729 lines
14 KiB
Go
729 lines
14 KiB
Go
package xpath
|
|
|
|
import (
|
|
"reflect"
|
|
)
|
|
|
|
type iterator interface {
|
|
Current() NodeNavigator
|
|
}
|
|
|
|
// An XPath query interface.
|
|
type query interface {
|
|
// Select traversing iterator returns a query matched node NodeNavigator.
|
|
Select(iterator) NodeNavigator
|
|
|
|
// Evaluate evaluates query and returns values of the current query.
|
|
Evaluate(iterator) interface{}
|
|
|
|
Clone() query
|
|
}
|
|
|
|
// contextQuery is returns current node on the iterator object query.
|
|
type contextQuery struct {
|
|
count int
|
|
Root bool // Moving to root-level node in the current context iterator.
|
|
}
|
|
|
|
func (c *contextQuery) Select(t iterator) (n NodeNavigator) {
|
|
if c.count == 0 {
|
|
c.count++
|
|
n = t.Current().Copy()
|
|
if c.Root {
|
|
n.MoveToRoot()
|
|
}
|
|
}
|
|
return n
|
|
}
|
|
|
|
func (c *contextQuery) Evaluate(iterator) interface{} {
|
|
c.count = 0
|
|
return c
|
|
}
|
|
|
|
func (c *contextQuery) Clone() query {
|
|
return &contextQuery{count: 0, Root: c.Root}
|
|
}
|
|
|
|
// ancestorQuery is an XPath ancestor node query.(ancestor::*|ancestor-self::*)
|
|
type ancestorQuery struct {
|
|
iterator func() NodeNavigator
|
|
|
|
Self bool
|
|
Input query
|
|
Predicate func(NodeNavigator) bool
|
|
}
|
|
|
|
func (a *ancestorQuery) Select(t iterator) NodeNavigator {
|
|
for {
|
|
if a.iterator == nil {
|
|
node := a.Input.Select(t)
|
|
if node == nil {
|
|
return nil
|
|
}
|
|
first := true
|
|
a.iterator = func() NodeNavigator {
|
|
if first && a.Self {
|
|
first = false
|
|
if a.Predicate(node) {
|
|
return node
|
|
}
|
|
}
|
|
for node.MoveToParent() {
|
|
if !a.Predicate(node) {
|
|
break
|
|
}
|
|
return node
|
|
}
|
|
return nil
|
|
}
|
|
}
|
|
|
|
if node := a.iterator(); node != nil {
|
|
return node
|
|
}
|
|
a.iterator = nil
|
|
}
|
|
}
|
|
|
|
func (a *ancestorQuery) Evaluate(t iterator) interface{} {
|
|
a.Input.Evaluate(t)
|
|
a.iterator = nil
|
|
return a
|
|
}
|
|
|
|
func (a *ancestorQuery) Test(n NodeNavigator) bool {
|
|
return a.Predicate(n)
|
|
}
|
|
|
|
func (a *ancestorQuery) Clone() query {
|
|
return &ancestorQuery{Self: a.Self, Input: a.Input.Clone(), Predicate: a.Predicate}
|
|
}
|
|
|
|
// attributeQuery is an XPath attribute node query.(@*)
|
|
type attributeQuery struct {
|
|
iterator func() NodeNavigator
|
|
|
|
Input query
|
|
Predicate func(NodeNavigator) bool
|
|
}
|
|
|
|
func (a *attributeQuery) Select(t iterator) NodeNavigator {
|
|
for {
|
|
if a.iterator == nil {
|
|
node := a.Input.Select(t)
|
|
if node == nil {
|
|
return nil
|
|
}
|
|
node = node.Copy()
|
|
a.iterator = func() NodeNavigator {
|
|
for {
|
|
onAttr := node.MoveToNextAttribute()
|
|
if !onAttr {
|
|
return nil
|
|
}
|
|
if a.Predicate(node) {
|
|
return node
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if node := a.iterator(); node != nil {
|
|
return node
|
|
}
|
|
a.iterator = nil
|
|
}
|
|
}
|
|
|
|
func (a *attributeQuery) Evaluate(t iterator) interface{} {
|
|
a.Input.Evaluate(t)
|
|
a.iterator = nil
|
|
return a
|
|
}
|
|
|
|
func (a *attributeQuery) Test(n NodeNavigator) bool {
|
|
return a.Predicate(n)
|
|
}
|
|
|
|
