Documentation

Overview

    Package xsd parses type declarations in XML Schema documents.

    The xsd package implements a parser for a subset of the XML Schema standard. This package is intended for use in code-generation programs for client libraries, and as such, does not validate XML Schema documents, nor does it provide sufficient information to validate the documents described by a schema. Notably, the xsd package does not preserve information about element or attribute groups. Instead, all groups are de-referenced before parsing is done, and all nested sequences of elements are flattened.

    The xsd package respects XML name spaces in schema documents, and can parse schema documents that import or include other schema documents.

    Index

    Constants

    This section is empty.

    Variables

    View Source
    var StandardSchema = [][]byte{
    	soapenc11xsd,
    	xmlnsxsd,
    	wsdl2003xsd,
    	xlinkxsd,
    }

      The xsd package bundles a number of well-known schemas. These schemas are always added to the list of available schema when parsing an XML schema using the Parse function.

      Functions

      func Normalize

      func Normalize(docs ...[]byte) ([]*xmltree.Element, error)

        Normalize reads XML schema documents and returns xml trees for each schema with the following properties:

        * various XSD shorthand, such as omitting <complexContent>,

        are expanded into their canonical forms.
        

        * all links are dereferenced by merging the linked element. * all types have names. For anonymous types, unique (per

        namespace) names of the form "_anon1", "_anon2", etc are
        generated, and the attribute "_isAnonymous" is set to
        "true".
        

        Because one document may contain more than one schema, the number of trees returned by Normalize may not equal the number of arguments.

        func XMLName

        func XMLName(t Type) xml.Name

          XMLName returns the canonical xml name of a Type.

          Types

          type Attribute

          type Attribute struct {
          	// The canonical name of this attribute. It is uncommon for attributes
          	// to have a name space.
          	Name xml.Name
          	// Annotation provided for this attribute by the schema author.
          	Doc string
          	// The type of the attribute value. Must be a simple or built-in Type.
          	Type Type
          	// True if this attribute has a <list> simpleType
          	Plural bool
          	// Default overrides the zero value of this element.
          	Default string
          	// True if the attribute is not required
          	Optional bool
          	// Any additional attributes provided in the <xs:attribute> element.
          	Attr []xml.Attr
          	// Used for resolving qnames in additional attributes.
          	xmltree.Scope
          }

            An Attribute describes the key=value pairs that may appear within the opening tag of an element. Only complex types may contain attributes. the Type of an Attribute can only be a Builtin or SimpleType.

            http://www.w3.org/TR/2004/REC-xmlschema-1-20041028/structures.html#element-attribute

            type Builtin

            type Builtin int

              A built-in represents one of the built-in xml schema types, as defined in the W3C specification, "XML Schema Part 2: Datatypes".

              http://www.w3.org/TR/xmlschema-2/#built-in-datatypes

              const (
              	AnyType Builtin = iota
              	ENTITIES
              	ENTITY
              	ID
              	IDREF
              	IDREFS
              	NCName
              	NMTOKEN
              	NMTOKENS
              	NOTATION
              	Name
              	QName
              	AnyURI
              	Base64Binary
              	Boolean
              	Byte
              	Date
              	DateTime // ISO 8601 format (similar to RFC3339)
              	Decimal
              	Double
              	Duration
              	Float
              	GDay       // ---DD
              	GMonth     // --MM
              	GMonthDay  // --MM-DD
              	GYear      // YYYY
              	GYearMonth // YYYY-MM
              	HexBinary
              	Int
              	Integer
              	Language
              	Long
              	NegativeInteger
              	NonNegativeInteger
              	NonPositiveInteger
              	NormalizedString
              	PositiveInteger
              	Short
              	String
              	Time
              	Token
              	UnsignedByte
              	UnsignedInt
              	UnsignedLong
              	UnsignedShort
              	XMLLang  // xml:lang
              	XMLSpace // xml:space
              	XMLBase  // xml:base
              	XMLId    // xml:id
              	AnySimpleType
              )

              func ParseBuiltin

              func ParseBuiltin(qname xml.Name) (Builtin, error)

