namespace rng = "http://relaxng.org/ns/structure/1.0"
datatypes xsd = "http://www.w3.org/2001/XMLSchema-datatypes"
namespace xml = "http://www.w3.org/XML/1998/namespace"
namespace dsrl = "http://purl.oclc.org/dsdl/dsrl"
default namespace = "http://example.org/ns/dml"

start = element-dml

element-dml = element dml { 
   dmlVersionAttribute? &
   dml-contents
}

dmlVersionAttribute = attribute dmlVersion { "1.0" }

dml-contents = (
   dataModelVersion &
   organization* &   
   contact-info* &   
   list-order* &
   data-category* &
   mustUse-flag* &
   container-existence* &   
   manual-validation* &
   units* &
   conformStatus* &
   mustUnderstand*
)

# Each data model needs a version string
dataModelVersion = element version { xsd:string }

# Information about the data model author(s).
# Seems like this should be in Dublin Core
organization = element organization { string-with-lang }
contact-info = element contact { xsd:anyURI } 

# Processing annotations
unique = element unique { xsd:anyURI } 
key = element key { xsd:anyURI }
keyref = element keyref { xsd:anyURI }

data-category = element infoType { 
   attribute minAccess { list { access-strings }}?,
   attribute maxAccess { list { access-strings }}?,
   ("config" | "status" | "statistics" | "action" | "notify")
   >> dsrl:default-content ["config"]
}
access-strings = ( "read" | "write" | "create" | "delete" | "execute" )

mustUse-flag = element mustUse { xsd:boolean  
               >> dsrl:default-content ["false"]
}

manual-validation = element manual-validation-rule { string-with-lang }

# Semantic hints
list-order = element order { 
  ("any-order" | "user-order")
  >> dsrl:default-content ["any-order"]
}

container-existence = element existence { empty }

units = element units { 
  xsd:string { pattern="[^: \n\r\t]+" } 
  # allow familiar units, but no whitespace or absolute URIs here
  |
  xsd:anyURI { pattern="([a-zA-Z][a-zA-Z0-9\-\+\.]*:|\.\./|\./|#).*" }
  # allow absolute URIs, plus relative URIs with ./ or ../
  # prohibit relative URIs that could look like a unit, ex: m/s
} 
# Definition copied from definition of gml:Uomidentifier from 
# Section 8.2.3.6 of Geography Markup Language (GML) v3.2.1

string-with-lang = (
   attribute xml:lang { xsd:language },
   xsd:string
)

conformStatus = element status { 
   "active" | "deprecated" | "obsolete"
   >> dsrl:default-content ["active"]   
}

# the mustUnderstand element contains space separated list of namespace
# tokens that need to be supported to correctly process the data model
mustUnderstand = element mustUnderstand { list { xsd:NCName } }

dml-netconf-error-app-tag = 
   attribute netconf-error-app-tag { xsd:string }

dml-phase-attribute = attribute phase { "fragment" | "std" | "full" }

dml-moduleDefault = attribute moduleDefault {
  xsd:boolean >> dsrl:default-content ["false"]
}