Golang xml.Node类代码示例

func CompileSingleNode(node xml.Node) (step CompiledStep) {
	switch node.NodeType() {
	case xml.XML_ELEMENT_NODE:
		ns := node.Namespace()
		// element, extension namespace = extension
		if ns == XSLT_NAMESPACE {
			// element, XSLT namespace = instruction
			switch node.Name() {
			case "variable":
				step = &Variable{Node: node}
			case "param", "with-param":
				step = &Variable{Node: node}
			default:
				step = &XsltInstruction{Name: node.Name(), Node: node}
			}
		} else {
			// element other namespace = LRE
			step = &LiteralResultElement{Node: node}
		}
	// text, CDATA node
	case xml.XML_TEXT_NODE, xml.XML_CDATA_SECTION_NODE:
		if !IsBlank(node) {
			step = &TextOutput{Content: node.Content()}
		}
	}
	return
}

func (style *Stylesheet) populateKeys(node xml.Node, context *ExecutionContext) {
	for _, key := range style.Keys {
		//see if the current node matches
		matches := CompileMatch(key.match, nil)
		hasMatch := false
		for _, m := range matches {
			if m.EvalMatch(node, "", context) {
				hasMatch = true
				break
			}
		}
		if !hasMatch {
			continue
		}
		lookupkey, _ := node.EvalXPath(key.use, context)
		lookup := ""
		switch lk := lookupkey.(type) {
		case []xml.Node:
			if len(lk) == 0 {
				continue
			}
			lookup = lk[0].String()
		case string:
			lookup = lk
		default:
			lookup = fmt.Sprintf("%v", lk)
		}
		key.nodes[lookup] = append(key.nodes[lookup], node)
	}
	children := context.ChildrenOf(node)
	for _, cur := range children {
		style.populateKeys(cur, context)
	}
}

func (e *LiteralResultElement) Compile(node xml.Node) {
	for cur := node.FirstChild(); cur != nil; cur = cur.NextSibling() {
		res := CompileSingleNode(cur)
		if res != nil {
			res.Compile(cur)
			e.Children = append(e.Children, res)
		}
	}
}

func (template *Template) CompileContent(node xml.Node) {
	//parse the content and register the match pattern
	for cur := node.FirstChild(); cur != nil; cur = cur.NextSibling() {
		res := CompileSingleNode(cur)
		if res != nil {
			res.Compile(cur)
			template.AddChild(res)
		}
	}
}

// Determine the default namespace currently defined in scope
func (context *ExecutionContext) DefaultNamespace(node xml.Node) string {
	//get the list of in-scope namespaces
	// any with a null prefix? return that
	decl := node.DeclaredNamespaces()
	for _, d := range decl {
		if d.Prefix == "" {
			return d.Uri
		}
	}
	return ""
}

// ChildrenOf returns the node children, ignoring any whitespace-only text nodes that
// are stripped by strip-space or xml:space
func (context *ExecutionContext) ChildrenOf(node xml.Node) (children []xml.Node) {

	for cur := node.FirstChild(); cur != nil; cur = cur.NextSibling() {
		//don't count stripped nodes
		if context.ShouldStrip(cur) {
			continue
		}
		children = append(children, cur)
	}
	return
}

// Compile the instruction.
//
// TODO: we should validate the structure during this step
func (i *XsltInstruction) Compile(node xml.Node) {
	for cur := node.FirstChild(); cur != nil; cur = cur.NextSibling() {
		res := CompileSingleNode(cur)
		if cur.Name() == "sort" && cur.Namespace() == XSLT_NAMESPACE {
			i.sorting = append(i.sorting, compileSortFunction(res.(*XsltInstruction)))
			continue
		}
		if res != nil {
			res.Compile(cur)
			i.Children = append(i.Children, res)
		}
	}
}

// Propogate namespaces to the root of the output document
func (context *ExecutionContext) DeclareStylesheetNamespacesIfRoot(node xml.Node) {
	if context.OutputNode.NodeType() != xml.XML_DOCUMENT_NODE {
		return
	}
	//add all namespace declarations to r
	for uri, prefix := range context.Style.NamespaceMapping {
		if uri != XSLT_NAMESPACE {
			//these don't actually change if there is no alias
			_, uri = ResolveAlias(context.Style, prefix, uri)
			if !context.Style.IsExcluded(prefix) {
				node.DeclareNamespace(prefix, uri)
			}
		}
	}
}

func (context *ExecutionContext) EvalXPathAsNodeset(xmlNode xml.Node, data interface{}) (result xml.Nodeset, err error) {
	_, err = context.EvalXPath(xmlNode, data)
	if err != nil {
		return nil, err
	}
	nodePtrs, err := context.XPathContext.ResultAsNodeset()
	if err != nil {
		return nil, err
	}
	var output xml.Nodeset
	for _, nodePtr := range nodePtrs {
		output = append(output, xml.NewNode(nodePtr, xmlNode.MyDocument()))
	}
	result = output
	return
}