                ParseBuiltin looks up a Builtin by name. If qname does not name a built-in type, ParseBuiltin returns a non-nil error.

                func (Builtin) Name

                func (b Builtin) Name() xml.Name

                  Name returns the canonical name of the built-in type. All built-in types are in the standard XML schema namespace, http://www.w3.org/2001/XMLSchema, or the XML namespace, http://www.w3.org/2009/01/xml.xsd

                  func (Builtin) String

                  func (i Builtin) String() string

                  type ComplexType

                  type ComplexType struct {
                  	// Annotations provided by the schema author.
                  	Doc string
                  	// The canonical name of this type.
                  	Name xml.Name
                  	// The type this type is derived from.
                  	Base Type
                  	// True if this is an anonymous type
                  	Anonymous bool
                  	// XML elements that this type may contain in its content.
                  	Elements []Element
                  	// Possible attributes for the element's opening tag.
                  	Attributes []Attribute
                  	// An abstract type does not appear in the xml document, but
                  	// is "implemented" by other types in its substitution group.
                  	Abstract bool
                  	// If true, this type is an extension to Base.  Otherwise,
                  	// this type is derived by restricting the set of elements and
                  	// attributes allowed in Base.
                  	Extends bool
                  	// If true, this type is allowed to contain character data that is
                  	// not part of any sub-element.
                  	Mixed bool
                  }

                    A ComplexType describes an XML element that may contain attributes and elements in its content. Complex types are derived by extending or restricting another type. The xsd package records the elements and attributes that may occur in an xml element conforming to the type. A ComplexType is part of a linked list, through its Base field, that is guaranteed to end in the Builtin value AnyType.

                    http://www.w3.org/TR/2004/REC-xmlschema-1-20041028/structures.html#element-complexType

                    type Element

                    type Element struct {
                    	// Annotations for this element
                    	Doc string
                    	// The canonical name of this element
                    	Name xml.Name
                    	// True if this element can have any name. See
                    	// http://www.w3.org/TR/2004/REC-xmlschema-1-20041028/structures.html#element-any
                    	Wildcard bool
                    	// Type of this element.
                    	Type Type
                    	// An abstract type does not appear in the xml document, but
                    	// is "implemented" by other types in its substitution group.
                    	Abstract bool
                    	// True if maxOccurs > 1 or maxOccurs == "unbounded"
                    	Plural bool
                    	// True if the element is optional.
                    	Optional bool
                    	// If true, this element will be declared as a pointer.
                    	Nillable bool
                    	// Default overrides the zero value of this element.
                    	Default string
                    	// Any additional attributes provided in the <xs:element> element.
                    	Attr []xml.Attr
                    	// Used for resolving prefixed strings in extra attribute values.
                    	xmltree.Scope
                    }

                      An Element describes an XML element that may appear as part of a complex type. Elements may have restrictions about the number of times they may appear and they values they may contain. The xsd package converts this low-level information into boolean flags where appropriate.

                      http://www.w3.org/TR/2004/REC-xmlschema-1-20041028/structures.html#element-element

                      type Ref

                      type Ref struct {
                      	Namespace, Location string
                      }

                        A Ref contains the canonical namespace of a schema document, and possibly a URI to retrieve the document from. It is not required for XML Schema documents to provide the location of schema that they import; it is expected that all well-known schema namespaces are available to the consumer of a schema beforehand.

                        func Imports

                        func Imports(data []byte) ([]Ref, error)

                          Imports reads an XML document containing one or more <schema> elements and returns a list of canonical XML name spaces that the schema imports or includes, along with a URL for the schema, if provided.

