HtmlPage

Inject content into an existing HTML document.

Installation

Add this line to your application's Gemfile:

gem "html_page"

And then execute:

$ bundle install

Or install it yourself as:

$ gem install html_page

Usage

This gem simplifies injecting content into an existing HTML document.

Given an HTML document as a string, HtmlPage::Renderer can inject strings of content into the <head> and <body>:

renderer = HtmlPage::Renderer.new(
  content: "<html><head></head><body></body></html>",
  head: "<title>Appended to the head!</title>",
  body: "<h1>Appended to the body!</h1>",
)

renderer.render #=> "<html><head><title>Appended to the head!</title></head><body><h1>Appended to the body</h1></body></html>"

The gem also includes the HtmlPage::Capture class.

Given a Rails helpers as a context along with a block, the Capture class simplifies appending content captured from a Rails view into the HTML's <head> and <body> tags.

For example, given the render_html_with_modifications defined as:

require "html_page"

module MyRailsHelper
  def render_html_with_modifications(html_page_as_string, &block)
    capturer = HtmlPage::Capture.new(self, &block)

    head, body = capturer.capture

    renderer = HtmlPage::Renderer.new(
      content: html_page_as_string,
      head: head,
      body: body,
    )

    render inline: renderer.render
  end
end

The rendered HTML page will include content captured with from the view:

<%= render_html_with_modifications @html_page_as_string do %>
  <title>
    Without a block argument,
    the contents of the block will be appended to the `head` element
  </title>
<% end %>

<%= render_html_with_modifications @html_page_as_string do |head| %>
  <% head.append do %>
    <title>A single argument, yields the `head`</title>
  <% end %>
<% end %>

<%= render_html_with_modifications @html_page_as_string do |head, body| %>
  <% head.append do %>
    <title>Both the `head` and `body` can be yielded</title>
  <% end %>
<% end %>

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/html_page. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

The gem is available as open source under the terms of the MIT License.