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cascadiavsgoquery

BSD-2-Clause 2 1 704
58.1 thousand (month) Feb 20 2018 Start(6 years ago)
14,116 3 3 BSD-3-Clause
Aug 29 2016 58.1 thousand (month) v1.10.0(3 months ago)

cascadia is a library for Go that provides a CSS selector engine, allowing you to use CSS selectors to select elements from an HTML document.

It is built on top of the html package in the Go standard library, and provides a more efficient and powerful way to select elements from an HTML document.

goquery brings a syntax and a set of features similar to jQuery to the Go language. goquery is a popular and easy-to-use library for Go that allows you to use a CSS selector-like syntax to select elements from an HTML document.

It is based on Go's net/html package and the CSS Selector library cascadia. Since the net/html parser returns nodes, and not a full-featured DOM tree, jQuery's stateful manipulation functions (like height(), css(), detach()) have been left off.

Also, because the net/html parser requires UTF-8 encoding, so does goquery: it is the caller's responsibility to ensure that the source document provides UTF-8 encoded HTML. See the wiki for various options to do this. Syntax-wise, it is as close as possible to jQuery, with the same function names when possible, and that warm and fuzzy chainable interface. jQuery being the ultra-popular library that it is, I felt that writing a similar HTML-manipulating library was better to follow its API than to start anew (in the same spirit as Go's fmt package), even though some of its methods are less than intuitive (looking at you, index()...).

goquery can download HTML by itself (using built-in http client) though it's not recommended for web scraping as it's likely to be blocked.

Example Use


package main

import (
  "fmt"
  "github.com/andybalholm/cascadia"
  "golang.org/x/net/html"
  "strings"
)

func main() {
  // Create an HTML string
  html := `<html>
        <body>
          <div id="content">
            <p>Hello, World!</p>
            <a href="http://example.com">Example</a>
          </div>
        </body>
      </html>`

  // Parse the HTML string into a node tree
  doc, err := html.Parse(strings.NewReader(html))
  if err != nil {
    fmt.Println("Error:", err)
    return
  }

  // Compile the CSS selector
  sel, err := cascadia.Compile("p")
  if err != nil {
    fmt.Println("Error:", err)
    return
  }

  // Use the Selector.Match method to select elements from the document
  matches := sel.Match(doc)
  if len(matches) > 0 {
    fmt.Println(matches[0].FirstChild.Data)
    // > Hello, World!
  }
}
package main

import (
  "fmt"
  "github.com/PuerkitoBio/goquery"
)

func main() {
  // Use goquery.NewDocument to load an HTML document
  // This can load from URL
  doc, err := goquery.NewDocument("http://example.com")
  // or HTML string:
  doc, err := goquery.NewDocumentFromReader("some html")
  if err != nil {
    fmt.Println("Error:", err)
    return
  }

  // Use the Selection.Find method to select elements from the document
  doc.Find("a").Each(func(i int, s *goquery.Selection) {
    // Use the Selection.Text method to get the text of the element
    fmt.Println(s.Text())
    // Use the Selection.Attr method to get the value of an attribute
    fmt.Println(s.Attr("href"))
  })
}

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