N-P

NAMED TEMPLATE ( XSLT )

An <xsl:template> element in the stylesheet with a name attribute. A named template may be invoked using an <xsl:call-template> instruction.

NAMESPACE (XML NAMESPACES)

A named collection of names . The namespace is named using a URI (or in the 1.1 specification, an IRI), which is intended to be formed in such a way as to ensure global uniqueness, but which, in practice, may be any string. Within a particular region of a document, a namespace is also identified by a shorthand name called a prefix; different prefixes can be used to refer to the same namespace in different documents or even within the same document. A name (of an element or attribute in XML, and of a variable, template, function, mode, and so on in XSLT) belongs to a specific namespace, and two names can be considered equivalent only if they belong to the same namespace.

NAMESPACE AXIS ( XPATH )

The namespace axis selects all the namespace nodes belonging to the context node. If the context node is not an element node, the axis will be empty. For element nodes, there is one namespace node for every namespace that is in scope for the element, whether it relates to a namespace declaration that was defined on this element or on a containing element. This is a forwards axis. The namespace axis is retained in XPath 2.0, but is deprecated: applications requiring namespace information should instead use the functions in-scope-prefixes () and namespace-for-prefix() .

NAMESPACE DECLARATION ( XML NAMESPACES )

A construct in an XML document that declares that within a particular region of the document, a given namespace prefix will be used to refer to the namespace with a particular URI. There are two forms of namespace declaration: xmlns="uri" to declare the default namespace (the one with a null prefix), and xmlns:prefix="uri" to declare a namespace with a non-null prefix. Both are written in the form of XML attributes and apply to the element they are on and all descendant elements, unless overridden.

NAMESPACE FIXUP (XSLT)

Namespace fixup is the process of adding namespace nodes to a newly constructed element node to ensure that all the namespaces actually used by the element are properly declared.

NAMESPACE NODE ( XPATH )

A node in a tree that represents the binding of a namespace prefix to a namespace URI. A namespace node belongs to an element called its parent: it applies only to that element and not to any descendant elements.

NAMESPACE PREFIX (XML NAMESPACES)

A short name used to identify a namespace within a particular region of an XML document, so called because it is most often used as the prefix of a lexical QName (the part before the colon ). Different prefixes can be used to identify the same namespace, and in different contexts the same prefix can be used to identify different namespaces.

NAMESPACE URI ( XML NAMESPACES)

A URI used to identify a namespace. Namespace URIs are unusual in that there is no actual resource that can be obtained using the URI; the URI is simply a unique identifier. In practice, any string can be used as a namespace URI, though «http:// » URLs are often used to give some prospect of uniqueness. Technically, the XML Namespaces specification refers to this concept as a namespace name, and in version 1.1 the namespace name can be an IRI, which unlike a URI allows non-ASCII characters . However, the term namespace URI is in widespread use despite the fact that practical products allow any string to be used.

NAN (XPATH)

Not-a-Number. This is one of the possible values of a variable whose data type is float or double. It results from an operation whose result is not numeric, for example «number('apple') » .

NODE ( XPATH )

An object forming part of a tree. There are seven kinds of node: attribute nodes, comment nodes, document nodes, element nodes, namespace nodes, processing instruction nodes, and text nodes. Nodes have properties including a name, a string value, a typed value, and a base URI. Every kind of node except a document node may have a parent node; document nodes and element nodes may have children; element nodes may have attributes and namespaces.

NODE KIND (XPATH)

Nodes are classified into seven kinds: attribute nodes, comment nodes, document nodes, element nodes, namespace nodes, processing instruction nodes, and text nodes.

NUMBER (XPATH)

In XPath 2.0, the term number is used as a generic term for the three primitive types decimal , double , and float , and their subtypes (including integer ).

OUTPUT METHOD (XSLT)

XSLT 2.0 defines four output methods , xml, html, xhtml, and text. The output method controls the way in which the result tree is output (or serialized ) as a stream of characters or bytes.