func (context *ExecutionContext) EvalXPath(xmlNode xml.Node, data interface{}) (result interface{}, err error) {
	switch data := data.(type) {
	case string:
		if xpathExpr := xpath.Compile(data); xpathExpr != nil {
			defer xpathExpr.Free()
			result, err = context.EvalXPath(xmlNode, xpathExpr)
		} else {
			err = errors.New("cannot compile xpath: " + data)
		}
	case []byte:
		result, err = context.EvalXPath(xmlNode, string(data))
	case *xpath.Expression:
		xpathCtx := context.XPathContext
		xpathCtx.SetResolver(context)
		err := xpathCtx.Evaluate(xmlNode.NodePtr(), data)
		if err != nil {
			return nil, err
		}
		rt := xpathCtx.ReturnType()
		switch rt {
		case xpath.XPATH_NODESET, xpath.XPATH_XSLT_TREE:
			nodePtrs, err := xpathCtx.ResultAsNodeset()
			if err != nil {
				return nil, err
			}
			var output []xml.Node
			for _, nodePtr := range nodePtrs {
				output = append(output, xml.NewNode(nodePtr, xmlNode.MyDocument()))
			}
			result = output
		case xpath.XPATH_NUMBER:
			result, err = xpathCtx.ResultAsNumber()
		case xpath.XPATH_BOOLEAN:
			result, err = xpathCtx.ResultAsBoolean()
		default:
			result, err = xpathCtx.ResultAsString()
		}
	default:
		err = errors.New("Strange type passed to ExecutionContext.EvalXPath")
	}
	return
}

// ShouldStrip evaluates the strip-space, preserve-space, and xml:space rules
// and returns true if a node is a whitespace-only text node that should
// be stripped.
func (context *ExecutionContext) ShouldStrip(xmlNode xml.Node) bool {
	if xmlNode.NodeType() != xml.XML_TEXT_NODE {
		return false
	}
	if !IsBlank(xmlNode) {
		return false
	}
	//do we have a match in strip-space?
	elem := xmlNode.Parent().Name()
	ns := xmlNode.Parent().Namespace()
	for _, pat := range context.Style.StripSpace {
		if pat == elem {
			return true
		}
		if pat == "*" {
			return true
		}
		if strings.Contains(pat, ":") {
			uri, name := context.ResolveQName(pat)
			if uri == ns {
				if name == elem || name == "*" {
					return true
				}
			}
		}
	}
	//do we have a match in preserve-space?
	//resolve conflicts by priority (QName, ns:*, *)
	//return a value
	return false
}

// Returns true if the node is a whitespace-only text node
func IsBlank(xmlnode xml.Node) bool {
	if xmlnode.NodeType() == xml.XML_TEXT_NODE || xmlnode.NodeType() == xml.XML_CDATA_SECTION_NODE {
		content := xmlnode.Content()
		if content == "" || strings.TrimSpace(content) == "" {
			return true
		}
	}
	return false
}

func (context *ExecutionContext) UseCDataSection(node xml.Node) bool {
	if node.NodeType() != xml.XML_ELEMENT_NODE {
		return false
	}
	name := node.Name()
	ns := node.Namespace()
	for _, el := range context.Style.CDataElements {
		if el == name {
			return true
		}
		uri, elname := context.ResolveQName(el)
		if uri == ns && name == elname {
			return true
		}
	}
	return false
}

// ParseTemplate parses and compiles the xsl:template elements.
func (style *Stylesheet) ParseTemplate(node xml.Node) {
	//add to template list of stylesheet
	//parse mode, match, name, priority
	mode := node.Attr("mode")
	name := node.Attr("name")
	match := node.Attr("match")
	priority := node.Attr("priority")
	p := 0.0
	if priority != "" {
		p, _ = strconv.ParseFloat(priority, 64)
	}

	// TODO: validate the name (duplicate should raise error)
	template := &Template{Match: match, Mode: mode, Name: name, Priority: p, Node: node}

	template.CompileContent(node)

	//  compile pattern
	style.compilePattern(template, priority)
}

func (style *Stylesheet) processDefaultRule(node xml.Node, context *ExecutionContext) {
	//default for DOCUMENT, ELEMENT
	children := context.ChildrenOf(node)
	total := len(children)
	for i, cur := range children {
		context.XPathContext.SetContextPosition(i+1, total)
		style.processNode(cur, context, nil)
	}
	//default for CDATA, TEXT, ATTR is copy as text
	if node.NodeType() == xml.XML_TEXT_NODE {
		if context.ShouldStrip(node) {
			return
		}
		if context.UseCDataSection(context.OutputNode) {
			r := context.Output.CreateCDataNode(node.Content())
			context.OutputNode.AddChild(r)
		} else {
			r := context.Output.CreateTextNode(node.Content())
			context.OutputNode.AddChild(r)
		}
	}
	//default for namespace declaration is copy to output document
}