services/rss/parser/parser.go

package parser

import (
	"errors"
	"net/http"
	"net/url"

	"github.com/PuerkitoBio/goquery"
)

var (
	parsers = map[string]Parser{
		"a16z.com":     a16zParser,
		"cnbc.com":     cnbcParser,
		"www.cnbc.com": cnbcParser,
	}
)

type Parser func(string) (string, error)

func Parse(uri string) (string, error) {
	u, err := url.Parse(uri)
	if err != nil {
		return "", err
	}

	if v, ok := parsers[u.Host]; ok {
		return v(uri)
	}
	return "", errors.New("no parser for url")
}

func classParser(class string) Parser {
	return func(url string) (string, error) {
		// Request the HTML page.
		res, err := http.Get(url)
		if err != nil {
			return "", err
		}

		defer res.Body.Close()

		if res.StatusCode != 200 {
			return "", errors.New("bad status code")
		}

		// Load the HTML document
		doc, err := goquery.NewDocumentFromReader(res.Body)
		if err != nil {
			return "", err
		}

		return doc.Find(class).Html()
	}
}

func a16zParser(url string) (string, error) {
	return classParser(".blog-content")(url)
}

func cnbcParser(url string) (string, error) {
	return classParser(".PageBuilder-col-9")(url)
}