Representative View

"Representative View" integrates Representative as a Rails template format, making it possible to generate XML and JSON representations of data using the same template.

Installing it

Simply add the 'representative_view' gem to your Gemfile

gem "representative_view"

and run "bundle install".

Using it

In your controller, declare that you can provide both XML and JSON, e.g.

class BooksController < ApplicationController

  def index
    respond_to do |format|
      format.xml
      format.json
    end
  end

end

Next, create a template with the suffix ".rep" (to select the Representative View template handler) and use the Representative DSL to generate elements and lists, e.g.

# app/views/books/index.rep

r.list_of :books, @books do
  r.element :title
  r.list_of :authors
end

Note that it's "index.rep", not "index.xml.rep" or "index.json.rep"; those will work, too, but by omitting the format specifier, the same template can be used to render both formats.

Partials

Representative View happily supports the use of partials, as long as they're also in Representative format. Because Representative keeps track of the current "subject" as it renders, there's no need to explicitly pass an object into the partial:

# app/views/books/index.rep

r.list_of :books, @books do
  render :partial => 'book'
end

# app/views/books/_book.rep

r.element :title
r.element :published do
  r.element :by
end

Forcing a format

It can occasionally be useful to include a ".rep" partial from within a non-Representative template, for instance to generate a sample JSON or XML representation in HTML-based API documentation. This is possible by forcing a format using the representative helper-method, as follows:

# app/views/doc/things.html.erb

<h2>Sample JSON output</h2>

<pre>
<%= representative(:json) { render :partial => 'sample_things' } %>
</pre>

# app/views/doc/_sample_things.rep

r.list_of :things, SampleThings.all do
  r.element :name
  r.element :description
end

Configuration

Output can be controlled somewhat setting json_options or xml_options on the RepresentativeView module; these options will be passed when initialising the appropriate Representative::Nokogiri or Representative::JSON object.

For example, setting:

RepresentativeView.json_options = {:naming_strategy => :camelCase}

causes JSON to be output with camelCase (rather than snake_case) labels.