gogoquery

How to find out if selector is at first or last position

I use goquery's function .Each() to recurse into the child elements. Is there a way to find out if this is the first (or last) child of a parent? I try to remove starting and trailing whitespace of HTML nodes. Checking for the first child is probably a matter of testing i == 0. But what about the last child element?

This is my code so far:

package main

import (
    "fmt"
    "io"
    "os"
    "strings"

    "github.com/PuerkitoBio/goquery"
)

// recursive function
func dumpElement(i int, sel *goquery.Selection) {
    fmt.Println("dump Element - is this the first or last element? I don't know")
    sel.Contents().Each(dumpElement)
}

func startRecursion(r io.Reader) error {
    g, err := goquery.NewDocumentFromReader(r)
    if err != nil {
        return err
    }

    g.Find(":root > body").Each(dumpElement)
    return nil
}

func main() {
    doc := `<!DOCTYPE html>
    <html><head><title>foo</title></head><body>
    <div class="bla">foo <b> bar </b> baz</div>
    </body></html>`

    if err := startRecursion(strings.NewReader(doc)); err != nil {
        os.Exit(-1)
    }
}
Solution

  • Most likely you'd have to write a function that returns the funciton you are using, so you get access to the original selections length, something like:

    type iterator func(int, *goquery.Selection)

func dumpElementFrom(s *goquery.Selection) iterator {
    lastIndex := s.Size() - 1
    return func(i int, sel *goquery.Selection) {
        if i == lastIndex {
            fmt.Println("Last Element")
        }
        sel.Contents().Each(dumpElement)
    }
}


func startRecursion(r io.Reader) error {
    g, err := goquery.NewDocumentFromReader(r)
    if err != nil {
        return err
    }

    g.Find(":root > body").Each(dumpElementFrom(g))
    return nil
}