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
}
// 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
}
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
}
// Evaluate an instruction and generate output nodes
func (i *XsltInstruction) Apply(node xml.Node, context *ExecutionContext) {
//push context if children to apply!
switch i.Name {
case "apply-templates":
scope := i.Node.Attr("select")
mode := i.Node.Attr("mode")
// #current is a 2.0 keyword
if mode != context.Mode && mode != "#current" {
context.Mode = mode
}
// TODO: determine with-params at compile time
var params []*Variable
for _, cur := range i.Children {
switch p := cur.(type) {
case *Variable:
if IsXsltName(p.Node, "with-param") {
p.Apply(node, context)
params = append(params, p)
}
}
}
// By default, scope is children of current node
if scope == "" {
children := context.ChildrenOf(node)
if i.sorting != nil {
i.Sort(children, context)
}
total := len(children)
oldpos, oldtotal := context.XPathContext.GetContextPosition()
oldcurr := context.Current
for i, cur := range children {
context.XPathContext.SetContextPosition(i+1, total)
//processNode will update Context.Current whenever a template is invoked
context.Style.processNode(cur, context, params)
}
context.XPathContext.SetContextPosition(oldpos, oldtotal)
context.Current = oldcurr
return
}
context.RegisterXPathNamespaces(i.Node)
e := xpath.Compile(scope)
// TODO: ensure we apply strip-space if required
nodes, err := context.EvalXPathAsNodeset(node, e)
if err != nil {
fmt.Println("apply-templates @select", err)
}
if i.sorting != nil {
i.Sort(nodes, context)
}
total := len(nodes)
oldpos, oldtotal := context.XPathContext.GetContextPosition()
oldcurr := context.Current
for i, cur := range nodes {
context.XPathContext.SetContextPosition(i+1, total)
context.Style.processNode(cur, context, params)
}
context.XPathContext.SetContextPosition(oldpos, oldtotal)
context.Current = oldcurr
case "number":
i.numbering(node, context)
case "text":
disableEscaping := i.Node.Attr("disable-output-escaping") == "yes"
content := i.Node.Content()
//don't bother creating a text node for an empty string
if content != "" {
r := context.Output.CreateTextNode(content)
if disableEscaping {
r.DisableOutputEscaping()
}
context.OutputNode.AddChild(r)
}
case "call-template":
name := i.Node.Attr("name")
t, ok := context.Style.NamedTemplates[name]
if ok && t != nil {
// TODO: determine with-params at compile time
var params []*Variable
for _, cur := range i.Children {
switch p := cur.(type) {
case *Variable:
if IsXsltName(p.Node, "with-param") {
p.Apply(node, context)
params = append(params, p)
}
}
}
t.Apply(node, context, params)
}
case "element":
ename := i.Node.Attr("name")
if strings.ContainsRune(ename, '{') {
ename = evalAVT(ename, node, context)
}
r := context.Output.CreateElementNode(ename)
ns := i.Node.Attr("namespace")
if strings.ContainsRune(ns, '{') {
ns = evalAVT(ns, node, context)
}
if ns != "" {
//TODO: search through namespaces in-scope
// not just top-level stylesheet mappings
prefix, _ := context.Style.NamespaceMapping[ns]
r.SetNamespace(prefix, ns)
} else {
// if no namespace specified, use the default namespace
// in scope at this point in the stylesheet
defaultNS := context.DefaultNamespace(i.Node)
if defaultNS != "" {
r.SetNamespace("", defaultNS)
}
}
context.OutputNode.AddChild(r)
context.DeclareStylesheetNamespacesIfRoot(r)
old := context.OutputNode
context.OutputNode = r
attsets := i.Node.Attr("use-attribute-sets")
if attsets != "" {
asets := strings.Fields(attsets)
for _, attsetname := range asets {
a, _ := context.Style.AttributeSets[attsetname]
if a != nil {
a.Apply(node, context)
}
}
}
for _, c := range i.Children {
c.Apply(node, context)
}
context.OutputNode = old
case "comment":
val, _ := i.evalChildrenAsText(node, context)
