sigel.xpath.core — me.flowthing/sigel 0.2.2

Functions for selecting and matching things in an XML file with XPath.

For examples, see the function-specific documentation for each function. The examples assume you've required this namespace:

(require '[sigel.xpath.core :as xpath])

Every function in the sigel.xpath.core namespace that select or match things in an XML document rely on an XPathCompiler.

If you don't pass in your own XPathCompiler as the first argument to a function like that, they use *compiler*.

Use variables in XPath expression or pattern

If you need to use variables in your XPath expression or pattern, you can pass a map of variables as the last argument to your XPath operation.

The map key must implement the QNameable protocol. The value must implement the XMLValue protocol.

If you use variables, you also need to pass in an XPathCompiler as the first argument, because setting a variable mutates the XPathCompiler instance.

Example:

(def my-compiler (xpath/compiler))

(xpath/is? my-compiler "<num>1</num>" "xs:integer(num) * $two eq 2" {:two 2})

*compiler* clj

A default XPath compiler.

If you don't pass in your own XPathCompiler instance when compiling a stylesheet, Sigel uses this instance.

->seq clj

(->seq node)

Return a seq on the nodes in the given document.

compiler clj

(compiler)

(compiler processor default-namespace-uri namespaces)

Make a new XPathCompiler.

Optionally, give the default namespace and additional namespace declarations you want the XPathCompiler to know about.

declare-namespace! clj

(declare-namespace! compiler ns-decl)

(declare-namespace! compiler prefix uri)

Teach an XPathCompiler about a namespace.

You can give the namespace either as a string prefix and a string URI or as a Namespace record.

declare-variables! clj

(declare-variables! compiler variables)

Declare variables on an XPathCompiler.

This function does not set the value of a variable. Rather, it tells the XPathCompiler that the value of a variable will be set later.

default-namespace clj

(default-namespace compiler)

Get the default namespace URI of an XPathCompiler.

early-evaluation-context clj

(early-evaluation-context static-context)

Make a new XPath evaluation context from a static context.

is? clj

(is? context expression)

(is? compiler context expression bindings)

Given an XML context and an XPath expression, return a boolean that indicates whether the expression evaluates to true in that context.

Optionally, give a map of XPath variable bindings.

Example:

(xpath/is? compiler "<one>1</one>" "xs:int(one) + 2 eq 3")
; => true

match clj

(match context pattern)

(match compiler context pattern bindings)

Return a sequence of values that match an XPath pattern in the given XML context.

Optionally, give a map of XPath variable bindings.

Example:

(vec (xpath/match "<nums><num>1</num><num>2</num><num>3</num></nums>"
                  "num[xs:int(.) lt 3]"))
;;=>
;;[#object[net.sf.saxon.s9api.XdmNode 0x51912c8 "<num>1</num>"]
;; #object[net.sf.saxon.s9api.XdmNode 0x4cc3057a "<num>2</num>"]]

matches? clj

(matches? node pattern)

(matches? compiler node pattern bindings)

Check whether a node matches a XPath pattern (compiled with pattern).

ns clj

(ns prefix uri)

Create a Namespace record composed of a string prefix and a string URI.

package-data clj

(package-data static-context)

Get the package data of a StaticContext.

pattern clj

(pattern string)

(pattern compiler string)

Make an XPath pattern from a string.

select clj

(select context expression)

(select compiler context expression bindings)

Return a sequence of values that match an XPath expression in the given XML context.

Example:

(def document "<a><b/><c/></a>")

(xpath/select document "a/b | a/c")

;;=> #object[net.sf.saxon.s9api.XdmValue 0x157cb3cd "<b/>\\n<c/>"]

;; `select` returns an XdmValue, which is an Iterable, so you can use
;; Clojure's seq functions on the result.
(str (.getNodeName (first (xpath/select document "a/b | a/c"))))
;;=> "b"

set-default-namespace! clj

(set-default-namespace! compiler uri)

Set the default namespace URI of an XPathCompiler.

Setting the default namespace URI allows you to omit the namespace prefix from your XPath expressions.

Example:

(def my-compiler (xpath/compiler))

(set-default-namespace! my-compiler "bar")

(xpath/select my-compiler "<foo xmlns=\"bar\"><baz/></foo>" "foo/baz")
;;=> #object[net.sf.saxon.s9api.XdmNode 0x2e91fb2b "<baz xmlns=\"bar\"/>"]

set-variable clj

(set-variable selector [name value])

Set a variable on an XPathSelector.

The name of the variable must implement the [[saxon/QNameable]] protocol.

The value of the variable must implement the [[saxon/XmlValue]] protocol.

static-context clj

(static-context compiler)

Get the static context of an XPathCompiler.

value-of clj

(value-of context expression)

(value-of compiler context expression bindings)

Return the value of an XPath expression evaluated in the given context.

If the value is an atomic value, return the value as a Java object of the equivalent type. If it's a node, get the string value of the node.

Example:

(xpath/value-of "<num>1</num>" "xs:int(num)")
;;=> 1