Import source: parser/html

Import the existing local project snapshot. This commit organizes existing files; it does not represent newly developed functionality.

parser/html.go

@@ -0,0 +1,48 @@
+package parser
+
+import (
+	"fmt"
+	"github.com/PuerkitoBio/goquery"
+	"io"
+	"net/url"
+)
+
+// Html represents a HTML parser implementation.
+type Html struct{}
+
+// FindContent searches for the first element that satisfies the query and returns
+// its text node as content.
+func (h *Html) FindContent(r io.Reader, query string) (string, error) {
+	doc, err := goquery.NewDocumentFromReader(r)
+	if err != nil {
+		return "", fmt.Errorf("cannot parse document: %w", err)
+	}
+
+	return doc.Find(query).First().Text(), nil
+}
+
+// FindAttrMap parses HTML documents with multiple queries and retrieves the
+// corresponding attributes of found elements. All queries and related attributes
+// are stores within QueryAttrMap. All results will be stored in QueryResult.
+//
+// Example: p.FindAttrMap(body, QueryAttrMap{"div": "class"}, QueryResult{})
+func (h *Html) FindAttrMap(r io.Reader, q QueryAttrMap, res QueryResult) error {
+	doc, err := goquery.NewDocumentFromReader(r)
+	if err != nil {
+		return fmt.Errorf("cannot parse document: %w", err)
+	}
+
+	for query, attr := range q {
+		doc.Find(query).Each(func(_ int, s *goquery.Selection) {
+			val, ok := s.Attr(attr)
+			if !ok || val == "javascript:" {
+				return
+			}
+
+			val, _ = url.QueryUnescape(val)
+			res[val] = struct{}{}
+		})
+	}
+
+	return nil
+}