func render1()

in html/render.go [68:232]
153 lines of code
57 McCabe index (conditional complexity)

func render1(w writer, n *Node) error {
	// Render non-element nodes; these are the easy cases.
	switch n.Type {
	case ErrorNode:
		return errors.New("html: cannot render an ErrorNode node")
	case TextNode:
		return escape(w, n.Data)
	case DocumentNode:
		for c := n.FirstChild; c != nil; c = c.NextSibling {
			if err := render1(w, c); err != nil {
				return err
			}
		}
		return nil
	case ElementNode:
		// No-op.
	case CommentNode:
		if _, err := w.WriteString("<!--"); err != nil {
			return err
		}
		if _, err := w.WriteString(n.Data); err != nil {
			return err
		}
		if _, err := w.WriteString("-->"); err != nil {
			return err
		}
		return nil
	case DoctypeNode:
		if _, err := w.WriteString("<!DOCTYPE "); err != nil {
			return err
		}
		if _, err := w.WriteString(n.Data); err != nil {
			return err
		}
		if n.Attr != nil {
			var p, s string
			for _, a := range n.Attr {
				switch a.Key {
				case "public":
					p = a.Val
				case "system":
					s = a.Val
				}
			}
			if p != "" {
				if _, err := w.WriteString(" PUBLIC "); err != nil {
					return err
				}
				if err := writeQuoted(w, p); err != nil {
					return err
				}
				if s != "" {
					if err := w.WriteByte(' '); err != nil {
						return err
					}
					if err := writeQuoted(w, s); err != nil {
						return err
					}
				}
			} else if s != "" {
				if _, err := w.WriteString(" SYSTEM "); err != nil {
					return err
				}
				if err := writeQuoted(w, s); err != nil {
					return err
				}
			}
		}
		return w.WriteByte('>')
	case RawNode:
		_, err := w.WriteString(n.Data)
		return err
	default:
		return errors.New("html: unknown node type")
	}

	// Render the <xxx> opening tag.
	if err := w.WriteByte('<'); err != nil {
		return err
	}
	if _, err := w.WriteString(n.Data); err != nil {
		return err
	}
	for _, a := range n.Attr {
		if err := w.WriteByte(' '); err != nil {
			return err
		}
		if a.Namespace != "" {
			if _, err := w.WriteString(a.Namespace); err != nil {
				return err
			}
			if err := w.WriteByte(':'); err != nil {
				return err
			}
		}
		if _, err := w.WriteString(a.Key); err != nil {
			return err
		}
		if _, err := w.WriteString(`="`); err != nil {
			return err
		}
		if err := escape(w, a.Val); err != nil {
			return err
		}
		if err := w.WriteByte('"'); err != nil {
			return err
		}
	}
	if voidElements[n.Data] {
		if n.FirstChild != nil {
			return fmt.Errorf("html: void element <%s> has child nodes", n.Data)
		}
		_, err := w.WriteString("/>")
		return err
	}
	if err := w.WriteByte('>'); err != nil {
		return err
	}

	// Add initial newline where there is danger of a newline beging ignored.
	if c := n.FirstChild; c != nil && c.Type == TextNode && strings.HasPrefix(c.Data, "\n") {
		switch n.Data {
		case "pre", "listing", "textarea":
			if err := w.WriteByte('\n'); err != nil {
				return err
			}
		}
	}

	// Render any child nodes.
	switch n.Data {
	case "iframe", "noembed", "noframes", "noscript", "plaintext", "script", "style", "xmp":
		for c := n.FirstChild; c != nil; c = c.NextSibling {
			if c.Type == TextNode {
				if _, err := w.WriteString(c.Data); err != nil {
					return err
				}
			} else {
				if err := render1(w, c); err != nil {
					return err
				}
			}
		}
		if n.Data == "plaintext" {
			// Don't render anything else. <plaintext> must be the
			// last element in the file, with no closing tag.
			return plaintextAbort
		}
	default:
		for c := n.FirstChild; c != nil; c = c.NextSibling {
			if err := render1(w, c); err != nil {
				return err
			}
		}
	}

	// Render the </xxx> closing tag.
	if _, err := w.WriteString("</"); err != nil {
		return err
	}
	if _, err := w.WriteString(n.Data); err != nil {
		return err
	}
	return w.WriteByte('>')
}