内容简介：最近要用然后我花了两天时间撸出了有个
最近要用 golang
写一个需要解析 HTML
的项目，到网上找了一个库叫 goquery
。虽然它的 API
挺不错， css selector
基本上也全支持了，但写这种代码果然还是有点无聊，于是我就想，为什么不能跟 go
的 json
库和 xml
库一样，直接 Unmarshal(HTML)
呢？
然后我花了两天时间撸出了 unhtml
-> Github 传送门
样例 & 性能
有个 HTML
var AllTypeHTML = []byte(`
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
<div id="test">
<ul>
<li>0</li>
<li>1</li>
<li>2</li>
<li>3</li>
</ul>
<div>
<p>Hexilee</p>
<p>20</p>
<p>true</p>
</div>
<p>Hello World!</p>
<p>10</p>
<p>3.14</p>
<p>true</p>
</div>
</body>
</html>
`)
如果你想把它解析为一个结构体
package example
type (
PartTypesStruct struct {
Slice []int
Struct TestUser
String string
Int int
Float64 float64
Bool bool
}
TestUser struct {
Name string
Age uint
LikeLemon bool
}
)
直接用 goquery
要这样写
package example
import (
"bytes"
"github.com/PuerkitoBio/goquery"
"strconv"
)
func parsePartTypesLogically() (PartTypesStruct, error) {
doc, err := goquery.NewDocumentFromReader(bytes.NewReader(AllTypeHTML))
partTypes := PartTypesStruct{}
if err == nil {
selection := doc.Find(partTypes.Root())
partTypes.Slice = make([]int, 0)
selection.Find(`ul > li`).Each(func(i int, selection *goquery.Selection) {
Int, parseErr := strconv.Atoi(selection.Text())
if parseErr != nil {
err = parseErr
}
partTypes.Slice = append(partTypes.Slice, Int)
})
if err == nil {
partTypes.Struct.Name = selection.Find(`#test > div > p:nth-child(1)`).Text()
Int, parseErr := strconv.Atoi(selection.Find(`#test > div > p:nth-child(2)`).Text())
if err = parseErr; err == nil {
partTypes.Struct.Age = uint(Int)
Bool, parseErr := strconv.ParseBool(selection.Find(`#test > div > p:nth-child(3)`).Text())
if err = parseErr; err == nil {
partTypes.Struct.LikeLemon = Bool
String := selection.Find(`#test > p:nth-child(3)`).Text()
Int, parseErr := strconv.Atoi(selection.Find(`#test > p:nth-child(4)`).Text())
if err = parseErr; err != nil {
return partTypes, err
}
Float64, parseErr := strconv.ParseFloat(selection.Find(`#test > p:nth-child(5)`).Text(), 0)
if err = parseErr; err != nil {
return partTypes, err
}
Bool, parseErr := strconv.ParseBool(selection.Find(`#test > p:nth-child(6)`).Text())
if err = parseErr; err != nil {
return partTypes, err
}
partTypes.String = String
partTypes.Int = Int
partTypes.Float64 = Float64
partTypes.Bool = Bool
}
}
}
}
return partTypes, err
}
写得很难受
而现在你只要这么写
package main
import (
"encoding/json"
"fmt"
"github.com/Hexilee/unhtml"
"io/ioutil"
)
type (
PartTypesStruct struct {
Slice []int `html:"ul > li"`
Struct TestUser `html:"#test > div"`
String string `html:"#test > p:nth-child(3)"`
Int int `html:"#test > p:nth-child(4)"`
Float64 float64 `html:"#test > p:nth-child(5)"`
Bool bool `html:"#test > p:nth-child(6)"`
}
TestUser struct {
Name string `html:"p:nth-child(1)"`
Age uint `html:"p:nth-child(2)"`
LikeLemon bool `html:"p:nth-child(3)"`
}
)
func (PartTypesStruct) Root() string {
return "#test"
}
func main() {
allTypes := PartTypesStruct{}
_ := unhtml.Unmarshal(AllTypeHTML, &allTypes)
result, _ := json.Marshal(&allTypes)
fmt.Println(string(result))
}
就能得到结果
{
"Slice": [
0,
1,
2,
3
],
"Struct": {
"Name": "Hexilee",
"Age": 20,
"LikeLemon": true
},
"String": "Hello World!",
"Int": 10,
"Float64": 3.14,
"Bool": true
}
开发效率大大提升！但毫无疑问用了大量反射，让人担心它的运行效率。于是我写了两个 Benchmarks
func BenchmarkUnmarshalPartTypes(b *testing.B) {
assert.NotNil(b, AllTypeHTML)
for i := 0; i < b.N; i++ {
partTypes := PartTypesStruct{}
assert.Nil(b, Unmarshal(AllTypeHTML, &partTypes))
}
}
func BenchmarkParsePartTypesLogically(b *testing.B) {
assert.NotNil(b, AllTypeHTML)
for i := 0; i < b.N; i++ {
_, err := parsePartTypesLogically()
assert.Nil(b, err)
}
}
测试结果：
> go test -bench=. goos: darwin goarch: amd64 pkg: github.com/Hexilee/unhtml BenchmarkUnmarshalPartTypes-4 30000 54096 ns/op BenchmarkParsePartTypesLogically-4 30000 45188 ns/op PASS ok github.com/Hexilee/unhtml 4.098s
运行效率稍微低些，但这只是展示和测试用的 HTML
，在解析实际中更复杂的 HTML
时两者的运行效率是十分接近的。
一些注意事项和特性请看 README
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持 码农网
猜你喜欢:
本站部分资源来源于网络，本站转载出于传递更多信息之目的，版权归原作者或者来源机构所有，如转载稿涉及版权问题，请联系我们。
XML Hacks
Michael Fitzgerald / O'Reilly Media, Inc. / 2004-07-27 / USD 24.95
Developers and system administrators alike are uncovering the true power of XML, the Extensible Markup Language that enables data to be sent over the Internet from one computer platform to another or ......一起来看看 《XML Hacks》 这本书的介绍吧!
