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
}
// Returns true if the node matches the pattern
func (m *CompiledMatch) EvalMatch(node xml.Node, mode string, context *ExecutionContext) bool {
cur := node
//false if wrong mode
// #all is an XSLT 2.0 feature
if m.Template != nil && mode != m.Template.Mode && m.Template.Mode != "#all" {
return false
}
for i, step := range m.Steps {
switch step.Op {
case OP_END:
return true
case OP_ROOT:
if cur.NodeType() != xml.XML_DOCUMENT_NODE {
return false
}
case OP_ELEM:
if cur.NodeType() != xml.XML_ELEMENT_NODE {
return false
}
if step.Value != cur.Name() && step.Value != "*" {
return false
}
case OP_NS:
uri := ""
// m.Template.Node
if m.Template != nil {
uri = context.LookupNamespace(step.Value, m.Template.Node)
} else {
uri = context.LookupNamespace(step.Value, nil)
}
if uri != cur.Namespace() {
return false
}
case OP_ATTR:
if cur.NodeType() != xml.XML_ATTRIBUTE_NODE {
return false
}
if step.Value != cur.Name() && step.Value != "*" {
return false
}
case OP_TEXT:
if cur.NodeType() != xml.XML_TEXT_NODE && cur.NodeType() != xml.XML_CDATA_SECTION_NODE {
return false
}
case OP_COMMENT:
if cur.NodeType() != xml.XML_COMMENT_NODE {
return false
}
case OP_ALL:
if cur.NodeType() != xml.XML_ELEMENT_NODE {
return false
}
case OP_PI:
if cur.NodeType() != xml.XML_PI_NODE {
return false
}
case OP_NODE:
switch cur.NodeType() {
case xml.XML_ELEMENT_NODE, xml.XML_CDATA_SECTION_NODE, xml.XML_TEXT_NODE, xml.XML_COMMENT_NODE, xml.XML_PI_NODE:
// matches any of these node types
default:
return false
}
case OP_PARENT:
cur = cur.Parent()
if cur == nil {
return false
}
case OP_ANCESTOR:
next := m.Steps[i+1]
if next.Op != OP_ELEM {
return false
}
for {
cur = cur.Parent()
if cur == nil {
return false
}
if next.Value == cur.Name() {
break
}
}
case OP_PREDICATE:
// see test REC/5.2-16
// see test REC/5.2-22
evalFull := true
if context != nil {
prev := m.Steps[i-1]
if prev.Op == OP_PREDICATE {
prev = m.Steps[i-2]
}
if prev.Op == OP_ELEM || prev.Op == OP_ALL {
parent := cur.Parent()
sibs := context.ChildrenOf(parent)
var clen, pos int
for _, n := range sibs {
if n.NodePtr() == cur.NodePtr() {
pos = clen + 1
clen = clen + 1
} else {
if n.NodeType() == xml.XML_ELEMENT_NODE {
if n.Name() == cur.Name() || prev.Op == OP_ALL {
clen = clen + 1
}
}
}
}
if step.Value == "last()" {
if pos != clen {
return false
}
}
//eval predicate should do special number handling
postest, err := strconv.Atoi(step.Value)
if err == nil {
if pos != postest {
return false
}
}
opos, olen := context.XPathContext.GetContextPosition()
context.XPathContext.SetContextPosition(pos, clen)
result := cur.EvalXPathAsBoolean(step.Value, context)
context.XPathContext.SetContextPosition(opos, olen)
if result == false {
return false
}
evalFull = false
}
}
if evalFull {
//if we made it this far, fall back to the more expensive option of evaluating
// the entire pattern globally
//TODO: cache results on first run for given document
xp := m.pattern
if m.pattern[0] != '/' {
xp = "//" + m.pattern
}
e := xpath.Compile(xp)
o, err := node.Search(e)
if err != nil {
//fmt.Println("ERROR",err)
}
for _, n := range o {
if cur.NodePtr() == n.NodePtr() {
return true
}
}
return false
}
case OP_ID:
//TODO: fix lexer to only put literal inside step value
val := strings.Trim(step.Value, "()\"'")
id := cur.MyDocument().NodeById(val)
if id == nil || node.NodePtr() != id.NodePtr() {
return false
}
case OP_KEY:
// TODO: make this robust
if context != nil {
val := strings.Trim(step.Value, "()")
v := strings.Split(val, ",")
keyname := strings.Trim(v[0], "\"'")
keyval := strings.Trim(v[1], "\"'")
key, _ := context.Style.Keys[keyname]
if key != nil {
o, _ := key.nodes[keyval]
for _, n := range o {
if cur.NodePtr() == n.NodePtr() {
return true
}
}
}
}
return false
default:
return false
}
}
//in theory, OP_END means we never reach here
// in practice, we can generate match patterns
// that are missing OP_END due to how we handle OP_OR
return true
}