`. - -```ruby -# Generates a select field for five years on either side of Date.today that defaults to the current year -select_year(Date.today) - -# Generates a select field from 1900 to 2009 that defaults to the current year -select_year(Date.today, start_year: 1900, end_year: 2009) -``` - -#### time_ago_in_words - -Like `distance_of_time_in_words`, but where `to_time` is fixed to `Time.now`. - -```ruby -time_ago_in_words(3.minutes.from_now) # => 3 minutes -``` - -#### time_select - -Returns a set of select tags (one for hour, minute, and optionally second) pre-selected for accessing a specified time-based attribute. The selects are prepared for multi-parameter assignment to an Active Record object. - -```ruby -# Creates a time select tag that, when POSTed, will be stored in the order variable in the submitted attribute -time_select("order", "submitted") -``` - -### DebugHelper - -Returns a `pre` tag that has object dumped by YAML. This creates a very readable way to inspect an object. - -```ruby -my_hash = { 'first' => 1, 'second' => 'two', 'third' => [1,2,3] } -debug(my_hash) -``` - -```html ---- -first: 1 -second: two -third: -- 1 -- 2 -- 3 --``` - -### FormHelper - -Form helpers are designed to make working with models much easier compared to using just standard HTML elements by providing a set of methods for creating forms based on your models. This helper generates the HTML for forms, providing a method for each sort of input (e.g., text, password, select, and so on). When the form is submitted (i.e., when the user hits the submit button or form.submit is called via JavaScript), the form inputs will be bundled into the params object and passed back to the controller. - -There are two types of form helpers: those that specifically work with model attributes and those that don't. This helper deals with those that work with model attributes; to see an example of form helpers that don't work with model attributes, check the `ActionView::Helpers::FormTagHelper` documentation. - -The core method of this helper, `form_with`, gives you the ability to create a form for a model instance; for example, let's say that you have a model Person and want to create a new instance of it: - -```html+erb - -<%= form_with model: @person do |form| %> - <%= form.text_field :first_name %> - <%= form.text_field :last_name %> - <%= submit_tag 'Create' %> -<% end %> -``` - -The HTML generated for this would be: - -```html - -``` - -The params object created when this form is submitted would look like: - -```ruby -{"utf8" => "✓", "authenticity_token" => "lTuvBzs7ANygT0NFinXj98tfw3Emfm65wwYLbUvoWsK2pngccIQSUorM2C035M9dZswXgWTvKwFS8W5TVblpYw==", "person" => {"first_name" => "William", "last_name" => "Smith"}, "commit" => "Create", "controller" => "people", "action" => "create"} -``` - -The params hash has a nested person value, which can therefore be accessed with `params[:person]` in the controller. - -#### check_box - -Returns a checkbox tag tailored for accessing a specified attribute. - -```ruby -# Let's say that @article.validated? is 1: -check_box("article", "validated") -# => -# -``` - -#### fields_for - -Creates a scope around a specific model object. This makes `fields_for` suitable for specifying additional model objects in the same form: - -```html+erb -<%= form_with model: @person do |person_form| %> - First name: <%= person_form.text_field :first_name %> - Last name : <%= person_form.text_field :last_name %> - - <%= fields_for @person.permission do |permission_fields| %> - Admin? : <%= permission_fields.check_box :admin %> - <% end %> -<% end %> -``` - -#### file_field - -Returns a file upload input tag tailored for accessing a specified attribute. - -```ruby -file_field(:user, :avatar) -# => -``` - -#### form_with - -Creates a form builder to work with. If a `model` argument is specified, form fields will be scoped to that model, and form field values will be prepopulated with corresponding model attributes. - -```html+erb -<%= form_with model: @article do |form| %> - <%= form.label :title, 'Title' %>: - <%= form.text_field :title %>