func (a *attributeQuery) Clone() query {
|
|
return &attributeQuery{Input: a.Input.Clone(), Predicate: a.Predicate}
|
|
}
|
|
|
|
// childQuery is an XPath child node query.(child::*)
|
|
type childQuery struct {
|
|
posit int
|
|
iterator func() NodeNavigator
|
|
|
|
Input query
|
|
Predicate func(NodeNavigator) bool
|
|
}
|
|
|
|
func (c *childQuery) Select(t iterator) NodeNavigator {
|
|
for {
|
|
if c.iterator == nil {
|
|
c.posit = 0
|
|
node := c.Input.Select(t)
|
|
if node == nil {
|
|
return nil
|
|
}
|
|
node = node.Copy()
|
|
first := true
|
|
c.iterator = func() NodeNavigator {
|
|
for {
|
|
if (first && !node.MoveToChild()) || (!first && !node.MoveToNext()) {
|
|
return nil
|
|
}
|
|
first = false
|
|
if c.Predicate(node) {
|
|
return node
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if node := c.iterator(); node != nil {
|
|
c.posit++
|
|
return node
|
|
}
|
|
c.iterator = nil
|
|
}
|
|
}
|
|
|
|
func (c *childQuery) Evaluate(t iterator) interface{} {
|
|
c.Input.Evaluate(t)
|
|
c.iterator = nil
|
|
return c
|
|
}
|
|
|
|
func (c *childQuery) Test(n NodeNavigator) bool {
|
|
return c.Predicate(n)
|
|
}
|
|
|
|
func (c *childQuery) Clone() query {
|
|
return &childQuery{Input: c.Input.Clone(), Predicate: c.Predicate}
|
|
}
|
|
|
|
// position returns a position of current NodeNavigator.
|
|
func (c *childQuery) position() int {
|
|
return c.posit
|
|
}
|
|
|
|
// descendantQuery is an XPath descendant node query.(descendant::* | descendant-or-self::*)
|
|
type descendantQuery struct {
|
|
iterator func() NodeNavigator
|
|
posit int
|
|
|
|
Self bool
|
|
Input query
|
|
Predicate func(NodeNavigator) bool
|
|
}
|
|
|
|
func (d *descendantQuery) Select(t iterator) NodeNavigator {
|
|
for {
|
|
if d.iterator == nil {
|
|
d.posit = 0
|
|
node := d.Input.Select(t)
|
|
if node == nil {
|
|
return nil
|
|
}
|
|
node = node.Copy()
|
|
level := 0
|
|
first := true
|
|
d.iterator = func() NodeNavigator {
|
|
if first && d.Self {
|
|
first = false
|
|
if d.Predicate(node) {
|
|
return node
|
|
}
|
|
}
|
|
|
|
for {
|
|
if node.MoveToChild() {
|
|
level++
|
|
} else {
|
|
for {
|
|
if level == 0 {
|
|
return nil
|
|
}
|
|
if node.MoveToNext() {
|
|
break
|
|
}
|
|
node.MoveToParent()
|
|
level--
|
|
}
|
|
}
|
|
if d.Predicate(node) {
|
|
return node
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if node := d.iterator(); node != nil {
|
|
d.posit++
|
|
return node
|
|
}
|
|
d.iterator = nil
|
|
}
|
|
}
|
|
|
|
func (d *descendantQuery) Evaluate(t iterator) interface{} {
|
|
d.Input.Evaluate(t)
|
|
d.iterator = nil
|
|
return d
|
|
}
|
|
|
|
func (d *descendantQuery) Test(n NodeNavigator) bool {
|
|
return d.Predicate(n)
|
|
}
|
|
|
|
// position returns a position of current NodeNavigator.
|
|
func (d *descendantQuery) position() int {
|
|
return d.posit
|
|
}
|
|
|
|
func (d *descendantQuery) Clone() query {
|
|
return &descendantQuery{Self: d.Self, Input: d.Input.Clone(), Predicate: d.Predicate}
|
|
}
|
|
|
|
// followingQuery is an XPath following node query.(following::*|following-sibling::*)
|
|
type followingQuery struct {
|
|
iterator func() NodeNavigator
|
|
|
|
Input query
|
|
Sibling bool // The matching sibling node of current node.
