nokogiri_schematron_builder

nokogiri_schematron_builder

Build Schematron XML documents using Nokogiri.

Installation

Add this line to your application's Gemfile:

gem "nokogiri_schematron_builder"

And then execute:

$ bundle

Or install it yourself as:

$ gem install nokogiri_schematron_builder

Usage

Add this line to your application:

require "nokogiri/xml/schematron/schema"

Create the schema using the domain-specific language:

schema = Nokogiri::XML::Schematron::Schema.new(title: "Example schema") do
  ns(prefix: "ex", uri: "http://example.com/ns#")
  pattern(title: "Example pattern") do
    rule(context: "/") do
      assert(test: "count(ex:A) >= 1", message: "element \"ex:A\" is REQUIRED")
    end
    rule(context: "/ex:A") do
      assert(test: "count(ex:B) >= 0", message: "element \"ex:B\" is OPTIONAL")
    end
    rule(context: "/ex:A/ex:B") do
      assert(test: "not(ex:C)", message: "element \"ex:C\" is NOT RECOMMENDED")
    end
  end
end

Or, equivalently:

schema = Nokogiri::XML::Schematron::Schema.new(title: "Example schema") do
  ns(prefix: "ex", uri: "http://example.com/ns#")
  pattern(title: "Example pattern") do
    context("/") do
      require("ex:A") do
        permit("ex:B") do
          reject("ex:C")
        end
      end
    end
  end
end

Next, construct a Nokogiri::XML::Builder object:

builder = schema.to_builder(encoding: "UTF-8")

Finally, generate the XML:

xml = builder.to_xml

The result is:

<?xml version="1.0" encoding="UTF-8"?>
<sch:schema xmlns:sch="http://purl.oclc.org/dsdl/schematron">
  <sch:title>Example schema</sch:title>
  <sch:ns prefix="ex" uri="http://example.com/ns#"/>
  <sch:pattern>
    <sch:title>Example pattern</sch:title>
    <sch:rule context="/">
      <sch:assert test="count(ex:A) &gt;= 1">element "ex:A" is REQUIRED</sch:assert>
    </sch:rule>
    <sch:rule context="/ex:A">
      <sch:assert test="count(ex:B) &gt;= 0">element "ex:B" is OPTIONAL</sch:assert>
    </sch:rule>
    <sch:rule context="/ex:A/ex:B">
      <sch:assert test="not(ex:C)">element "ex:C" is NOT RECOMMENDED</sch:assert>
    </sch:rule>
  </sch:pattern>
</sch:schema>

Development

After checking out the repo, run bin/setup to install dependencies. 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.

License

The 2-Clause BSD License

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/pnnl/nokogiri_schematron_builder.