= Trac Links =
[[TracGuideToc]]

TracLinks are a fundamental feature of Trac, because they allow easy hyperlinking between the various entities in the system—such as tickets, reports, changesets, Wiki pages, milestones, and source files—from anywhere WikiFormatting is used.

TracLinks are generally of the form '''type:id''' (where ''id'' represents the
number, name or path of the item) though some frequently used kinds of items
also have short-hand notations.

== Where to use TracLinks ==
You can use TracLinks in:

 * Source code (Subversion) commit messages
 * Wiki pages
 * Full descriptions for tickets, reports and milestones

and any other text fields explicitly marked as supporting WikiFormatting.

Some examples:
 * Tickets: '''!#1''' or '''!ticket:1'''
 * Ticket comments: '''!comment:ticket:1:2''' 
 * Reports: '''!{1}''' or '''!report:1'''
 * Changesets: '''!r1''', '''![1]''', '''!changeset:1''' or (restricted) '''![1/trunk]''', '''!changeset:1/trunk''', '''![2:5/trunk]'''
 * Revision log: '''!r1:3''', '''![1:3]''' or '''!log:@1:3''', '''!log:trunk@1:3'''
 * Diffs (requires [milestone:0.10 0.10]): '''!diff:@1:3''', '''!diff:tags/trac-0.9.2/wiki-default//tags/trac-0.9.3/wiki-default''' or '''!diff:trunk/trac@3538//sandbox/vc-refactoring@3539'''
 * Wiki pages: '''!CamelCase''' or '''!wiki:CamelCase'''
 * Parent page: '''![..]'''
 * Milestones: '''!milestone:1.0'''
 * Attachment: '''!attachment:ticket:944:attachment.1073.diff'''
 * Files: '''!source:trunk/COPYING'''
 * A specific file revision: '''!source:/trunk/COPYING@200'''
 * A particular line of a specific file revision: '''!source:/trunk/COPYING@200#L25'''
Display:
 * Tickets: #1 or ticket:1
 * Ticket comments: comment:ticket:1:2 
 * Reports: {1} or report:1
 * Changesets: r1, [1], changeset:1, or (restricted) [1/trunk], changeset:1/trunk, [2:5/trunk]
 * Revision log: r1:3, [1:3] or log:@1:3, log:trunk@1:3
 * Diffs (requires [milestone:0.10 0.10]): diff:@20:30, diff:tags/trac-0.9.2/wiki-default//tags/trac-0.9.3/wiki-default or diff:trunk/trac@3538//sandbox/vc-refactoring/trac@3539
 * Wiki pages: CamelCase or wiki:CamelCase
 * Parent page: '''[..]'''
 * Milestones: milestone:1.0
 * Attachment: attachment:ticket:944:attachment.1073.diff
 * Files: source:trunk/COPYING
 * A specific file revision: source:/trunk/COPYING@200
 * A particular line of a specific file revision: source:/trunk/COPYING@200#L25

'''Note:''' The wiki:CamelCase form is rarely used, but it can be convenient to refer to
pages whose names do not follow WikiPageNames rules, i.e., single words,
non-alphabetic characters, etc. See WikiPageNames for more about features specific
to links to Wiki page names.

Trac links using the full (non-shorthand) notation can also be given a custom
link title like this:

{{{
[ticket:1 This is a link to ticket number one].
}}}

Display: [ticket:1 This is a link to ticket number one].

If the title is omitted, only the id (the part after the colon) is displayed:

{{{
[ticket:1]
}}}

Display: [ticket:1]

`wiki` is the default if the namespace part of a full link is omitted (''since version 0.10''):

{{{
[SandBox the sandbox]
}}}

Display: [SandBox the sandbox]

TracLinks are a very simple idea, but actually allow quite a complex network of information. In practice, it's very intuitive and simple to use, and we've found the "link trail" extremely helpful to better understand what's happening in a project or why a particular change was made.


== Advanced use of TracLinks ==

=== Relative links ===

To create a link to a specific anchor in a page, use '#':
{{{
 [#Relativelinks relative links]
}}}
Displays:
  [#Relativelinks relative links]

Hint: when you move your mouse over the title of a section, a '¶' character will be displayed. This is a link to that specific section and you can use this to copy the `#...` part inside a relative link to an anchor.

To create a link to a SubWiki-page just use a '/':
{{{
 WikiPage/SubWikiPage or ./SubWikiPage
}}}

To link from a SubWiki page to a parent, simply use a '..':
{{{
  [..]
}}}

To link from a SubWiki page to a sibling page, use a '../