|
|
Predicate func(NodeNavigator) bool
|
|
}
|
|
|
|
func (f *followingQuery) Select(t iterator) NodeNavigator {
|
|
for {
|
|
if f.iterator == nil {
|
|
node := f.Input.Select(t)
|
|
if node == nil {
|
|
return nil
|
|
}
|
|
node = node.Copy()
|
|
if f.Sibling {
|
|
f.iterator = func() NodeNavigator {
|
|
for {
|
|
if !node.MoveToNext() {
|
|
return nil
|
|
}
|
|
if f.Predicate(node) {
|
|
return node
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
var q query // descendant query
|
|
f.iterator = func() NodeNavigator {
|
|
for {
|
|
if q == nil {
|
|
for !node.MoveToNext() {
|
|
if !node.MoveToParent() {
|
|
return nil
|
|
}
|
|
}
|
|
q = &descendantQuery{
|
|
Self: true,
|
|
Input: &contextQuery{},
|
|
Predicate: f.Predicate,
|
|
}
|
|
t.Current().MoveTo(node)
|
|
}
|
|
if node := q.Select(t); node != nil {
|
|
return node
|
|
}
|
|
q = nil
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if node := f.iterator(); node != nil {
|
|
return node
|
|
}
|
|
f.iterator = nil
|
|
}
|
|
}
|
|
|
|
func (f *followingQuery) Evaluate(t iterator) interface{} {
|
|
f.Input.Evaluate(t)
|
|
return f
|
|
}
|
|
|
|
func (f *followingQuery) Test(n NodeNavigator) bool {
|
|
return f.Predicate(n)
|
|
}
|
|
|
|
func (f *followingQuery) Clone() query {
|
|
return &followingQuery{Input: f.Input.Clone(), Sibling: f.Sibling, Predicate: f.Predicate}
|
|
}
|
|
|
|
// precedingQuery is an XPath preceding node query.(preceding::*)
|
|
type precedingQuery struct {
|
|
iterator func() NodeNavigator
|
|
Input query
|
|
Sibling bool // The matching sibling node of current node.
|
|
Predicate func(NodeNavigator) bool
|
|
}
|
|
|
|
func (p *precedingQuery) Select(t iterator) NodeNavigator {
|
|
for {
|
|
if p.iterator == nil {
|
|
node := p.Input.Select(t)
|
|
if node == nil {
|
|
return nil
|
|
}
|
|
node = node.Copy()
|
|
if p.Sibling {
|
|
p.iterator = func() NodeNavigator {
|
|
for {
|
|
for !node.MoveToPrevious() {
|
|
return nil
|
|
}
|
|
if p.Predicate(node) {
|
|
return node
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
var q query
|
|
p.iterator = func() NodeNavigator {
|
|
for {
|
|
if q == nil {
|
|
for !node.MoveToPrevious() {
|
|
if !node.MoveToParent() {
|
|
return nil
|
|
}
|
|
}
|
|
q = &descendantQuery{
|
|
Self: true,
|
|
Input: &contextQuery{},
|
|
Predicate: p.Predicate,
|
|
}
|
|
t.Current().MoveTo(node)
|
|
}
|
|
if node := q.Select(t); node != nil {
|
|
return node
|
|
}
|
|
q = nil
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if node := p.iterator(); node != nil {
|
|
return node
|
|
}
|
|
p.iterator = nil
|
|
}
|
|
}
|
|
|
|
func (p *precedingQuery) Evaluate(t iterator) interface{} {
|
|
p.Input.Evaluate(t)
|
|
return p
|
|
}
|
|
|
|
func (p *precedingQuery) Test(n NodeNavigator) bool {
|
|
return p.Predicate(n)
|
|
}
|
|
|
|
func (p *precedingQuery) Clone() query {
|
|
return &precedingQuery{Input: p.Input.Clone(), Sibling: p.Sibling, Predicate: p.Predicate}
|
|
}
|
|
|
|
// parentQuery is an XPath parent node query.(parent::*)
|
|
type parentQuery struct {
|
|
Input query
|
|
Predicate func(NodeNavigator) bool
|
|
}
|
|
|
|
func (p *parentQuery) Select(t iterator) NodeNavigator {
|
|
for {
|
|
node := p.Input.Select(t)
|
|
if node == nil {
|
|
return nil
|
|
}
|
|
node = node.Copy()
|
|