r := context.Output.CreateCommentNode(val)
context.OutputNode.AddChild(r)
case "processing-instruction":
name := i.Node.Attr("name")
val, _ := i.evalChildrenAsText(node, context)
//TODO: it is an error if val contains "?>"
r := context.Output.CreatePINode(name, val)
context.OutputNode.AddChild(r)
case "attribute":
aname := i.Node.Attr("name")
if strings.ContainsRune(aname, '{') {
aname = evalAVT(aname, node, context)
}
ahref := i.Node.Attr("namespace")
if strings.ContainsRune(ahref, '{') {
ahref = evalAVT(ahref, node, context)
}
val, _ := i.evalChildrenAsText(node, context)
if ahref == "" {
context.OutputNode.SetAttr(aname, val)
} else {
decl := context.OutputNode.DeclaredNamespaces()
dfound := false
for _, d := range decl {
if ahref == d.Uri {
dfound = true
break
}
}
if !dfound && ahref != XML_NAMESPACE {
//TODO: increment val of generated prefix
context.OutputNode.DeclareNamespace("ns_1", ahref)
}
//if a QName, we ignore the prefix when setting namespace
if strings.Contains(aname, ":") {
aname = aname[strings.Index(aname, ":")+1:]
}
context.OutputNode.SetNsAttr(ahref, aname, val)
}
//context.OutputNode.AddChild(a)
case "value-of":
e := xpath.Compile(i.Node.Attr("select"))
disableEscaping := i.Node.Attr("disable-output-escaping") == "yes"
context.RegisterXPathNamespaces(i.Node)
content, _ := context.EvalXPathAsString(node, e)
//don't bother creating a text node for an empty string
if content != "" {
if context.UseCDataSection(context.OutputNode) {
olddata := context.OutputNode.LastChild()
if olddata == nil || olddata.(*xml.CDataNode) == nil {
r := context.Output.CreateCDataNode(content)
context.OutputNode.AddChild(r)
} else {
r := context.Output.CreateCDataNode(olddata.Content() + content)
context.OutputNode.AddChild(r)
olddata.Remove()
}
} else {
r := context.Output.CreateTextNode(content)
if disableEscaping {
r.DisableOutputEscaping()
}
context.OutputNode.AddChild(r)
}
}
case "when":
case "if":
e := xpath.Compile(i.Node.Attr("test"))
if context.EvalXPathAsBoolean(node, e) {
for _, c := range i.Children {
c.Apply(node, context)
}
}
case "attribute-set":
othersets := i.Node.Attr("use-attribute-sets")
if othersets != "" {
asets := strings.Fields(othersets)
for _, attsetname := range asets {
a := context.Style.LookupAttributeSet(attsetname)
if a != nil {
a.Apply(node, context)
}
}
}
for _, c := range i.Children {
c.Apply(node, context)
}
case "fallback":
for _, c := range i.Children {
c.Apply(node, context)
}
case "otherwise":
for _, c := range i.Children {
c.Apply(node, context)
}
case "choose":
for _, c := range i.Children {
inst := c.(*XsltInstruction)
if inst.Node.Name() == "when" {
xp := xpath.Compile(inst.Node.Attr("test"))
if context.EvalXPathAsBoolean(node, xp) {
for _, wc := range inst.Children {
wc.Apply(node, context)
}
break
}
} else {
inst.Apply(node, context)
}
}
case "copy":
//i.copyToOutput(cur, context, false)
switch node.NodeType() {
case xml.XML_TEXT_NODE:
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)
}
case xml.XML_ATTRIBUTE_NODE:
aname := node.Name()
ahref := node.Namespace()
val := node.Content()
if ahref == "" {
context.OutputNode.SetAttr(aname, val)
} else {
context.OutputNode.SetNsAttr(ahref, aname, val)
}
case xml.XML_COMMENT_NODE:
r := context.Output.CreateCommentNode(node.Content())
context.OutputNode.AddChild(r)
case xml.XML_PI_NODE:
name := node.Name()
r := context.Output.CreatePINode(name, node.Content())
context.OutputNode.AddChild(r)
case xml.XML_ELEMENT_NODE:
aname := node.Name()
r := context.Output.CreateElementNode(aname)
context.OutputNode.AddChild(r)
ns := node.Namespace()
if ns != "" {
//TODO: search through namespaces in-scope
prefix, _ := context.Style.NamespaceMapping[ns]
r.SetNamespace(prefix, ns)
}
//copy namespace declarations
for _, decl := range node.DeclaredNamespaces() {
