mirror of
https://github.com/golang/go
synced 2024-11-25 01:17:56 -07:00
html: add a Render function.
R=mikesamuel, andybalholm CC=golang-dev https://golang.org/cl/5218041
This commit is contained in:
Nigel Tao
parent
e63fcd613f
commit
be8b4d943f
@ -12,6 +12,7 @@ GOFILES=\
|
||||
escape.go\
|
||||
node.go\
|
||||
parse.go\
|
||||
render.go\
|
||||
token.go\
|
||||
|
||||
include ../../Make.pkg
|
||||
|
||||
@ -6,6 +6,7 @@ package html
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"os"
|
||||
"strings"
|
||||
"utf8"
|
||||
)
|
||||
@ -184,10 +185,12 @@ func unescape(b []byte) []byte {
|
||||
|
||||
const escapedChars = `&'<>"`
|
||||
|
||||
func escape(buf *bytes.Buffer, s string) {
|
||||
func escape(w writer, s string) os.Error {
|
||||
i := strings.IndexAny(s, escapedChars)
|
||||
for i != -1 {
|
||||
buf.WriteString(s[0:i])
|
||||
if _, err := w.WriteString(s[:i]); err != nil {
|
||||
return err
|
||||
}
|
||||
var esc string
|
||||
switch s[i] {
|
||||
case '&':
|
||||
@ -204,10 +207,13 @@ func escape(buf *bytes.Buffer, s string) {
|
||||
panic("unrecognized escape character")
|
||||
}
|
||||
s = s[i+1:]
|
||||
buf.WriteString(esc)
|
||||
if _, err := w.WriteString(esc); err != nil {
|
||||
return err
|
||||
}
|
||||
i = strings.IndexAny(s, escapedChars)
|
||||
}
|
||||
buf.WriteString(s)
|
||||
_, err := w.WriteString(s)
|
||||
return err
|
||||
}
|
||||
|
||||
// EscapeString escapes special characters like "<" to become "<". It
|
||||
|
||||
@ -134,7 +134,7 @@ func TestParser(t *testing.T) {
|
||||
if err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
actual, err := dump(doc)
|
||||
got, err := dump(doc)
|
||||
if err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
@ -147,9 +147,24 @@ func TestParser(t *testing.T) {
|
||||
if err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
expected := string(b)
|
||||
if actual != expected {
|
||||
t.Errorf("%s test #%d %q, actual vs expected:\n----\n%s----\n%s----", filename, i, text, actual, expected)
|
||||
if want := string(b); got != want {
|
||||
t.Errorf("%s test #%d %q, got vs want:\n----\n%s----\n%s----", filename, i, text, got, want)
|
||||
}
|
||||
// Check that rendering and re-parsing results in an identical tree.
|
||||
pr, pw := io.Pipe()
|
||||
go func() {
|
||||
pw.CloseWithError(Render(pw, doc))
|
||||
}()
|
||||
doc1, err := Parse(pr)
|
||||
if err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
got1, err := dump(doc1)
|
||||
if err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
if got != got1 {
|
||||
t.Errorf("%s test #%d %q, got vs got1:\n----\n%s----\n%s----", filename, i, text, got, got1)
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
159
src/pkg/html/render.go
Normal file
159
src/pkg/html/render.go
Normal file
@ -0,0 +1,159 @@
|
||||
// Copyright 2011 The Go Authors. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
package html
|
||||
|
||||
import (
|
||||
"bufio"
|
||||
"fmt"
|
||||
"io"
|
||||
"os"
|
||||
)
|
||||
|
||||
type writer interface {
|
||||
io.Writer
|
||||
WriteByte(byte) os.Error
|
||||
WriteString(string) (int, os.Error)
|
||||
}
|
||||
|
||||
// Render renders the parse tree n to the given writer.
|
||||
//
|
||||
// For 'well-formed' parse trees, calling Parse on the output of Render will
|
||||
// result in a clone of the original tree.
