add Contents() and Children() with tests.

traversal.go

@@ -3,7 +3,6 @@ package goquery
 import (
 	"code.google.com/p/cascadia"
 	"exp/html"
-	"strings"
 )
 
 // TODO : Maybe make the Document's Root return a Selection, Find() on the
@@ -40,24 +39,52 @@ func findWithContext(selector string, nodes ...*html.Node) []*html.Node {
 	return matches
 }
 
-// TODO : Tests and doc for contents and children
-
+// Contents() gets the children of each element in the Selection,
+// including text and comment nodes. It returns a new Selection object
+// containing these elements.
 func (this *Selection) Contents() *Selection {
-	var matches []*html.Node
-
-	for _, n := range this.Nodes {
-		matches = appendWithoutDuplicates(matches, getChildren(n, false))
-	}
-	return pushStack(this, matches)
+	return pushStack(this, getSelectionChildren(this, false))
 }
 
-func (this *Selection) Children() *Selection {
-	var matches []*html.Node
-
-	for _, n := range this.Nodes {
-		matches = appendWithoutDuplicates(matches, getChildren(n, true))
+// ContentsFiltered() gets the children of each element in the Selection,
+// filtered by the specified selector. It returns a new Selection
+// object containing these elements. Since selectors only act on Element nodes,
+// this function is an alias to ChildrenFiltered() unless the selector is empty,
+// in which case it is an alias to Contents().
+func (this *Selection) ContentsFiltered(selector string) *Selection {
+	if selector != "" {
+		return this.ChildrenFiltered(selector)
 	}
-	return pushStack(this, matches)
+	return this.Contents()
+}
+
+// Children() gets the child elements of each element in the Selection.
+// It returns a new Selection object containing these elements.
+func (this *Selection) Children() *Selection {
+	return pushStack(this, getSelectionChildren(this, true))
+}
+
+// ChildrenFiltered() gets the child elements of each element in the Selection,
+// filtered by the specified selector. It returns a new
+// Selection object containing these elements.
+func (this *Selection) ChildrenFiltered(selector string) *Selection {
+	// Get the Children() unfiltered
+	nodes := getSelectionChildren(this, true)
+	// Create a temporary Selection to filter using winnow
+	sel := &Selection{nodes, this.document, nil}
+	// Filter based on selector
+	nodes = winnow(sel, selector, true)
+	// Push on the stack and return the "real" Selection
+	return pushStack(this, nodes)
+}
+
+// Return the child nodes of each node in the Selection object, without
+// duplicates.
+func getSelectionChildren(s *Selection, elemOnly bool) (result []*html.Node) {
+	for _, n := range s.Nodes {
+		result = appendWithoutDuplicates(result, getChildren(n, elemOnly))
+	}
+	return
 }
 
 // Return the immediate children of the node, filtered on element nodes only