r.DeclareNamespace(decl.Prefix, decl.Uri)
}
old := context.OutputNode
context.OutputNode = r
attsets := i.Node.Attr("use-attribute-sets")
if attsets != "" {
asets := strings.Fields(attsets)
for _, attsetname := range asets {
a := context.Style.LookupAttributeSet(attsetname)
if a != nil {
a.Apply(node, context)
}
}
}
for _, c := range i.Children {
c.Apply(node, context)
}
context.OutputNode = old
}
case "for-each":
scope := i.Node.Attr("select")
e := xpath.Compile(scope)
context.RegisterXPathNamespaces(i.Node)
nodes, _ := context.EvalXPathAsNodeset(node, e)
if i.sorting != nil {
i.Sort(nodes, context)
}
total := len(nodes)
old_curr := context.Current
for j, cur := range nodes {
context.PushStack()
context.XPathContext.SetContextPosition(j+1, total)
context.Current = cur
for _, c := range i.Children {
c.Apply(cur, context)
switch v := c.(type) {
case *Variable:
_ = context.DeclareLocalVariable(v.Name, "", v)
}
}
context.PopStack()
}
context.Current = old_curr
case "copy-of":
scope := i.Node.Attr("select")
e := xpath.Compile(scope)
context.RegisterXPathNamespaces(i.Node)
nodes, _ := context.EvalXPathAsNodeset(node, e)
total := len(nodes)
for j, cur := range nodes {
context.XPathContext.SetContextPosition(j+1, total)
i.copyToOutput(cur, context, true)
}
case "message":
val, _ := i.evalChildrenAsText(node, context)
terminate := i.Node.Attr("terminate")
if terminate == "yes" {
//TODO: fixup error flow to terminate more gracefully
panic(val)
} else {
fmt.Println(val)
}
case "apply-imports":
fmt.Println("TODO handle xsl:apply-imports instruction")
default:
hasFallback := false
for _, c := range i.Children {
switch v := c.(type) {
case *XsltInstruction:
if v.Name == "fallback" {
c.Apply(node, context)
hasFallback = true
break
}
}
}
if !hasFallback {
fmt.Println("UNKNOWN instruction ", i.Name)
}
}
}
func (i *XsltInstruction) copyToOutput(node xml.Node, context *ExecutionContext, recursive bool) {
switch node.NodeType() {
case xml.XML_TEXT_NODE:
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)
}
case xml.XML_ATTRIBUTE_NODE:
aname := node.Name()
ahref := node.Namespace()
val := node.Content()
if ahref == "" {
context.OutputNode.SetAttr(aname, val)
} else {
context.OutputNode.SetNsAttr(ahref, aname, val)
}
case xml.XML_COMMENT_NODE:
r := context.Output.CreateCommentNode(node.Content())
context.OutputNode.AddChild(r)
case xml.XML_PI_NODE:
name := node.Attr("name")
r := context.Output.CreatePINode(name, node.Content())
context.OutputNode.AddChild(r)
case xml.XML_NAMESPACE_DECL:
//in theory this should work
//in practice it's a little complicated due to the fact
//that namespace declarations don't map to the node type
//very well
//will need to revisit
//context.OutputNode.DeclareNamespace(node.Name(), node.Content())
case xml.XML_ELEMENT_NODE:
aname := node.Name()
r := context.Output.CreateElementNode(aname)
context.OutputNode.AddChild(r)
ns := node.Namespace()
if ns != "" {
//TODO: search through namespaces in-scope
prefix, _ := context.Style.NamespaceMapping[ns]
r.SetNamespace(prefix, ns)
} else {
//may need to explicitly reset to empty namespace
def := context.DefaultNamespace(context.OutputNode)
if def != "" {
r.SetNamespace("", "")
}
}
//copy namespace declarations
for _, decl := range node.DeclaredNamespaces() {
r.DeclareNamespace(decl.Prefix, decl.Uri)
}
old := context.OutputNode
context.OutputNode = r
if recursive {
//copy attributes
for _, attr := range node.Attributes() {
i.copyToOutput(attr, context, recursive)
}
for cur := node.FirstChild(); cur != nil; cur = cur.NextSibling() {
i.copyToOutput(cur, context, recursive)
}
}
context.OutputNode = old
case xml.XML_DOCUMENT_NODE:
if recursive {
for cur := node.FirstChild(); cur != nil; cur = cur.NextSibling() {
i.copyToOutput(cur, context, recursive)
}
}
}
}
// If there is no matching template, nil is returned.