<%= text_field_tag 'name' %>
-<% end %> -# => -``` - -#### file_field_tag - -Creates a file upload field. - -```html+erb -<%= form_with url: new_account_avatar_path(@account), multipart: true do %> - <%= file_field_tag 'avatar' %> - <%= submit_tag %> -<% end %> -``` - -Example output: - -```ruby -file_field_tag 'attachment' -# => -``` - -#### hidden_field_tag - -Creates a hidden form input field used to transmit data that would be lost due to HTTP's statelessness or data that should be hidden from the user. - -```ruby -hidden_field_tag 'token', 'VUBJKB23UIVI1UU1VOBVI@' -# => -``` - -#### image_submit_tag - -Displays an image which when clicked will submit the form. - -```ruby -image_submit_tag("login.png") -# => -``` - -#### label_tag - -Creates a label field. - -```ruby -label_tag 'name' -# => -``` - -#### password_field_tag - -Creates a password field, a masked text field that will hide the users input behind a mask character. - -```ruby -password_field_tag 'pass' -# => -``` - -#### radio_button_tag - -Creates a radio button; use groups of radio buttons named the same to allow users to select from a group of options. - -```ruby -radio_button_tag 'favorite_color', 'maroon' -# => -``` - -#### select_tag - -Creates a dropdown selection box. - -```ruby -select_tag "people", "" -# => -``` - -#### submit_tag - -Creates a submit button with the text provided as the caption. - -```ruby -submit_tag "Publish this article" -# => -``` - -#### text_area_tag - -Creates a text input area; use a textarea for longer text inputs such as blog posts or descriptions. - -```ruby -text_area_tag 'article' -# => -``` - -#### text_field_tag - -Creates a standard text field; use these text fields to input smaller chunks of text like a username or a search query. - -```ruby -text_field_tag 'name' -# => -``` - -#### email_field_tag - -Creates a standard input field of email type. - -```ruby -email_field_tag 'email' -# => -``` - -#### url_field_tag - -Creates a standard input field of url type. - -```ruby -url_field_tag 'url' -# => -``` - -#### date_field_tag - -Creates a standard input field of date type. - -```ruby -date_field_tag "dob" -# => -``` - -### JavaScriptHelper - -Provides functionality for working with JavaScript in your views. - -#### escape_javascript - -Escape carrier returns and single and double quotes for JavaScript segments. - -#### javascript_tag - -Returns a JavaScript tag wrapping the provided code. - -```ruby -javascript_tag "alert('All is good')" -``` - -```html - -``` - -### NumberHelper - -Provides methods for converting numbers into formatted strings. Methods are provided for phone numbers, currency, percentage, precision, positional notation, and file size. - -#### number_to_currency - -Formats a number into a currency string (e.g., $13.65). - -```ruby -number_to_currency(1234567890.50) # => $1,234,567,890.50 -``` - -#### number_to_human_size - -Formats the bytes in size into a more understandable representation; useful for reporting file sizes to users. - -```ruby -number_to_human_size(1234) # => 1.2 KB -number_to_human_size(1234567) # => 1.2 MB -``` - -#### number_to_percentage - -Formats a number as a percentage string. - -```ruby -number_to_percentage(100, precision: 0) # => 100% -``` - -#### number_to_phone - -Formats a number into a phone number (US by default). - -```ruby -number_to_phone(1235551234) # => 123-555-1234 -``` - -#### number_with_delimiter - -Formats a number with grouped thousands using a delimiter. - -```ruby -number_with_delimiter(12345678) # => 12,345,678 -``` - -#### number_with_precision - -Formats a number with the specified level of `precision`, which defaults to 3. - -```ruby -number_with_precision(111.2345) # => 111.235 -number_with_precision(111.2345, precision: 2) # => 111.23 -``` - -### SanitizeHelper - -The SanitizeHelper module provides a set of methods for scrubbing text of undesired HTML elements. - -#### sanitize - -This sanitize helper will HTML encode all tags and strip all attributes that aren't specifically allowed. - -```ruby -sanitize @article.body -``` - -If either