|
||||
//
|
||||
// 'Well-formed' is not formally specified, but calling Parse on arbitrary
|
||||
// input results in a 'well-formed' parse tree if Parse does not return an
|
||||
// error. Programmatically constructed trees are typically also 'well-formed',
|
||||
// but it is possible to construct a tree that, when rendered and re-parsed,
|
||||
// results in a different tree. A simple example is that a solitary text node
|
||||
// would become a tree containing <html>, <head> and <body> elements. Another
|
||||
// example is that the programmatic equivalent of "a<head>b</head>c" becomes
|
||||
// "<html><head><head/><body>abc</body></html>".
|
||||
//
|
||||
// Comment nodes are elided from the output, analogous to Parse skipping over
|
||||
// any <!--comment--> input.
|
||||
func Render(w io.Writer, n *Node) os.Error {
|
||||
if x, ok := w.(writer); ok {
|
||||
return render(x, n)
|
||||
}
|
||||
buf := bufio.NewWriter(w)
|
||||
if err := render(buf, n); err != nil {
|
||||
return err
|
||||
}
|
||||
return buf.Flush()
|
||||
}
|
||||
|
||||
func render(w writer, n *Node) os.Error {
|
||||
// Render non-element nodes; these are the easy cases.
|
||||
switch n.Type {
|
||||
case ErrorNode:
|
||||
return os.NewError("html: cannot render an ErrorNode node")
|
||||
case TextNode:
|
||||
return escape(w, n.Data)
|
||||
case DocumentNode:
|
||||
for _, c := range n.Child {
|
||||
if err := render(w, c); err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
return nil
|
||||
case ElementNode:
|
||||
// No-op.
|
||||
case CommentNode:
|
||||
return nil
|
||||
case DoctypeNode:
|
||||
if _, err := w.WriteString("<!DOCTYPE "); err != nil {
|
||||
return err
|
||||
}
|
||||
if _, err := w.WriteString(n.Data); err != nil {
|
||||
return err
|
||||
}
|
||||
return w.WriteByte('>')
|
||||
default:
|
||||
return os.NewError("html: unknown node type")
|
||||
}
|
||||
|
||||
// TODO: figure out what to do with <script>, <style>, <noembed>,
|
||||
// <noframes> and <noscript> elements. A tentative plan:
|
||||
// 1. render the <xxx> opening tag as normal.
|
||||
// 2. maybe error out if any child is not a text node.
|
||||
// 3. render the text nodes (without escaping??).
|
||||
// 4. maybe error out if `</xxx` is a case-insensitive substring of the
|
||||
// concatenation of the children's data.
|
||||
// 5. maybe error out if the concatenation of the children's data contains an
|
||||
// unbalanced escaping text span start ("<!--") not followed by an end ("-->").
|
||||
// 6. render the closing tag as normal.
|
||||
|
||||
// Render the <xxx> opening tag.
|
||||
if err := w.WriteByte('<'); err != nil {
|
||||
return err
|
||||
}
|
||||
if _, err := w.WriteString(n.Data); err != nil {
|
||||
return err
|
||||
}
|
||||
for _, a := range n.Attr {
|
||||
if err := w.WriteByte(' '); err != nil {
|
||||
return err
|
||||
}
|
||||
if _, err := w.WriteString(a.Key); err != nil {
|
||||
return err
|
||||
}
|
||||
if _, err := w.WriteString(`="`); err != nil {
|
||||
return err
|
||||
}
|
||||
if err := escape(w, a.Val); err != nil {
|
||||
return err
|
||||
}
|
||||
if err := w.WriteByte('"'); err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
if voidElements[n.Data] {
|
||||
if len(n.Child) != 0 {
|
||||
return fmt.Errorf("html: void element <%s> has child nodes", n.Data)
|
||||
}
|
||||
_, err := w.WriteString("/>")
|
||||
return err
|
||||
}
|
||||
if err := w.WriteByte('>'); err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
// Render any child nodes.
|
||||
for _, c := range n.Child {
|
||||
if err := render(w, c); err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
|
||||
// Render the </xxx> closing tag.