func (style *Stylesheet) LookupTemplate(node xml.Node, mode string, context *ExecutionContext) (template *Template) {
name := node.Name()
if node.NodeType() == xml.XML_DOCUMENT_NODE {
name = "/"
}
found := new(list.List)
l := style.ElementMatches[name]
if l != nil {
for i := l.Front(); i != nil; i = i.Next() {
c := i.Value.(*CompiledMatch)
if c.EvalMatch(node, mode, context) {
insertByPriority(found, c)
break
}
}
}
l = style.ElementMatches["*"]
if l != nil {
for i := l.Front(); i != nil; i = i.Next() {
c := i.Value.(*CompiledMatch)
if c.EvalMatch(node, mode, context) {
insertByPriority(found, c)
break
}
}
}
l = style.AttrMatches[name]
if l != nil {
for i := l.Front(); i != nil; i = i.Next() {
c := i.Value.(*CompiledMatch)
if c.EvalMatch(node, mode, context) {
insertByPriority(found, c)
break
}
}
}
l = style.AttrMatches["*"]
if l != nil {
for i := l.Front(); i != nil; i = i.Next() {
c := i.Value.(*CompiledMatch)
if c.EvalMatch(node, mode, context) {
insertByPriority(found, c)
break
}
}
}
//TODO: review order in which we consult generic matches
for i := style.IdKeyMatches.Front(); i != nil; i = i.Next() {
c := i.Value.(*CompiledMatch)
if c.EvalMatch(node, mode, context) {
insertByPriority(found, c)
break
}
}
for i := style.NodeMatches.Front(); i != nil; i = i.Next() {
c := i.Value.(*CompiledMatch)
if c.EvalMatch(node, mode, context) {
insertByPriority(found, c)
break
}
}
for i := style.TextMatches.Front(); i != nil; i = i.Next() {
c := i.Value.(*CompiledMatch)
if c.EvalMatch(node, mode, context) {
insertByPriority(found, c)
break
}
}
for i := style.PIMatches.Front(); i != nil; i = i.Next() {
c := i.Value.(*CompiledMatch)
if c.EvalMatch(node, mode, context) {
insertByPriority(found, c)
break
}
}
for i := style.CommentMatches.Front(); i != nil; i = i.Next() {
c := i.Value.(*CompiledMatch)
if c.EvalMatch(node, mode, context) {
insertByPriority(found, c)
break
}
}
// if there's a match at this import precedence, return
// the one with the highest priority
f := found.Front()
if f != nil {
template = f.Value.(*CompiledMatch).Template
return
}
// no match at this import precedence,
//consult the imported stylesheets
for i := style.Imports.Front(); i != nil; i = i.Next() {
s := i.Value.(*Stylesheet)
t := s.LookupTemplate(node, mode, context)
if t != nil {
return t
}
}
return
}
