Initial Bitbucket→GitHub migration commit, based on release v2.0.0.

html.go

@@ -0,0 +1,98 @@
+/*
+	Copyright © 2014–2019 Thomas Michael Edwards. All rights reserved.
+	Use of this source code is governed by a Simplified BSD License which
+	can be found in the LICENSE file.
+*/
+
+package main
+
+import (
+	// standard packages
+	"bytes"
+	"regexp"
+	// external packages
+	"golang.org/x/net/html"
+)
+
+func getDocumentTree(source []byte) (*html.Node, error) {
+	return html.Parse(bytes.NewReader(source))
+}
+
+func getElementByID(node *html.Node, idPat string) *html.Node {
+	return getElementByIDAndTag(node, idPat, "")
+}
+
+func getElementByTag(node *html.Node, tag string) *html.Node {
+	return getElementByIDAndTag(node, "", tag)
+}
+
+func getElementByIDAndTag(node *html.Node, idPat, tag string) *html.Node {
+	if node == nil {
+		return nil
+	}
+
+	var (
+		tagOK = false
+		idOK  = false
+	)
+	if node.Type == html.ElementNode {
+		if tag == "" || tag == node.Data {
+			tagOK = true
+		}
+		if idPat == "" {
+			idOK = true
+		} else if len(node.Attr) > 0 {
+			re := regexp.MustCompile(idPat)
+			for _, attr := range node.Attr {
+				if attr.Key == "id" && re.MatchString(attr.Val) {
+					idOK = true
+				}
+			}
+		}
+		if tagOK && idOK {
+			return node
+		}
+	}
+	for child := node.FirstChild; child != nil; child = child.NextSibling {
+		if result := getElementByIDAndTag(child, idPat, tag); result != nil {
+			return result
+		}
+	}
+	return nil
+}
+
+func hasAttr(node *html.Node, attrName string) bool {
+	for _, attr := range node.Attr {
+		if attrName == attr.Key {
+			return true
+		}
+	}
+	return false
+}
+
+func hasAttrRe(node *html.Node, attrRe *regexp.Regexp) bool {
+	for _, attr := range node.Attr {
+		if attrRe.MatchString(attr.Key) {
+			return true
+		}
+	}
+	return false
+}
+
+func getAttr(node *html.Node, attrName string) *html.Attribute {
+	for _, attr := range node.Attr {
+		if attrName == attr.Key {
+			return &attr
+		}
+	}
+	return nil
+}
+
+func getAttrRe(node *html.Node, attrRe *regexp.Regexp) *html.Attribute {
+	for _, attr := range node.Attr {
+		if attrRe.MatchString(attr.Key) {
+			return &attr
+		}
+	}
+	return nil
+}