Skip to content
Permalink
Branch: master
Find file Copy path
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
265 lines (234 sloc) 5.25 KB
/*
Package xmlquery provides extract data from XML documents using XPath expression.
*/
package xmlquery
import (
"fmt"
"strings"
"github.com/antchfx/xpath"
)
// SelectElements finds child elements with the specified name.
func (n *Node) SelectElements(name string) []*Node {
return Find(n, name)
}
// SelectElement finds child elements with the specified name.
func (n *Node) SelectElement(name string) *Node {
return FindOne(n, name)
}
// SelectAttr returns the attribute value with the specified name.
func (n *Node) SelectAttr(name string) string {
if n.Type == AttributeNode {
if n.Data == name {
return n.InnerText()
}
return ""
}
var local, space string
local = name
if i := strings.Index(name, ":"); i > 0 {
space = name[:i]
local = name[i+1:]
}
for _, attr := range n.Attr {
if attr.Name.Local == local && attr.Name.Space == space {
return attr.Value
}
}
return ""
}
var _ xpath.NodeNavigator = &NodeNavigator{}
// CreateXPathNavigator creates a new xpath.NodeNavigator for the specified html.Node.
func CreateXPathNavigator(top *Node) *NodeNavigator {
return &NodeNavigator{curr: top, root: top, attr: -1}
}
func getCurrentNode(it *xpath.NodeIterator) *Node {
n := it.Current().(*NodeNavigator)
if n.NodeType() == xpath.AttributeNode {
childNode := &Node{
Type: TextNode,
Data: n.Value(),
}
return &Node{
Type: AttributeNode,
Data: n.LocalName(),
FirstChild: childNode,
LastChild: childNode,
}
}
return n.curr
}
// Find searches the Node that matches by the specified XPath expr.
func Find(top *Node, expr string) []*Node {
exp, err := xpath.Compile(expr)
if err != nil {
panic(err)
}
t := exp.Select(CreateXPathNavigator(top))
var elems []*Node
for t.MoveNext() {
elems = append(elems, getCurrentNode(t))
}
return elems
}
// FindOne searches the Node that matches by the specified XPath expr,
// and returns first element of matched.
func FindOne(top *Node, expr string) *Node {
exp, err := xpath.Compile(expr)
if err != nil {
panic(err)
}
t := exp.Select(CreateXPathNavigator(top))
var elem *Node
if t.MoveNext() {
elem = getCurrentNode(t)
}
return elem
}
// FindEach searches the html.Node and calls functions cb.
// Important: this method has deprecated, recommend use for .. = range Find(){}.
func FindEach(top *Node, expr string, cb func(int, *Node)) {
for i, n := range Find(top, expr) {
cb(i, n)
}
}
// FindEachWithBreak functions the same as FindEach but allows you
// to break the loop by returning false from your callback function, cb.
// Important: this method has deprecated, recommend use for .. = range Find(){}.
func FindEachWithBreak(top *Node, expr string, cb func(int, *Node) bool) {
for i, n := range Find(top, expr) {
if !cb(i, n) {
break
}
}
}
type NodeNavigator struct {
root, curr *Node
attr int
}
func (x *NodeNavigator) Current() *Node {
return x.curr
}
func (x *NodeNavigator) NodeType() xpath.NodeType {
switch x.curr.Type {
case CommentNode:
return xpath.CommentNode
case TextNode:
return xpath.TextNode
case DeclarationNode, DocumentNode:
return xpath.RootNode
case ElementNode:
if x.attr != -1 {
return xpath.AttributeNode
}
return xpath.ElementNode
}
panic(fmt.Sprintf("unknown XML node type: %v", x.curr.Type))
}
func (x *NodeNavigator) LocalName() string {
if x.attr != -1 {
return x.curr.Attr[x.attr].Name.Local
}
return x.curr.Data
}
func (x *NodeNavigator) Prefix() string {
if x.NodeType() == xpath.AttributeNode {
if x.attr != -1 {
return x.curr.Attr[x.attr].Name.Space
}
return ""
}
return x.curr.Prefix
}
func (x *NodeNavigator) Value() string {
switch x.curr.Type {
case CommentNode:
return x.curr.Data
case ElementNode:
if x.attr != -1 {
return x.curr.Attr[x.attr].Value
}
return x.curr.InnerText()
case TextNode:
return x.curr.Data
}
return ""
}
func (x *NodeNavigator) Copy() xpath.NodeNavigator {
n := *x
return &n
}
func (x *NodeNavigator) MoveToRoot() {
x.curr = x.root
}
func (x *NodeNavigator) MoveToParent() bool {
if x.attr != -1 {
x.attr = -1
return true
} else if node := x.curr.Parent; node != nil {
x.curr = node
return true
}
return false
}
func (x *NodeNavigator) MoveToNextAttribute() bool {
if x.attr >= len(x.curr.Attr)-1 {
return false
}
x.attr++
return true
}
func (x *NodeNavigator) MoveToChild() bool {
if x.attr != -1 {
return false
}
if node := x.curr.FirstChild; node != nil {
x.curr = node
return true
}
return false
}
func (x *NodeNavigator) MoveToFirst() bool {
if x.attr != -1 || x.curr.PrevSibling == nil {
return false
}
for {
node := x.curr.PrevSibling
if node == nil {
break
}
x.curr = node
}
return true
}
func (x *NodeNavigator) String() string {
return x.Value()
}
func (x *NodeNavigator) MoveToNext() bool {
if x.attr != -1 {
return false
}
if node := x.curr.NextSibling; node != nil {
x.curr = node
return true
}
return false
}
func (x *NodeNavigator) MoveToPrevious() bool {
if x.attr != -1 {
return false
}
if node := x.curr.PrevSibling; node != nil {
x.curr = node
return true
}
return false
}
func (x *NodeNavigator) MoveTo(other xpath.NodeNavigator) bool {
node, ok := other.(*NodeNavigator)
if !ok || node.root != x.root {
return false
}
x.curr = node.curr
x.attr = node.attr
return true
}
You can’t perform that action at this time.