// Produce a C.xmlXPathObjectPtr suitable for passing to libxml2
func (n Nodeset) ToXPathNodeset() (ret C.xmlXPathObjectPtr) {
ret = C.xmlXPathNewNodeSet(nil)
for _, node := range n {
C.xmlXPathNodeSetAdd(ret.nodesetval, (*C.xmlNode)(node.NodePtr()))
}
return
}
// Produce a C.xmlXPathObjectPtr marked as a ResultValueTree, suitable for passing to libxml2
func (n Nodeset) ToXPathValueTree() (ret C.xmlXPathObjectPtr) {
if len(n) == 0 {
ret = C.xmlXPathNewValueTree(nil)
return
}
ret = C.xmlXPathNewValueTree(nil)
for _, node := range n {
C.xmlXPathNodeSetAdd(ret.nodesetval, (*C.xmlNode)(node.NodePtr()))
}
//this hack-ish looking line tells libxml2 not to free the RVT
//if we don't do this we get horrible double-free crashes everywhere
ret.boolval = 0
return
}
// Convert an arbitrary value into a C.xmlXPathObjectPtr
// Unrecognised and nil values are converted to empty node sets.
func ValueToXPathObject(val interface{}) (ret C.xmlXPathObjectPtr) {
if val == nil {
//return the empty node set
ret = C.xmlXPathNewNodeSet(nil)
return
}
switch v := val.(type) {
case unsafe.Pointer:
return (C.xmlXPathObjectPtr)(v)
case []unsafe.Pointer:
ptrs := v
if len(ptrs) > 0 {
//default - return a node set
ret = C.xmlXPathNewNodeSet(nil)
for _, p := range ptrs {
C.xmlXPathNodeSetAdd(ret.nodesetval, (*C.xmlNode)(p))
}
} else {
ret = C.xmlXPathNewNodeSet(nil)
return
}
case float64:
ret = C.xmlXPathNewFloat(C.double(v))
case string:
xpathBytes := GetCString([]byte(v))
xpathPtr := unsafe.Pointer(&xpathBytes[0])
ret = C.xmlXPathNewString((*C.xmlChar)(xpathPtr))
default:
typ := reflect.TypeOf(val)
// if a pointer to a struct is passed, get the type of the dereferenced object
if typ.Kind() == reflect.Ptr {
typ = typ.Elem()
}
//log the unknown type, return an empty node set
//fmt.Println("go-resolve wrong-type", typ.Kind())
ret = C.xmlXPathNewNodeSet(nil)
}
return
}