the `:attributes` or `:tags` options are passed, only the mentioned attributes and tags are allowed and nothing else. - -```ruby -sanitize @article.body, tags: %w(table tr td), attributes: %w(id class style) -``` - -To change defaults for multiple uses, for example adding table tags to the default: - -```ruby -class Application < Rails::Application - config.action_view.sanitized_allowed_tags = 'table', 'tr', 'td' -end -``` - -#### sanitize_css(style) - -Sanitizes a block of CSS code. - -#### strip_links(html) -Strips all link tags from text leaving just the link text. - -```ruby -strip_links('Ruby on Rails') -# => Ruby on Rails -``` - -```ruby -strip_links('emails to me@email.com.') -# => emails to me@email.com. -``` - -```ruby -strip_links('Blog: Visit.') -# => Blog: Visit. -``` - -#### strip_tags(html) - -Strips all HTML tags from the html, including comments. -This functionality is powered by the rails-html-sanitizer gem. - -```ruby -strip_tags("Strip these tags!") -# => Strip these tags! -``` - -```ruby -strip_tags("Bold no more! See more") -# => Bold no more! See more -``` - -NB: The output may still contain unescaped '<', '>', '&' characters and confuse browsers. - -### UrlHelper - -Provides methods to make links and get URLs that depend on the routing subsystem. - -#### url_for - -Returns the URL for the set of `options` provided. - -##### Examples - -```ruby -url_for @profile -# => /profiles/1 - -url_for [ @hotel, @booking, page: 2, line: 3 ] -# => /hotels/1/bookings/1?line=3&page=2 -``` - -#### link_to - -Links to a URL derived from `url_for` under the hood. Primarily used to -create RESTful resource links, which for this example, boils down to -when passing models to `link_to`. - -**Examples** - -```ruby -link_to "Profile", @profile -# => Profile -``` - -You can use a block as well if your link target can't fit in the name parameter. ERB example: - -```html+erb -<%= link_to @profile do %> - <%= @profile.name %> -- Check it out! -<% end %> -``` - -would output: - -```html - - David -- Check it out! - -``` - -See [the API Doc for more info](https://api.rubyonrails.org/classes/ActionView/Helpers/UrlHelper.html#method-i-link_to) - -#### button_to - -Generates a form that submits to the passed URL. The form has a submit button -with the value of the `name`. - -##### Examples - -```html+erb -<%= button_to "Sign in", sign_in_path %> -``` - -would roughly output something like: - -```html - -``` - -See [the API Doc for more info](https://api.rubyonrails.org/classes/ActionView/Helpers/UrlHelper.html#method-i-button_to) - -### CsrfHelper - -Returns meta tags "csrf-param" and "csrf-token" with the name of the cross-site -request forgery protection parameter and token, respectively. - -```html -<%= csrf_meta_tags %> -``` - -NOTE: Regular forms generate hidden fields so they do not use these tags. More -details can be found in the [Rails Security Guide](security.html#cross-site-request-forgery-csrf). +You can learn more about helpers in the [Action View Helpers +Guide](action_view_helpers.html) and the [Action View Form Helpers +Guide](form_helpers.html). Localized Views --------------- diff --git a/guides/source/documents.yaml b/guides/source/documents.yaml index 5537cf65f0a0e..45d5297ff83a1 100644 --- a/guides/source/documents.yaml +++ b/guides/source/documents.yaml @@ -43,12 +43,17 @@ - name: Action View Overview url: action_view_overview.html - description: This guide provides an introduction to Action View and introduces a few of the more common view helpers. + description: This guide provides an introduction to Action View. work_in_progress: true - name: Layouts and Rendering in Rails url: layouts_and_rendering.html description: This guide covers the basic layout features of Action Controller and Action View, including rendering and redirecting, using content_for blocks, and working with partials. + - + name: Action View Helpers + url: action_view_helpers.html + description: This guide introduces a few of the more common view helpers. + work_in_progress: true - name: Action View Form Helpers url: form_helpers.html