if node.MoveToParent() && p.Predicate(node) {
|
|
return node
|
|
}
|
|
}
|
|
}
|
|
|
|
func (p *parentQuery) Evaluate(t iterator) interface{} {
|
|
p.Input.Evaluate(t)
|
|
return p
|
|
}
|
|
|
|
func (p *parentQuery) Clone() query {
|
|
return &parentQuery{Input: p.Input.Clone(), Predicate: p.Predicate}
|
|
}
|
|
|
|
func (p *parentQuery) Test(n NodeNavigator) bool {
|
|
return p.Predicate(n)
|
|
}
|
|
|
|
// selfQuery is an Self node query.(self::*)
|
|
type selfQuery struct {
|
|
Input query
|
|
Predicate func(NodeNavigator) bool
|
|
}
|
|
|
|
func (s *selfQuery) Select(t iterator) NodeNavigator {
|
|
for {
|
|
node := s.Input.Select(t)
|
|
if node == nil {
|
|
return nil
|
|
}
|
|
|
|
if s.Predicate(node) {
|
|
return node
|
|
}
|
|
}
|
|
}
|
|
|
|
func (s *selfQuery) Evaluate(t iterator) interface{} {
|
|
s.Input.Evaluate(t)
|
|
return s
|
|
}
|
|
|
|
func (s *selfQuery) Test(n NodeNavigator) bool {
|
|
return s.Predicate(n)
|
|
}
|
|
|
|
func (s *selfQuery) Clone() query {
|
|
return &selfQuery{Input: s.Input.Clone(), Predicate: s.Predicate}
|
|
}
|
|
|
|
// filterQuery is an XPath query for predicate filter.
|
|
type filterQuery struct {
|
|
Input query
|
|
Predicate query
|
|
}
|
|
|
|
func (f *filterQuery) do(t iterator) bool {
|
|
val := reflect.ValueOf(f.Predicate.Evaluate(t))
|
|
switch val.Kind() {
|
|
case reflect.Bool:
|
|
return val.Bool()
|
|
case reflect.String:
|
|
return len(val.String()) > 0
|
|
case reflect.Float64:
|
|
pt := float64(getNodePosition(f.Input))
|
|
return int(val.Float()) == int(pt)
|
|
default:
|
|
if q, ok := f.Predicate.(query); ok {
|
|
return q.Select(t) != nil
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
|
|
func (f *filterQuery) Select(t iterator) NodeNavigator {
|
|
for {
|
|
node := f.Input.Select(t)
|
|
if node == nil {
|
|
return node
|
|
}
|
|
node = node.Copy()
|
|
//fmt.Println(node.LocalName())
|
|
|
|
t.Current().MoveTo(node)
|
|
if f.do(t) {
|
|
return node
|
|
}
|
|
}
|
|
}
|
|
|
|
func (f *filterQuery) Evaluate(t iterator) interface{} {
|
|
f.Input.Evaluate(t)
|
|
return f
|
|
}
|
|
|
|
func (f *filterQuery) Clone() query {
|
|
return &filterQuery{Input: f.Input.Clone(), Predicate: f.Predicate.Clone()}
|
|
}
|
|
|
|
// functionQuery is an XPath function that call a function to returns
|
|
// value of current NodeNavigator node.
|
|
type functionQuery struct {
|
|
Input query // Node Set
|
|
Func func(query, iterator) interface{} // The xpath function.
|
|
}
|
|
|
|
func (f *functionQuery) Select(t iterator) NodeNavigator {
|
|
return nil
|
|
}
|
|
|
|
// Evaluate call a specified function that will returns the
|
|
// following value type: number,string,boolean.
|
|
func (f *functionQuery) Evaluate(t iterator) interface{} {
|
|
return f.Func(f.Input, t)
|
|
}
|
|
|
|
func (f *functionQuery) Clone() query {
|
|
return &functionQuery{Input: f.Input.Clone(), Func: f.Func}
|
|
}
|
|
|
|
// constantQuery is an XPath constant operand.
|
|
type constantQuery struct {
|
|
Val interface{}
|
|
}
|
|
|
|
func (c *constantQuery) Select(t iterator) NodeNavigator {
|
|
return nil
|
|
}
|
|
|
|
func (c *constantQuery) Evaluate(t iterator) interface{} {
|
|
return c.Val
|
|
}
|
|
|
|
func (c *constantQuery) Clone() query {
|
|
return c
|
|
}
|
|
|
|
// logicalQuery is an XPath logical expression.