PARAMETER ( XSLT )

A variable whose value is supplied by the caller. A stylesheet parameter is a global variable whose value can be set (in a vendor-defined way) when the stylesheet is executed. A template parameter is defined within an <xsl:template> element, and its value can be set when the template is invoked using <xsl:apply-templates> or <xsl:call-template> . A function parameter is defined within an <xsl:function> element, and is set by evaluating the arguments in an XPath function call.

PARENT AXIS ( XPATH )

The parent axis selects the node that is the parent of the context node, assuming it has a parent. Since this axis selects at most one node, it doesn't matter whether it is considered as a forwards axis or as a reverse axis.

PARTICLE (SCHEMA)

In the language of XML Schema, a particle is a component part of the definition of the structure of a complex type. A particle may be an element declaration, or a wildcard that allows elements from defined namespaces, or a sequence or choice compositor with a defined substructure .

PATH EXPRESSION (XPATH)

A path expression is an expression that selects a sequence of nodes in a tree. It defines a sequence of steps that define navigation paths from the context node to further nodes. The final result is the sequence of nodes reached by following each of the steps in turn . For example, the path expression «../@code » has two steps: the first step selects the parent of the context node, and the second step selects the «code » attribute of the selected parent. The nodes in the result of a path expression are always returned in document order, with duplicates removed.

PATTERN ( XSLT )

A construct that defines a condition that a node either satisfies or does not satisfy . The syntax for a pattern is a subset of the syntax for an XPath expression. Patterns are used in only four XSLT elements: <xsl:template> , <xsl:key> , <xsl:number> , and <xsl:for-each- group > .

PRECEDENCE ( XSLT )

See IMPORT PRECEDENCE (XSLT).

PRECEDING AXIS (XPATH)

The preceding axis selects all the nodes that precede the context node within the same tree, with the exception of attribute and namespace nodes, and the node's own ancestors . This is a reverse axis.

PRECEDING SIBLING AXIS (XPATH)

The preceding sibling axis selects all the nodes that precede the context node and that share the same parent node. This is a reverse axis.

PREDICATE (XPATH)

An expression used to filter which nodes are selected by a particular step in a path expression, or to select a subset of the items in a sequence . A boolean expression selects the items for which the predicate is true; a numeric expression selects the item at the position given by the value of the expression, for example «[1] » selects the first item.

PREFIX ( XML NAMESPACES )

See NAMESPACE PREFIX (XML NAMESPACES).

PRIMITIVE TYPE (SCHEMA)

The XML Schema specification defines 19 primitive types. In the XPath model these are defined as subtypes of the abstract type xdt:anyAtomicType , which contains all atomic values. The 19 primitive types are boolean , string , decimal , double , float , QName , anyURI , hexBinary , base64Binary , date , time , dateTime , gYear , gYearMonth , gMonth , gMonthDay , gDay , duration , and NOTATION . XPath in effect adds untypedAtomic to this list, representing values that have not been validated against any schema.

PRINCIPAL NODE KIND (XPATH)

Every axis has a principal node kind. For most axes, the principal node kind is elements. For the attribute axis, the principal node kind is attribute, and for the namespace axis, it is namespace. The principal node kind determines the kind of nodes selected by the node test «* »: for example, «following-siblings::* » selects elements, while «namespace::* » selects namespace nodes.

PRIORITY (XSLT)

Every template rule has a priority. The priority is expressed as a number (which may be a decimal number such as «3.5 » ). The priority may be specified explicitly, using the priority attribute of the <xsl:template> element; if it is omitted a default priority is allocated based on the pattern. The priority is used to decide which template rule to evaluate when several template rules match the same node: a rule with numerically higher priority is used in preference to one with lower priority.

PROCESSING INSTRUCTION (XML)

An item in an XML document that is conventionally used to carry instructions to the software that receives the document and processes it. Written between the delimiters «<? » and «?> » . Note that the XML declaration at the start of a document, and the text declaration at the start of an external parsed entity, are not processing instructions even though they use the same delimiters.

PROCESSING INSTRUCTION NODE (XPATH)

A node in a tree representing an XML processing instruction.

PROMOTION (XPATH)

The type-checking rules for function calling in XPath, and also for arithmetic operators and comparison operators, allow numeric values to be used where a different numeric type is expected. The operation of converting the supplied number to the required type (for example, integer to double) is known as promotion.