truncate_html is a Rails helper plugin that cuts off a string of HTML and takes care of closing any lingering open tags. There are many possible solutions to this. This plugin does not have any dependencies, and does all it's work via regular expressions.
The API is very similar to Rails' own truncate() method.
some_html = '<ul><li><a href="http://whatever">This is a link</a></li></ul>'
truncate_html(some_html, :length => 15, :omission => '...(continued)')
=> <ul><li><a href="http://whatever">This...(continued)</a></li></ul>A few notes:
-
By default, it will truncate on word boundary. To truncate the HTML string strictly at the specified length, pass in the
:word_boundary => falseoption. -
If the input HTML is nil, it will return an empty string.
-
The omission text's length does count toward the resulting string's length.
-
<script>tags will pass right through - they will not count toward the resulting string's length, or be truncated. -
The default options are:
:length: 100:omission: '...':word_boundary: /\S/
You may also set global configuration options.
For example, place the following on application boot,
something like config/initializers/truncate_html.rb
TruncateHtml.configure do |config|
config.length = 50
config.omission = '...(continued)'
endIf you really want, you can even set a custom word boundary regexp. For example, to truncate at the end of the nearest sentence:
TruncateHtml.configure do |config|
config.word_boundary = /\S[\.\?\!]/
endYou can also truncate the html at a specific point not based on length but content.
To do that, place the :break_token in your source. This allows the truncation to be
data driven, breaking after a leading paragraph or sentence. If the
:break_token is in your content before the specified :length, :length will be
ignored and the content truncated at :break_token
If the :break_token is in your content after the specified :length,
:break_token will be ignored and the content truncated at :length
TruncateHtml.configure do |config|
config.break_token = '<!-- truncate -->'
endThe latest gem version for the Rails 2.x series is 0.3.2. To use truncate_html on a Rails 2 app, please install the 0.3.2 version:
gem install truncate_html -v 0.3.2
For Rails 3, use the latest truncate_html:
gem install truncate_html
Found an issue or have a suggestion? Please report it on Github's issue tracker.
bundle
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All green? Go hack.
Copyright (c) 2009 - 2010 Harold A. Giménez, released under the MIT license
Thanks to all the contributors!

