Does Pholcus support XPath or CSS selectors for data extraction?

Pholcus is a distributed, high-concurrency, and powerful web crawler software written in Go. It is primarily used for web scraping tasks. However, Pholcus does not directly support XPath or CSS selectors for data extraction out of the box like some other web scraping tools (e.g., Scrapy in Python). Pholcus uses query chain mode, which is more like jQuery's method of selecting elements.

The primary method of data extraction in Pholcus is through its query chain, which is somewhat similar to CSS selectors but does not provide the full functionality of CSS selectors or XPath.

Here is an example of how to use Pholcus's query chain to select elements:

// Assuming you have a response object 'ctx'
doc := ctx.GetDom()

// Extract the title using a query chain similar to jQuery
title := doc.Find("title").Text()

// Extract links using the 'A' tag
links := make([]string, 0)
doc.Find("a").Each(func(i int, s *goquery.Selection) {
    link, _ := s.Attr("href")
    links = append(links, link)
})

If you require the use of XPath or CSS selectors for web scraping in your Go projects, you might want to consider other packages like goquery for CSS selectors or htmlquery for XPath. These can be used independently or in conjunction with Pholcus for more advanced selection capabilities.

Here's an example of how you might use goquery for CSS selector-based scraping:

import (
    "github.com/PuerkitoBio/goquery"
    "net/http"
)

func main() {
    // Make a request to the website
    resp, err := http.Get("http://example.com")
    if err != nil {
        // handle error
    }
    defer resp.Body.Close()

    // Create a goquery document from the HTTP response
    document, err := goquery.NewDocumentFromReader(resp.Body)
    if err != nil {
        // handle error
    }

    // Use CSS selectors to find elements
    document.Find(".some-class").Each(func(index int, element *goquery.Selection) {
        // Extract the text or attributes
        text := element.Text()
        href, exists := element.Attr("href")
        // Do something with the extracted data
    })
}

And for htmlquery, an XPath-based scraping example would look like this:

import (
    "github.com/antchfx/htmlquery"
    "net/http"
)

func main() {
    // Make a request to the website
    resp, err := http.Get("http://example.com")
    if err != nil {
        // handle error
    }
    defer resp.Body.Close()

    // Load the HTML document
    doc, err := htmlquery.Parse(resp.Body)
    if err != nil {
        // handle error
    }

    // Use XPath to find elements
    nodes, err := htmlquery.QueryAll(doc, "//a[@class='some-class']")
    if err != nil {
        // handle error
    }
    for _, node := range nodes {
        // Extract the text or attributes
        text := htmlquery.InnerText(node)
        href := htmlquery.SelectAttr(node, "href")
        // Do something with the extracted data
    }
}

Using these packages could complement Pholcus in cases where you need finer control over element selection using CSS selectors or XPath.