|
|
type logicalQuery struct {
|
|
Left, Right query
|
|
|
|
Do func(iterator, interface{}, interface{}) interface{}
|
|
}
|
|
|
|
func (l *logicalQuery) Select(t iterator) NodeNavigator {
|
|
// When a XPath expr is logical expression.
|
|
node := t.Current().Copy()
|
|
val := l.Evaluate(t)
|
|
switch val.(type) {
|
|
case bool:
|
|
if val.(bool) == true {
|
|
return node
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func (l *logicalQuery) Evaluate(t iterator) interface{} {
|
|
m := l.Left.Evaluate(t)
|
|
n := l.Right.Evaluate(t)
|
|
return l.Do(t, m, n)
|
|
}
|
|
|
|
func (l *logicalQuery) Clone() query {
|
|
return &logicalQuery{Left: l.Left.Clone(), Right: l.Right.Clone(), Do: l.Do}
|
|
}
|
|
|
|
// numericQuery is an XPath numeric operator expression.
|
|
type numericQuery struct {
|
|
Left, Right query
|
|
|
|
Do func(interface{}, interface{}) interface{}
|
|
}
|
|
|
|
func (n *numericQuery) Select(t iterator) NodeNavigator {
|
|
return nil
|
|
}
|
|
|
|
func (n *numericQuery) Evaluate(t iterator) interface{} {
|
|
m := n.Left.Evaluate(t)
|
|
k := n.Right.Evaluate(t)
|
|
return n.Do(m, k)
|
|
}
|
|
|
|
func (n *numericQuery) Clone() query {
|
|
return &numericQuery{Left: n.Left.Clone(), Right: n.Right.Clone(), Do: n.Do}
|
|
}
|
|
|
|
type booleanQuery struct {
|
|
IsOr bool
|
|
Left, Right query
|
|
iterator func() NodeNavigator
|
|
}
|
|
|
|
func (b *booleanQuery) Select(t iterator) NodeNavigator {
|
|
if b.iterator == nil {
|
|
var list []NodeNavigator
|
|
i := 0
|
|
root := t.Current().Copy()
|
|
if b.IsOr {
|
|
for {
|
|
node := b.Left.Select(t)
|
|
if node == nil {
|
|
break
|
|
}
|
|
node = node.Copy()
|
|
list = append(list, node)
|
|
}
|
|
t.Current().MoveTo(root)
|
|
for {
|
|
node := b.Right.Select(t)
|
|
if node == nil {
|
|
break
|
|
}
|
|
node = node.Copy()
|
|
list = append(list, node)
|
|
}
|
|
} else {
|
|
var m []NodeNavigator
|
|
var n []NodeNavigator
|
|
for {
|
|
node := b.Left.Select(t)
|
|
if node == nil {
|
|
break
|
|
}
|
|
node = node.Copy()
|
|
list = append(m, node)
|
|
}
|
|
t.Current().MoveTo(root)
|
|
for {
|
|
node := b.Right.Select(t)
|
|
if node == nil {
|
|
break
|
|
}
|
|
node = node.Copy()
|
|
list = append(n, node)
|
|
}
|
|
for _, k := range m {
|
|
for _, j := range n {
|
|
if k == j {
|
|
list = append(list, k)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
b.iterator = func() NodeNavigator {
|
|
if i >= len(list) {
|
|
return nil
|
|
}
|
|
node := list[i]
|
|
i++
|
|
return node
|
|
}
|
|
}
|
|
return b.iterator()
|
|
}
|
|
|
|
func (b *booleanQuery) Evaluate(t iterator) interface{} {
|
|
m := b.Left.Evaluate(t)
|
|
if m.(bool) == b.IsOr {
|
|
return m
|
|
}
|
|
return b.Right.Evaluate(t)
|
|
}
|
|
|
|
func (b *booleanQuery) Clone() query {
|
|
return &booleanQuery{IsOr: b.IsOr, Left: b.Left.Clone(), Right: b.Right.Clone()}
|
|
}
|
|
|
|
func getNodePosition(q query) int {
|
|
type Position interface {
|
|
position() int
|
|
}
|
|
if count, ok := q.(Position); ok {
|
|
return count.position()
|
|
}
|
|
return 1
|
|
}
|