|
||||
if _, err := w.WriteString("</"); err != nil {
|
||||
return err
|
||||
}
|
||||
if _, err := w.WriteString(n.Data); err != nil {
|
||||
return err
|
||||
}
|
||||
return w.WriteByte('>')
|
||||
}
|
||||
|
||||
// Section 13.1.2, "Elements", gives this list of void elements. Void elements
|
||||
// are those that can't have any contents.
|
||||
var voidElements = map[string]bool{
|
||||
"area": true,
|
||||
"base": true,
|
||||
"br": true,
|
||||
"col": true,
|
||||
"command": true,
|
||||
"embed": true,
|
||||
"hr": true,
|
||||
"img": true,
|
||||
"input": true,
|
||||
"keygen": true,
|
||||
"link": true,
|
||||
"meta": true,
|
||||
"param": true,
|
||||
"source": true,
|
||||
"track": true,
|
||||
"wbr": true,
|
||||
}
|
||||
111
src/pkg/html/render_test.go
Normal file
111
src/pkg/html/render_test.go
Normal file
@ -0,0 +1,111 @@
|
||||
// Copyright 2010 The Go Authors. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
package html
|
||||
|
||||
import (
|
||||
"bytes"
|
||||
"testing"
|
||||
)
|
||||
|
||||
func TestRenderer(t *testing.T) {
|
||||
n := &Node{
|
||||
Type: ElementNode,
|
||||
Data: "html",
|
||||
Child: []*Node{
|
||||
&Node{
|
||||
Type: ElementNode,
|
||||
Data: "head",
|
||||
},
|
||||
&Node{
|
||||
Type: ElementNode,
|
||||
Data: "body",
|
||||
Child: []*Node{
|
||||
&Node{
|
||||
Type: TextNode,
|
||||
Data: "0<1",
|
||||
},
|
||||
&Node{
|
||||
Type: ElementNode,
|
||||
Data: "p",
|
||||
Attr: []Attribute{
|
||||
Attribute{
|
||||
Key: "id",
|
||||
Val: "A",
|
||||
},
|
||||
Attribute{
|
||||
Key: "foo",
|
||||
Val: `abc"def`,
|
||||
},
|
||||
},
|
||||
Child: []*Node{
|
||||
&Node{
|
||||
Type: TextNode,
|
||||
Data: "2",
|
||||
},
|
||||
&Node{
|
||||
Type: ElementNode,
|
||||
Data: "b",
|
||||
Attr: []Attribute{
|
||||
Attribute{
|
||||
Key: "empty",
|
||||
Val: "",
|
||||
},
|
||||
},
|
||||
Child: []*Node{
|
||||
&Node{
|
||||
Type: TextNode,
|
||||
Data: "3",
|
||||
},
|
||||
},
|
||||
},
|
||||
&Node{
|
||||
Type: ElementNode,
|
||||
Data: "i",
|
||||
Attr: []Attribute{
|
||||
Attribute{
|
||||
Key: "backslash",
|
||||
Val: `\`,
|
||||
},
|
||||
},
|
||||
Child: []*Node{
|
||||
&Node{
|
||||
Type: TextNode,
|
||||
Data: "&4",
|
||||
},
|
||||
},
|
||||
},
|
||||
},
|
||||
},
|
||||
&Node{
|
||||
Type: TextNode,
|
||||
Data: "5",
|
||||
},
|
||||
&Node{
|
||||
Type: ElementNode,
|
||||
Data: "blockquote",
|
||||
},
|
||||
&Node{
|
||||
Type: ElementNode,
|
||||
Data: "br",
|
||||
},
|
||||
&Node{
|
||||
Type: TextNode,
|
||||
Data: "6",
|
||||
},
|
||||
},
|
||||
},
|
||||
},
|
||||
}
|
||||
want := `<html><head></head><body>0<1<p id="A" foo="abc"def">` +
|
||||
`2<b empty="">3</b><i backslash="\">&4</i></p>` +
|
||||
`5<blockquote></blockquote><br/>6</body></html>`
|
||||
b := new(bytes.Buffer)
|
||||
if err := Render(b, n); err != nil {
|
||||
t.Fatal(err)
|
||||
}
|
||||
if got := b.String(); got != want {
|
||||
t.Errorf("got vs want:\n%s\n%s\n", got, want)
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user