// removeCommentsAndIntertagWhitespace employs horizontal traversal using a queue
func removeCommentsAndIntertagWhitespace(lp interface{}) {
var queue = util.NewQueue(10)
for lp != nil {
lpn := lp.(NdX).Nd
lvl := lp.(NdX).Lvl
for c := lpn.FirstChild; c != nil; c = c.NextSibling {
queue.EnQueue(NdX{c, lvl + 1})
}
// processing
if lpn.Type == html.CommentNode {
dom.RemoveNode(lpn)
}
// extinguish textnodes that do only formatting (spaces, tabs, line breaks)
if lpn.Type == html.TextNode && isSpacey(lpn.Data) {
dom.RemoveNode(lpn)
}
// next node
lp = queue.DeQueue()
}
}
// r is the request to the proxy
// u is the url, that the proxy has called
func ModifyHTML(r *http.Request, u *url.URL, s string) string {
var nums int // counter
// needed to get the current request into the
// "static" recursive functions
var PackageProxyHost = r.Host // port included!
var PackageRemoteHost = fetch.HostFromUrl(u)
fCondenseNode = func(n *html.Node, depth int) (ret string) {
if n.Type == html.ElementNode && n.Data == "script" {
ret += fmt.Sprintf(" var script%v = '[script]'; ", nums)
nums++
return
}
if n.Type == html.ElementNode && n.Data == "style" {
ret += fmt.Sprintf(" .xxx {margin:2px;} ")
return
}
if n.Type == html.ElementNode && n.Data == "img" {
ret += fmt.Sprintf(" [img] %v %v | ", getAttrVal(n.Attr, "alt"), getAttrVal(n.Attr, "src"))
}
if n.Type == html.ElementNode && n.Data == "a" {
ret += "[a]"
}
if n.Type == html.TextNode {
s := n.Data
// s = replTabsNewline.Replace(s)
// s = strings.TrimSpace(s)
if len(s) < 4 {
ret += s
} else if s != "" {
if depth > 0 {
ret += fmt.Sprintf(" [txt%v] %v", depth, s)
} else {
ret += " [txt] " + s
}
}
}
for c := n.FirstChild; c != nil; c = c.NextSibling {
ret += fCondenseNode(c, depth+1)
}
return
}
// --------------------------
// ----------------------
fRecurse = func(n *html.Node) {
if n.Type == html.ElementNode && n.Data == "form" {
hidFld := new(html.Node)
hidFld.Type = html.ElementNode
hidFld.Data = "input"
hidFld.Attr = []html.Attribute{
html.Attribute{Key: "name", Val: "redirect-to"},
html.Attribute{Key: "value", Val: absolutize(getAttrVal(n.Attr, "action"), PackageRemoteHost)},
}
n.AppendChild(hidFld)
submt := new(html.Node)
submt.Type = html.ElementNode
submt.Data = "input"
submt.Attr = []html.Attribute{
html.Attribute{Key: "type", Val: "submit"},
html.Attribute{Key: "value", Val: "subm"},
html.Attribute{Key: "accesskey", Val: "f"},
}
n.AppendChild(submt)
n.Attr = rewriteAttributes(n.Attr, PackageProxyHost, PackageRemoteHost)
}
if n.Type == html.ElementNode && n.Data == "script" {
for i := 0; i < len(n.Attr); i++ {
if n.Attr[i].Key == "src" {
n.Attr[i].Val = emptySrc
}
}
}
if n.Type == html.ElementNode &&
(n.Data == "a" || n.Data == "img" || n.Data == "script" || n.Data == "style") {
s := fCondenseNode(n, 0)
//fmt.Printf("found %v\n", s)
textReplacement := new(html.Node)
textReplacement.Type = html.TextNode
textReplacement.Data = s
attrStore := []html.Attribute{}
if n.Data == "a" || n.Data == "img" {
attrStore = rewriteAttributes(n.Attr, PackageProxyHost, PackageRemoteHost)
}
if n.Data == "img" {
n.Data = "a"
}
if n.Data == "a" {
n.Attr = attrStore
}
// We want to remove all existing children.
// Direct loop impossible, since "NextSibling" is set to nil by Remove().
// Therefore first assembling separately, then removing.
children := make(map[*html.Node]struct{})
for c := n.FirstChild; c != nil; c = c.NextSibling {
children[c] = struct{}{}
}
for k, _ := range children {
n.RemoveChild(k)
}
// we can't put our replacement "under" an image, since img cannot have children
if n.Type == html.ElementNode && n.Data == "img" {
// n.Parent.InsertBefore(textReplacement,n)
dom.InsertAfter(n, textReplacement)
dom.RemoveNode(n)
} else {
n.AppendChild(textReplacement)
}
// Insert a || and a newline before every <a...>
if n.Data == "a" {
prev := n
breaker0 := dom.Nd("text", "||")
n.Parent.InsertBefore(breaker0, prev)
breaker1 := dom.Nd("br")
n.Parent.InsertBefore(breaker1, prev)
breaker2 := dom.Nd("text", "\n")
n.Parent.InsertBefore(breaker2, prev)
}
}
for c := n.FirstChild; c != nil; c = c.NextSibling {
fRecurse(c)
}
}
// --------------------------
// ----------------------
var docRoot *html.Node
var err error
rdr := strings.NewReader(s)
docRoot, err = html.Parse(rdr)
if err != nil {
panic(fmt.Sprintf("3 %v \n", err))
}
fRecurse(docRoot)
var b bytes.Buffer
err = html.Render(&b, docRoot)
if err != nil {
panic(fmt.Sprintf("4 %v \n", err))
}
// log.Printf("len is %v\n", b.Len())
return b.String()
}