                          type Restriction

                          type Restriction struct {
                          	// The max digits to the right of the decimal point for
                          	// floating-point values.
                          	Precision int
                          	// If len(Enum) > 0, the type must be one of the values contained
                          	// in Enum.
                          	Enum []string
                          	// The minimum and maximum (exclusive) value of this type, if
                          	// numeric
                          	Min, Max float64
                          	// Maximum and minimum length (in characters) of this type
                          	MinLength, MaxLength int
                          	MinDate, MaxDate     time.Time
                          	// Regular expression that values of this type must match
                          	Pattern *regexp.Regexp
                          	// Any annotations for the restriction, if present.
                          	Doc string
                          }

                            A SimpleType can be derived from a built-in or SimpleType by restricting the set of values it may contain. The xsd package only records restrictions that are useful for generating client libraries, and not for validating documents.

                            http://www.w3.org/TR/2004/REC-xmlschema-2-20041028/datatypes.html#element-restriction

                            type Schema

                            type Schema struct {
                            	// The Target namespace of the schema. All types defined in this
                            	// schema will be in this name space.
                            	TargetNS string `xml:"targetNamespace,attr"`
                            	// Types defined in this schema declaration
                            	Types map[xml.Name]Type
                            	// Any annotations declared at the top-level of the schema, separated
                            	// by new lines.
                            	Doc string
                            }

                              A Schema is the decoded form of an XSD <schema> element. It contains a collection of all types declared in the schema. Top-level elements are not recorded in a Schema.

                              func Parse

                              func Parse(docs ...[]byte) ([]Schema, error)

                                Parse reads XML documents containing one or more <schema> elements. The returned slice has one Schema for every <schema> element in the documents. Parse will not fetch schema used in <import> or <include> statements; use the Imports function to find any additional schema documents required for a schema.

                                func (*Schema) FindType

                                func (s *Schema) FindType(name xml.Name) Type

                                  FindType looks for a type by its canonical name. In addition to the types declared in a Schema, FindType will also search through the types that a Schema's top-level types are derived from. FindType will return nil if a type could not be found with the given name.

                                  type SimpleType

                                  type SimpleType struct {
                                  	// True if this is an anonymous type
                                  	Anonymous bool
                                  	// True if this type is a whitespace-delimited list, with
                                  	// items of type Base.
                                  	List bool
                                  	// A simpleType may be described as a union: one of many
                                  	// possible simpleTypes.
                                  	Union []Type
                                  	// Restrictions on this type's values
                                  	Restriction Restriction
                                  	// The canonical name of this type
                                  	Name xml.Name
                                  	// Any annotations for this type, as provided by the schema
                                  	// author.
                                  	Doc string
                                  	// The type this type is derived from. This is guaranteed to be
                                  	// part of a linked list that always ends in a Builtin type.
                                  	Base Type
                                  }

                                    A SimpleType describes an XML element that does not contain elements or attributes. SimpleTypes are suitable for use as attribute values. A SimpleType can be an "atomic" type (int, string, etc), or a list of atomic types, separated by white space. In addition, a SimpleType may be declared as a union; or one of a set of SimpleTypes. A SimpleType is guaranteed to be part of a linked list, through its Base field, that ends in a Builtin value.

                                    http://www.w3.org/TR/2004/REC-xmlschema-2-20041028/datatypes.html#element-simpleType

                                    http://www.w3.org/TR/2004/REC-xmlschema-2-20041028/datatypes.html#element-union

                                    http://www.w3.org/TR/2004/REC-xmlschema-2-20041028/datatypes.html#element-list

                                    type Type

                                    type Type interface {
                                    	// contains filtered or unexported methods
                                    }

                                      Types in XML Schema Documents are derived from one of the built-in types defined by the standard, by restricting or extending the range of values a type may contain. A Type may be one of *SimpleType, *ComplexType, or Builtin.

                                      func Base

                                      func Base(t Type) Type

                                        Base returns the base type that a Type is derived from. If the value is of type Builtin, Base will return nil.