| 1 | // Copyright 2012 The Go Authors. All rights reserved. |
|---|---|
| 2 | // Use of this source code is governed by a BSD-style |
| 3 | // license that can be found in the LICENSE file. |
| 4 | |
| 5 | package present |
| 6 | |
| 7 | import ( |
| 8 | "fmt" |
| 9 | "log" |
| 10 | "net/url" |
| 11 | "strings" |
| 12 | ) |
| 13 | |
| 14 | func init() { |
| 15 | Register("link", parseLink) |
| 16 | } |
| 17 | |
| 18 | type Link struct { |
| 19 | Cmd string // original command from present source |
| 20 | URL *url.URL |
| 21 | Label string |
| 22 | } |
| 23 | |
| 24 | func (l Link) PresentCmd() string { return l.Cmd } |
| 25 | func (l Link) TemplateName() string { return "link" } |
| 26 | |
| 27 | func parseLink(ctx *Context, fileName string, lineno int, text string) (Elem, error) { |
| 28 | args := strings.Fields(text) |
| 29 | if len(args) < 2 { |
| 30 | return nil, fmt.Errorf("link element must have at least 2 arguments") |
| 31 | } |
| 32 | url, err := url.Parse(args[1]) |
| 33 | if err != nil { |
| 34 | return nil, err |
| 35 | } |
| 36 | label := "" |
| 37 | if len(args) > 2 { |
| 38 | label = strings.Join(args[2:], " ") |
| 39 | } else { |
| 40 | scheme := url.Scheme + "://" |
| 41 | if url.Scheme == "mailto" { |
| 42 | scheme = "mailto:" |
| 43 | } |
| 44 | label = strings.Replace(url.String(), scheme, "", 1) |
| 45 | } |
| 46 | return Link{text, url, label}, nil |
| 47 | } |
| 48 | |
| 49 | func renderLink(href, text string) string { |
| 50 | text = font(text) |
| 51 | if text == "" { |
| 52 | text = href |
| 53 | } |
| 54 | // Open links in new window only when their url is absolute. |
| 55 | target := "_blank" |
| 56 | if u, err := url.Parse(href); err != nil { |
| 57 | log.Println("renderLink parsing url:", err) |
| 58 | } else if !u.IsAbs() || u.Scheme == "javascript" { |
| 59 | target = "_self" |
| 60 | } |
| 61 | |
| 62 | return fmt.Sprintf(`<a href="%s" target="%s">%s</a>`, href, target, text) |
| 63 | } |
| 64 | |
| 65 | // parseInlineLink parses an inline link at the start of s, and returns |
| 66 | // a rendered HTML link and the total length of the raw inline link. |
| 67 | // If no inline link is present, it returns all zeroes. |
| 68 | func parseInlineLink(s string) (link string, length int) { |
| 69 | if !strings.HasPrefix(s, "[[") { |
| 70 | return |
| 71 | } |
| 72 | end := strings.Index(s, "]]") |
| 73 | if end == -1 { |
| 74 | return |
| 75 | } |
| 76 | urlEnd := strings.Index(s, "]") |
| 77 | rawURL := s[2:urlEnd] |
| 78 | const badURLChars = `<>"{}|\^[] ` + "`" // per RFC2396 section 2.4.3 |
| 79 | if strings.ContainsAny(rawURL, badURLChars) { |
| 80 | return |
| 81 | } |
| 82 | if urlEnd == end { |
| 83 | simpleURL := "" |
| 84 | url, err := url.Parse(rawURL) |
| 85 | if err == nil { |
| 86 | // If the URL is http://foo.com, drop the http:// |
| 87 | // In other words, render [[http://golang.org]] as: |
| 88 | // <a href="http://golang.org">golang.org</a> |
| 89 | if strings.HasPrefix(rawURL, url.Scheme+"://") { |
| 90 | simpleURL = strings.TrimPrefix(rawURL, url.Scheme+"://") |
| 91 | } else if strings.HasPrefix(rawURL, url.Scheme+":") { |
| 92 | simpleURL = strings.TrimPrefix(rawURL, url.Scheme+":") |
| 93 | } |
| 94 | } |
| 95 | return renderLink(rawURL, simpleURL), end + 2 |
| 96 | } |
| 97 | if s[urlEnd:urlEnd+2] != "][" { |
| 98 | return |
| 99 | } |
| 100 | text := s[urlEnd+2 : end] |
| 101 | return renderLink(rawURL, text), end + 2 |
| 102 | } |
| 103 |
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