README
¶
Pagser
Pagser inspired by page parser。
Pagser is an simple, easy, extensible, configurable HTML deserialization to struct based on goquery and struct tags, It's parser library from scrago.
Features
- Simple - Use golang struct tag syntax.
- Easy - Easy use for your spider/crawler/colly application.
- Extensible - Support for extension functions.
- Struct tag grammar - Grammar is simple, like `pagser:"a->attr(href)"`.
- Nested Structure - Support Nested Structure for node.
- Configurable - Support configuration.
- GoQuery/Colly - Support all goquery project, such as go-colly.
Install
go get github.com/foolin/pagser
Docs
See Pagser
Usage
package main
import (
"encoding/json"
"fmt"
"github.com/foolin/pagser"
)
const rawPageHtml = `
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Pagser Title</title>
</head>
<body>
<h1>H1 Pagser Example</h1>
<div class="navlink">
<div class="container">
<ul class="clearfix">
<li id=''><a href="/">Index</a></li>
<li id='2'><a href="/list/web" title="web site">Web page</a></li>
<li id='3'><a href="/list/pc" title="pc page">Pc Page</a></li>
<li id='4'><a href="/list/mobile" title="mobile page">Mobile Page</a></li>
</ul>
</div>
</div>
</body>
</html>
`
type ExampPage struct {
Title string `pagser:"title"`
H1 string `pagser:"h1"`
Navs []struct {
ID int `pagser:"->attrInt(id, -1)"`
Name string `pagser:"a->attr(href)"`
Url string `pagser:"a"`
} `pagser:".navlink li"`
}
func main() {
//New default config
p := pagser.New()
//data parser model
var page ExampPage
//parse html data
err := p.Parse(&page, rawPageHtml)
//check error
if err != nil {
panic(err)
}
//print data
fmt.Printf("Page data json: \n-------------\n%v\n-------------\n", toJson(page))
}
func toJson(v interface{}) string {
data, _ := json.MarshalIndent(v, "", "\t")
return string(data)
}
Run output:
Page data json:
-------------
{
"Title": "Pagser Title",
"H1": "H1 Pagser Example",
"Navs": [
{
"ID": -1,
"Name": "/",
"Url": "Index"
},
{
"ID": 2,
"Name": "/list/web",
"Url": "Web page"
},
{
"ID": 3,
"Name": "/list/pc",
"Url": "Pc Page"
},
{
"ID": 4,
"Name": "/list/mobile",
"Url": "Mobile Page"
}
]
}
-------------
Configuration
type Config struct {
TagerName string //struct tag name, default is `pagser`
FuncSymbol string //Function symbol, default is `->`
IgnoreSymbol string //Ignore symbol, default is `-`
Debug bool //Debug mode, debug will print some log, default is `false`
}
Struct tag grammar
[goquery selector]->[function]
Example:
type ExamData struct {
Herf string `pagser:".navLink li a->attr(href)"`
}
1.Struct tag name:
pagser
2.goquery selector:.navLink li a
3.Function symbol:->
4.Function name:attr
5.Function arguments:href
Functions
Builtin functions
- html()
- text()
- attr(name)
- attrInt(name, defaultValue) //covert attr value to int
- outerHtml()
- value(name) //alias for
goquery.AttrOr("value", "")
Extensions functions
- Markdown() //convert html to markdown format.
- UgcHtml() //sanitize html
Extensions function need register, like:
import "github.com/foolin/pagser/extensions/markdown"
p := pagser.New()
//Register Markdown
markdown.Register(p)
Write my function
Function interface
type CallFunc func(node *goquery.Selection, args ...string) (out interface{}, err error)
1. Write global function:
//global function need call pagser.RegisterFunc("myAttrInt", myAttrInt) before use it.
func myAttrInt(node *goquery.Selection, args ...string) (out interface{}, err error) {
if len(args) < 2 {
return "", fmt.Errorf("attrInt(name,defaultValue) must has name and default value, eg: attrInt(id,-1)")
}
name := args[0]
defaultValue := args[1]
attrVal := node.AttrOr(name, defaultValue)
outVal, err := strconv.Atoi(attrVal)
if err != nil {
return strconv.Atoi(defaultValue)
}
return outVal, nil
}
type MyStruct struct{
Attr int `pagser:"->myAttrInt(id, -1)"`
}
func main(){
p := pagser.New()
//Register AttrInt
p.RegisterFunc("myAttrInt", myAttrInt)
//Todo
//data parser model
var page MyStruct
//parse html data
err := p.Parse(&page, rawPageHtml)
//...
}
2. Write struct function:
type MyStruct struct{
Attr int `pagser:"->myAttrInt(id, -1)"`
}
//Struct function not need register.
func (s MyStruct) myAttrInt(node *goquery.Selection, args ...string) (out interface{}, err error) {
if len(args) < 2 {
return "", fmt.Errorf("attrInt(name,defaultValue) must has name and default value, eg: attrInt(id,-1)")
}
name := args[0]
defaultValue := args[1]
attrVal := node.AttrOr(name, defaultValue)
outVal, err := strconv.At
oi(attrVal)
if err != nil {
return strconv.Atoi(defaultValue)
}
return outVal, nil
}
func main(){
p := pagser.New()
//Todo
//data parser model
var page MyStruct
//parse html data
err := p.Parse(&page, rawPageHtml)
//...
}
Colly Example
Work with colly:
p := pagser.New()
// On every a element which has href attribute call callback
collector.OnHTML("body", func(e *colly.HTMLElement) {
//data parser model
var page MyStruct
//parse html data
err := p.ParseSelection(&page, e.Dom)
})
Example
Dependences
- github.com/PuerkitoBio/goquery
- github.com/spf13/cast
- github.com/mattn/godown
- github.com/microcosm-cc/bluemonday
Documentation
¶
Index ¶
- type CallFunc
- type Config
- type Pagser
- func (p *Pagser) Parse(v interface{}, document string) (err error)
- func (p *Pagser) ParseDocument(v interface{}, document *goquery.Document) (err error)
- func (p *Pagser) ParseSelection(v interface{}, selection *goquery.Selection) (err error)
- func (p *Pagser) RegisterFunc(name string, fn CallFunc) error
- type Tager
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Config ¶
type Config struct {
TagerName string //struct tag name, default is `pagser`
FuncSymbol string //Function symbol, default is `->`
IgnoreSymbol string //Ignore symbol, default is `-`
Debug bool //Debug mode, debug will print some log, default is `false`
}
func DefaultConfig ¶
func DefaultConfig() Config
type Pagser ¶
type Pagser struct {
// contains filtered or unexported fields
}
func MustNewWithConfig ¶
func NewWithConfig ¶
func (*Pagser) ParseDocument ¶
func (*Pagser) ParseSelection ¶
Source Files
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