webgrab

README

🌍🤏 WebGrab

WebGrab is a simple Go library which allows for easy scraping of web pages. It is built on top of the GoQuery library.

Installation

go get github.com/aljoni/webgrab

Usage

package main

import (
    "fmt"

    "github.com/aljoni/webgrab"
)

type Page struct {
    Title    string `grab:"title"`
    Body     string `grab:"body"`
    Keywords string `grab:"meta[name=keywords]" attr:"content"`
}

func main() {
    page := Page{}
    
    grabber := webgrab.New()
    grabber.Timeout = 30
    grabber.MaxRedirects = 10
    grabber.Grab("http://example.com", &page)

    fmt.Println(page.Title)
    fmt.Println(page.Body)
    fmt.Println(page.Keywords)
}

Tag Syntax

The defined tags are:

• grab:"selector" - The selector to use to grab the value.
• attr:"attribute" - The attribute of the selected element to grab.
• extract:"regexp" - A regular expression to extract a value from a string.
• filter:"regexp" - A regular expression to filter the value of a field.
• context:"selector" - Restricts the context for a nested struct or slice of structs.

The selector is a GoQuery selector. The attribute is an optional attribute of the selected element to grab. If no attribute is specified, the text of the selected element will be grabbed.

---

Arrays

If the field is an array, all matching elements will be grabbed. For example, to grab all links from a page:

type Page struct {
    Links []string `grab:"a[href]" attr:"href"`
}

---

Nested Structs and Context Windows

You can use nested structs to grab values from a specific section of the page.
With the new context tag, you can restrict the scraping context for a struct or a slice of structs.

Single Nested Struct with Context

type Profile struct {
    Name  string `grab:".name"`
    Email string `grab:".email"`
}

type Page struct {
    Profile Profile `context:".profile-section"`
}

This will only search for .name and .email inside the first .profile-section element.

Slice of Structs with Context

type Item struct {
    Title string `grab:".title"`
    Link  string `grab:"a" attr:"href"`
}

type Page struct {
    Items []Item `context:".item"`
}

This will find all elements matching .item, and for each, scrape the .title and the first <a>'s href inside that .item.

---

Extract

The extract tag can be used to extract a value from a string using a regular expression. For example, to extract the title from a Wikipedia page:

type Page struct {
    Title string `grab:"title" extract:"(.+) - Wikipedia"`
}

---

Filter

The filter tag can be used to filter the value of a field. For example, to get all links that end with .html:

type Page struct {
    Links []string `grab:"a[href]" attr:"href" filter:".*\\.html$"`
}

Documentation

Index

• type Grabber
  • func New() *Grabber
  • func (g Grabber) Grab(url string, data any) error

Types

type Grabber

type Grabber struct {
	Timeout      int
	MaxRedirects int
	UserAgent    string
}

Grabber configures and performs web scraping.

func New

func New() *Grabber

New returns a new Grabber with default values.

func (Grabber) Grab

func (g Grabber) Grab(url string, data any) error

Grab fetches and populates data from a URL into the provided struct pointer.