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.
You can use TracLinks in:
and any other text fields explicitly marked as supporting WikiFormatting.
Some examples:
Display:
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: 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: 1
wiki is the default if the namespace part of a full link is omitted (since version 0.10):
[SandBox the sandbox]
Display: 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.
To create a link to a specific anchor in a page, use '#':
[#Relativelinks relative links]
Displays:
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 '../':
[../Sibling see next sibling]
(Changed in 0.11) Note that in Trac 0.10, using e.g. [../newticket] may have worked for linking to the /newticket top-level URL, but now in 0.11 it will stay in the wiki namespace and link to a sibling page. See #Server-relativelinks for the new syntax.
Other prefixes can be defined freely and made to point to resources in other Web applications. The definition of those prefixes as well as the URLs of the corresponding Web applications is defined in a special Wiki page, the InterMapTxt page. Note that while this could be used to create links to other Trac environments, there's a more specialized way to register other Trac environments which offers greater flexibility.
This can be seen as a kind of InterWiki link specialized for targeting other Trac projects.
Any type of Trac links could be written in one Trac environment and actually refer to resources present in another Trac environment, provided the Trac link is prefixed by the name of that other Trac environment followed by a colon. That other Trac environment must be registered, under its name or an alias. See InterTrac for details.
A distinctive advantage of InterTrac links over InterWiki links is that the shorthand form of Trac links usually have a way to understand the InterTrac prefixes. For example, links to Trac tickets can be written #T234 (if T was set as an alias for Trac), links to Trac changesets can be written [trac 1508].
It is often useful to be able to link to objects in your project that have no built-in Trac linking mechanism, such as static resources, newticket, a shared /register page on the server, etc.
To link to resources inside the project, use either an absolute path from the project root, or a relative link from the URL of the current page (Changed in 0.11):
[/newticket Create a new ticket] [/ home]
Display: newticket? home
To link to another location on the server (outside the project), use the 'location' link syntax (Changed in 0.11):
[//register Register Here]
Display: Register Here
Immediately after a TracLinks prefix, targets containing space characters should be enclosed in a pair of quotes or double quotes. Examples:
To prevent parsing of a TracLink, you can escape it by preceding it with a '!' (exclamation mark).
!NoLinkHere. ![42] is not a link either.
Display:
NoLinkHere. [42] is not a link either.
The Trac links target Trac resources which have generally more than one way to be rendered, according to some extra parameters. For example, a Wiki page can accept a version or a format parameter, a report can make use of dynamic variables, etc.
Any Trac links can support an arbitrary set of parameters, written in the same way as they would be for the corresponding URL. Some examples:
The following sections describe the individual link types in detail, as well as several notes advanced usage of links.
The link syntax for attachments is as follows:
See TracQuery#UsingTracLinks and #ticket:links.
Besides the obvious ticket:id form, it is also possible to specify a list of tickets or even a range of tickets instead of the id. This generates a link to a custom query view containing this fixed set of tickets.
Example:
(since Trac 0.11)
Links to the timeline can be created by specifying a date in the ISO:8601 format. The date can be optionally followed by a time specification. The time is interpreted as being UTC time, but alternatively you can specify your local time, followed by your timezone if you don't want to compute the UTC time.
Examples:
(since Trac 0.11)
See WikiPageNames and quoting space in TracLinks above.
The default behavior for a source:/some/path link is to open the directory browser if the path points to a directory and otherwise open the log view.
It's also possible to link directly to a specific revision of a file like this:
If the revision is specified, one can even link to a specific line number:
Finally, one can also highlight an arbitrary set of lines:
(since 0.11)
To force the download of a file in the repository, as opposed to displaying it in the browser, use the export link. Several forms are available:
This can be very useful for displaying HTML documentation with correct stylesheets and images, in case that has been checked in the repository.
If the path is to a directory in the repository instead of a specific file, the source browser will be used to display the directory (identical to the result of source:/some/dir.
The log: links are used to display revision ranges. In its simplest form, it can link to the latest revisions from the specified path, but it can also support displaying an arbitrary set of revisions.
There are short forms for revision ranges as well:
Finally, note that in all of the above, a revision range can be written indifferently x:y or x-y.
See also: WikiFormatting, TracWiki, WikiPageNames, InterTrac, InterWiki