# From: http://atompub.org/2005/04/18/atom.rnc 2005-04-21 # -*- rnc -*- # RELAX NG Compact Syntax Grammar for the # Atom Format Specification Version 08 namespace atom = "http://purl.org/atom/ns#draft-ietf-atompub-format-08" namespace xhtml = "http://www.w3.org/1999/xhtml" namespace s = "http://www.ascc.net/xml/schematron" start = atomFeed | atomEntry # Common attributes atomCommonAttributes = attribute xml:base { atomUri }?, attribute xml:lang { atomLanguageTag }? # Text Constructs atomPlainTextConstruct = atomCommonAttributes, attribute type { "text" | "html" }?, text atomXHTMLTextConstruct = atomCommonAttributes, attribute type { "xhtml" }, xhtmlDiv atomTextConstruct = atomPlainTextConstruct | atomXHTMLTextConstruct # Person Construct atomPersonConstruct = atomCommonAttributes, (element atom:name { text } & element atom:uri { atomUri }? & element atom:email { atomEmailAddress }? & extensionElement*) # Date Construct atomDateConstruct = atomCommonAttributes, xsd:dateTime # atom:feed atomFeed = [ s:rule [ context = "atom:feed" s:assert [ test = "atom:link[@rel='alternate'] " ~ "or atom:link[not(@rel)]" "An atom:feed must have at least one link element " ~ "with a rel attribute of 'alternate'." ] ] s:rule [ context = "atom:feed" s:assert [ test = "atom:author or not(atom:entry[not(atom:author)])" "An atom:feed must have an atom:author unless all " ~ "of its atom:entry children have an atom:author." ] ] ] element atom:feed { atomCommonAttributes, (atomAuthor? & atomCategory* & atomContributor* & atomCopyright? & atomGenerator? & atomIcon? & atomId? & atomImage? & atomLink+ & atomSubtitle? & atomTitle & atomUpdated & extensionElement*), atomEntry* } # atom:entry atomEntry = [ s:rule [ context = "atom:entry" s:assert [ test = "atom:link[@rel='alternate'] " ~ "or atom:link[not(@rel)] " ~ "or atom:content" "An atom:entry must have at least one link element " ~ "with a rel attribute of 'alternate' or content." ] ] s:rule [ context = "atom:entry" s:assert [ test = "atom:author or " ~ "../atom:author or atom:source/atom:author" "An atom:entry must have an atom:author " ~ "if its feed does not." ] ] # N.B. This rule doesn't test # for content with a non-binary type. s:rule [ context = "atom:entry" s:assert [ test = "atom:summary or atom:content[not(@src)]" "An atom:entry must have an atom:summary " ~ "if the atom:content element is empty." ] ] ] element atom:entry { atomCommonAttributes, (atomAuthor? & atomCategory* & atomContent? & atomContributor* & atomCopyright? & atomId & atomLink* & atomPublished? & atomSource? & atomSummary? & atomTitle & atomUpdated & extensionElement*) } # atom:content atomInlineTextContent = element atom:content { atomCommonAttributes, attribute type { "text" | "html" }?, (text)* } atomInlineXHTMLContent = element atom:content { atomCommonAttributes, attribute type { "xhtml" }, xhtmlDiv } atomInlineOtherContent = element atom:content { atomCommonAttributes, attribute type { atomMediaType }?, (text|anyForeignElement)* } atomOutOfLineContent = element atom:content { atomCommonAttributes, attribute type { atomMediaType }?, attribute src { atomUri }, empty } atomContent = atomInlineTextContent | atomInlineXHTMLContent | atomInlineOtherContent | atomOutOfLineContent # atom:author atomAuthor = element atom:author { atomPersonConstruct } # atom:category atomCategory = element atom:category { atomCommonAttributes, attribute term { text }, attribute scheme { atomUri }?, attribute label { text }?, empty } # atom:contributor atomContributor = element atom:contributor { atomPersonConstruct } # atom:copyright atomCopyright = element atom:copyright { atomTextConstruct } # atom:generator atomGenerator = element atom:generator { atomCommonAttributes, attribute uri { atomUri }?, attribute version { text }?, text } # atom:icon atomIcon = element atom:icon { atomCommonAttributes, (atomUri) } # atom:id atomId = element atom:id { atomCommonAttributes, (atomUri) } # atom:image atomImage = element atom:image { atomCommonAttributes, (atomUri) } # atom:link atomLink = element atom:link { atomCommonAttributes, attribute href { atomUri }, attribute rel { atomNCName | atomUri }?, attribute type { atomMediaType }?, attribute hreflang { atomLanguageTag }?, attribute title { text }?, attribute length { text }?, empty } # atom:published atomPublished = element atom:published { atomDateConstruct } # atom:source atomSource = element atom:source { atomCommonAttributes, (atomAuthor? & atomCategory* & atomContributor* & atomCopyright? & atomGenerator? & atomIcon? & atomId? & atomImage? & atomLink+ & atomSubtitle? & atomTitle & atomUpdated & extensionElement*) } # atom:subtitle atomSubtitle = element atom:subtitle { atomTextConstruct } # atom:summary atomSummary = element atom:summary { atomTextConstruct } # atom:title atomTitle = element atom:title { atomTextConstruct } # atom:updated atomUpdated = element atom:updated { atomDateConstruct } # Low-level simple types atomNCName = xsd:string { minLength = "1" pattern = "[^:]*" } # Whatever a media type is, it contains at least one slash atomMediaType = xsd:string { pattern = ".+/.+" } # As defined in RFC 3066 atomLanguageTag = xsd:string { pattern = "[A-Za-z]{1,8}(-[A-Za-z0-9]{1,8})*" } # Unconstrained; it's not entirely clear how IRI fit into # xsd:anyURI so let's not try to constrain it here atomUri = text # Whatever an email address is, it contains at least one @ atomEmailAddress = xsd:string { pattern = ".+@.+" } # Simple Extension simpleExtensionElement = element * - atom:* { text } # Structured Extension structuredExtensionElement = element * - atom:* { (attribute * { text }+, (text|anyElement)*) | (attribute * { text }*, (text?, anyElement+, (text|anyElement)*)) } # Other Extensibility extensionElement = simpleExtensionElement | structuredExtensionElement anyElement = element * { (attribute * { text } | text | anyElement)* } anyForeignElement = element * - atom:* { (attribute * { text } | text | anyElement)* } # XHTML anyXHTML = element xhtml:* { (attribute * { text } | text | anyXHTML)* } xhtmlDiv = element xhtml:div { (attribute * { text } | text | anyXHTML)* } # EOF