[Ruby on Rails] テキストフォーマット関連の便利なViewヘルパー

Module: ActionView::Helpers::TextHelper
(http://api.rubyonrails.com)

auto_link(text, link = :all, href_options = {}, &block)

テキストに含まれるURLとメールアドレスをAタグで囲えるメソッド。

パラメーター

text:

置き換えたいURLやメールアドレスが含まれるテクスト

link:

:all(default), :email_addresses, :urlsの３つから選べる。:allはURLとメールアドレスをすべて変換。

href_options:

属性をハッシュで指定できる。{:target => '_blank'}など。

&block:

置き換えの対象のURLやメールアドレスをブロックで処理できる。

auto_link("Go to http://www.rubyonrails.org and say hello to david@loudthinking.com")
# => "Go to <a href=\"http://www.rubyonrails.org\">http://www.rubyonrails.org</a> and
#     say hello to <a href=\"mailto:david@loudthinking.com\">david@loudthinking.com</a>"

auto_link("Visit http://www.loudthinking.com/ or e-mail david@loudthinking.com", :urls)
# => "Visit <a href=\"http://www.loudthinking.com/\">http://www.loudthinking.com/</a>
#     or e-mail david@loudthinking.com"

auto_link("Visit http://www.loudthinking.com/ or e-mail david@loudthinking.com", :email_addresses)
# => "Visit http://www.loudthinking.com/ or e-mail <a href=\"mailto:david@loudthinking.com\">david@loudthinking.com</a>"

post_body = "Welcome to my new blog at http://www.myblog.com/.  Please e-mail me at me@email.com."
auto_link(post_body, :all, :target => '_blank') do |text|
  truncate(text, 15)
end
# => "Welcome to my new blog at <a href=\"http://www.myblog.com/\" target=\"_blank\">http://www.m...</a>.
      Please e-mail me at <a href=\"mailto:me@email.com\">me@email.com</a>."

simple_format(text)

シンプルなルールで改行をフォーマットできるメソッド
２つ以上の連続する改行コード(\n\n) => pタグ
ひとつの改行コード(\n) => brタグ

my_text = """Here is some basic text...
          ...with a line break."""

simple_format(my_text)
# => "<p>Here is some basic text...<br />...with a line break.</p>"

more_text = """We want to put a paragraph...

            ...right there."""

simple_format(more_text)
# => "<p>We want to put a paragraph...</p><p>...right there.</p>"

Pタグがうるさく感じるようなら独自ヘルパーで対応。改行コードをbrタグに置き換え。
application_helper.rb

module ApplicationHelper
  def linebreaksbr(text)
    return text.gsub(/\r\n|\r|\n/, "<br />")
  end
end

textilize(text)

Textile記法をHTMLに変換できるメソッド。
Textileのシンタックスについて詳しくはこちら。
このメソッドを使用するにはRedClothモジュールが必要なので注意。

textilize("*This is Textile!*  Rejoice!")
# => "<p><strong>This is Textile!</strong>  Rejoice!</p>"

textilize("I _love_ ROR(Ruby on Rails)!")
# => "<p>I <em>love</em> <acronym title="Ruby on Rails">ROR</acronym>!</p>"

textilize("h2. Textile makes markup -easy- simple!")
# => "<h2>Textile makes markup <del>easy</del> simple!</h2>"

textilize("Visit the Rails website "here":http://www.rubyonrails.org/.)
# => "<p>Visit the Rails website <a href="http://www.rubyonrails.org/">here</a>.</p>"

textilize_without_paragraph(text)

textilizeとほとんど同じだけど、こちらはPタグを付加しない。


truncate(text, length = 30, truncate_string = "...")

テキストをX文字以内に切り詰めるメソッド。

truncate("Once upon a time in a world far far away", 14)
# => Once upon a...

truncate("Once upon a time in a world far far away")
# => Once upon a time in a world f...

truncate("And they found that many people were sleeping better.", 25, "(clipped)")
# => And they found that many (clipped)

truncate("And they found that many people were sleeping better.", 15, "... (continued)")
# => And they found... (continued)