109 lines
2.8 KiB
Go
109 lines
2.8 KiB
Go
// gomuks - A terminal Matrix client written in Go.
|
|
// Copyright (C) 2018 Tulir Asokan
|
|
//
|
|
// This program is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// This program is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU General Public License
|
|
// along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
package htmlparser
|
|
|
|
import (
|
|
"io"
|
|
"strings"
|
|
|
|
"golang.org/x/net/html"
|
|
)
|
|
|
|
type HTMLProcessor interface {
|
|
Preprocess()
|
|
HandleStartTag(tagName string, attrs map[string]string)
|
|
HandleSelfClosingTag(tagName string, attrs map[string]string)
|
|
HandleText(text string)
|
|
HandleEndTag(tagName string)
|
|
ReceiveError(err error)
|
|
Postprocess()
|
|
}
|
|
|
|
type HTMLParser struct {
|
|
*html.Tokenizer
|
|
processor HTMLProcessor
|
|
}
|
|
|
|
func NewHTMLParserFromTokenizer(z *html.Tokenizer, processor HTMLProcessor) HTMLParser {
|
|
return HTMLParser{
|
|
z,
|
|
processor,
|
|
}
|
|
}
|
|
|
|
func NewHTMLParserFromReader(reader io.Reader, processor HTMLProcessor) HTMLParser {
|
|
return NewHTMLParserFromTokenizer(html.NewTokenizer(reader), processor)
|
|
}
|
|
|
|
func NewHTMLParserFromString(html string, processor HTMLProcessor) HTMLParser {
|
|
return NewHTMLParserFromReader(strings.NewReader(html), processor)
|
|
}
|
|
|
|
var SelfClosingTags = []string{"img", "br", "hr", "area", "base", "basefont", "input", "link", "meta"}
|
|
|
|
func (parser HTMLParser) mapAttrs() map[string]string {
|
|
attrs := make(map[string]string)
|
|
hasMore := true
|
|
for hasMore {
|
|
var key, val []byte
|
|
key, val, hasMore = parser.TagAttr()
|
|
attrs[string(key)] = string(val)
|
|
}
|
|
return attrs
|
|
}
|
|
|
|
func (parser HTMLParser) isSelfClosing(tag string) bool {
|
|
for _, selfClosingTag := range SelfClosingTags {
|
|
if tag == selfClosingTag {
|
|
return true
|
|
}
|
|
}
|
|
return false
|
|
}
|
|
|
|
func (parser HTMLParser) Process() {
|
|
parser.processor.Preprocess()
|
|
Loop:
|
|
for {
|
|
tt := parser.Next()
|
|
switch tt {
|
|
case html.ErrorToken:
|
|
parser.processor.ReceiveError(parser.Err())
|
|
break Loop
|
|
case html.TextToken:
|
|
parser.processor.HandleText(string(parser.Text()))
|
|
case html.StartTagToken, html.SelfClosingTagToken:
|
|
tagb, _ := parser.TagName()
|
|
attrs := parser.mapAttrs()
|
|
tag := string(tagb)
|
|
|
|
selfClosing := tt == html.SelfClosingTagToken || parser.isSelfClosing(tag)
|
|
|
|
if selfClosing {
|
|
parser.processor.HandleSelfClosingTag(tag, attrs)
|
|
} else {
|
|
parser.processor.HandleStartTag(tag, attrs)
|
|
}
|
|
case html.EndTagToken:
|
|
tagb, _ := parser.TagName()
|
|
parser.processor.HandleEndTag(string(tagb))
|
|
}
|
|
}
|
|
|
|
parser.processor.Postprocess()
|
|
}
|