new: added events.on (and other related commands) to trigger specific actions when an events happens

vendor/github.com/antchfx/jsonquery/query.go

@@ -0,0 +1,149 @@
+package jsonquery
+
+import (
+	"fmt"
+
+	"github.com/antchfx/xpath"
+)
+
+var _ xpath.NodeNavigator = &NodeNavigator{}
+
+// CreateXPathNavigator creates a new xpath.NodeNavigator for the specified html.Node.
+func CreateXPathNavigator(top *Node) *NodeNavigator {
+	return &NodeNavigator{cur: top, root: top}
+}
+
+// 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, (t.Current().(*NodeNavigator)).cur)
+	}
+	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 = (t.Current().(*NodeNavigator)).cur
+	}
+	return elem
+}
+
+// NodeNavigator is for navigating JSON document.
+type NodeNavigator struct {
+	root, cur *Node
+}
+
+func (a *NodeNavigator) Current() *Node {
+	return a.cur
+}
+
+func (a *NodeNavigator) NodeType() xpath.NodeType {
+	switch a.cur.Type {
+	case TextNode:
+		return xpath.TextNode
+	case DocumentNode:
+		return xpath.RootNode
+	case ElementNode:
+		return xpath.ElementNode
+	default:
+		panic(fmt.Sprintf("unknown node type %v", a.cur.Type))
+	}
+}
+
+func (a *NodeNavigator) LocalName() string {
+	return a.cur.Data
+
+}
+
+func (a *NodeNavigator) Prefix() string {
+	return ""
+}
+
+func (a *NodeNavigator) Value() string {
+	switch a.cur.Type {
+	case ElementNode:
+		return a.cur.InnerText()
+	case TextNode:
+		return a.cur.Data
+	}
+	return ""
+}
+
+func (a *NodeNavigator) Copy() xpath.NodeNavigator {
+	n := *a
+	return &n
+}
+
+func (a *NodeNavigator) MoveToRoot() {
+	a.cur = a.root
+}
+
+func (a *NodeNavigator) MoveToParent() bool {
+	if n := a.cur.Parent; n != nil {
+		a.cur = n
+		return true
+	}
+	return false
+}
+
+func (x *NodeNavigator) MoveToNextAttribute() bool {
+	return false
+}
+
+func (a *NodeNavigator) MoveToChild() bool {
+	if n := a.cur.FirstChild; n != nil {
+		a.cur = n
+		return true
+	}
+	return false
+}
+
+func (a *NodeNavigator) MoveToFirst() bool {
+	for n := a.cur.PrevSibling; n != nil; n = n.PrevSibling {
+		a.cur = n
+	}
+	return true
+}
+
+func (a *NodeNavigator) String() string {
+	return a.Value()
+}
+
+func (a *NodeNavigator) MoveToNext() bool {
+	if n := a.cur.NextSibling; n != nil {
+		a.cur = n
+		return true
+	}
+	return false
+}
+
+func (a *NodeNavigator) MoveToPrevious() bool {
+	if n := a.cur.PrevSibling; n != nil {
+		a.cur = n
+		return true
+	}
+	return false
+}
+
+func (a *NodeNavigator) MoveTo(other xpath.NodeNavigator) bool {
+	node, ok := other.(*NodeNavigator)
+	if !ok || node.root != a.root {
+		return false
+	}
+	a.cur = node.cur
+	return true
+}