xml = File.read('patient-example.xml')
patient = FHIR.from_contents(xml)
puts patient.to_xml

json = File.read('patient-example.json')
patient = FHIR.from_contents(json)
puts patient.to_json

obs = FHIR::Observation.new(
  'status' => 'final',
  'code' => {
    'coding' => [{ 'system' => 'http://loinc.org', 'code' => '3141-9', 'display' => 'Weight Measured' }],
    'text' => 'Weight Measured'
  },
  'category' => {
    'coding' => [{ 'system' => 'http://hl7.org/fhir/observation-category', 'code' => 'vital-signs' }]
  },
  'subject' => { 'reference' => 'Patient/example' },
  'context' => { 'reference' => 'Encounter/example' }
)
obs.valueQuantity = FHIR::Quantity.new(
  'value' => 185,
  'unit' => 'lbs',
  'code' => '[lb_av]',
  'system' => 'http://unitsofmeasure.org'
)

patient.valid? # returns true or false
patient.validate # returns Hash of errors, empty if valid

sd = FHIR::Definitions.resource_definition('Patient')
sd.validates_resource?(patient) # passing in FHIR::Patient
# Validation failed? Get the errors and warnings...
puts sd.errors
puts sd.warnings