| // Copyright 2012 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package present |
| |
| import ( |
| "fmt" |
| "html/template" |
| "net/url" |
| "strings" |
| ) |
| |
| func init() { |
| Register("link", parseLink, link) |
| } |
| |
| type Link struct { |
| URL *url.URL |
| Args []string |
| } |
| |
| func (l Link) HTML(t *template.Template) (template.HTML, error) { |
| return execTemplate(t, "link", l) |
| } |
| |
| func parseLink(fileName string, lineno int, text string) (Elem, error) { |
| args := strings.Fields(text) |
| url, err := url.Parse(args[1]) |
| if err != nil { |
| return nil, err |
| } |
| return Link{url, args[2:]}, nil |
| } |
| |
| // link is the entry point for the '.link' present command. |
| func link(url url.URL, arg []string) (template.HTML, error) { |
| label := "" |
| switch len(arg) { |
| case 0: |
| scheme := url.Scheme + "://" |
| if url.Scheme == "mailto" { |
| scheme = "mailto:" |
| } |
| label = strings.Replace(url.String(), scheme, "", 1) |
| default: |
| label = strings.Join(arg, " ") |
| } |
| return template.HTML(renderLink(url.String(), label)), nil |
| } |
| |
| func renderLink(url, text string) string { |
| text = font(text) |
| if text == "" { |
| text = url |
| } |
| return fmt.Sprintf(`<a href="%s" target="_blank">%s</a>`, url, text) |
| } |
| |
| // parseInlineLink parses an inline link at the start of s, and returns |
| // a rendered HTML link and the total length of the raw inline link. |
| // If no inline link is present, it returns all zeroes. |
| func parseInlineLink(s string) (link string, length int) { |
| if len(s) < 2 || s[:2] != "[[" { |
| return |
| } |
| end := strings.Index(s, "]]") |
| if end == -1 { |
| return |
| } |
| urlEnd := strings.Index(s, "]") |
| url := s[2:urlEnd] |
| const badURLChars = `<>"{}|\^~[] ` + "`" // per RFC1738 section 2.2 |
| if strings.ContainsAny(url, badURLChars) { |
| return |
| } |
| if urlEnd == end { |
| return renderLink(url, ""), end + 2 |
| } |
| if s[urlEnd:urlEnd+2] != "][" { |
| return |
| } |
| text := s[urlEnd+2 : end] |
| return renderLink(url, text), end + 2 |
| } |