Snippets

Whether you are coding or writing the next vampire best-seller, you’re likely to need certain short fragments of text again and again. Use snippets to save yourself tedious typing. Snippets are smart templates that will insert text for you and adapt it to their context.

To create a new snippet, select Tools | New Snippet... Sublime Text will present you with a skeleton for it.

Snippets can be stored under any package’s folder, but to keep it simple while you’re learning, you can save them to your Packages/User folder.

Snippets File Format

Snippets typically live in a Sublime Text package. They are simplified XML files with the extension .sublime-snippet. For instance, you could have a greeting.sublime-snippet inside an Email package.

The structure of a typical snippet is as follows (including the default hints Sublime Text inserts for your convenience):

<snippet>
    <content><![CDATA[Type your snippet here]]></content>
    <!-- Optional: Tab trigger to activate the snippet -->
    <tabTrigger>xyzzy</tabTrigger>
    <!-- Optional: Scope the tab trigger will be active in -->
    <scope>source.python</scope>
    <!-- Optional: Description to show in the menu -->
    <description>My Fancy Snippet</description>
</snippet>

The snippet element contains all the information Sublime Text needs in order to know what to insert, whether to insert and when. Let’s see all of these parts in turn.

content

The actual snippet. Snippets can range from simple to fairly complex templates. We’ll look at examples of both later.

Keep the following in mind when writing your own snippets:

  • If you want to get a literal $, you have to escape it like this: \$.
  • When writing a snippet that contains indentation, always use tabs. When the snippet is inserted, the tabs will be transformed into spaces if the option translateTabsToSpaces is true.
  • The content must be included in a <![CDATA[...]]> section. Snippets won’t work if you don’t do this!
  • The content of your snippet must not contain ]]> because this string of characters will prematurely close the <![CDATA[???]]> section, resulting in an XML error. To work around this pitfall, you can insert an undefined variable into the string like this: ]]$NOT_DEFINED>. This modified string passes through the XML parser without closing the content element’s <![CDATA[???]]> section, but Sublime Text will replace $NOT_DEFINED with an empty string before inserting the snippet into your file. In other words, ]]$NOT_DEFINED> in your snippet file content will be written as ]]> when you trigger the snippet.
tabTrigger

Defines the sequence of keys that must be pressed to insert this snippet. After typing this sequence, the snippet will kick in as soon as you hit the Tab key.

A tab trigger is an implicit key binding.

scope
Scope selector determining the context where the snippet will be active. See Scopes for more information.
description
Used when showing the snippet in the Snippets menu. If not present, Sublime Text defaults to the file name of the snippet.

With this information, you can start writing your own snippets as described in the next sections.

Note

In the interest of brevity, we’re only including the content element’s text in examples unless otherwise noted.

Snippet Features

Environment Variables

Snippets have access to contextual information in the form of environment variables. The values of the variables listed below are set automatically by Sublime Text.

You can also add your own variables to provide extra information. These custom variables are defined in .sublime-options files.

$PARAM1 .. $PARAMn Arguments passed to the insert_snippet command. (Not covered here.)
$SELECTION The text that was selected when the snippet was triggered.
$TM_CURRENT_LINE Content of the cursor’s line when the snippet was triggered.
$TM_CURRENT_WORD Word under the cursor when the snippet was triggered.
$TM_FILENAME Name of the file being edited, including extension.
$TM_FILEPATH Path to the file being edited.
$TM_FULLNAME User’s user name.
$TM_LINE_INDEX Column where the snippet is being inserted, 0 based.
$TM_LINE_NUMBER Row where the snippet is being inserted, 1 based.
$TM_SELECTED_TEXT An alias for $SELECTION.
$TM_SOFT_TABS YES if translate_tabs_to_spaces is true, otherwise NO.
$TM_TAB_SIZE Spaces per-tab (controlled by the tab_size option).

Let’s see a simple example of a snippet using variables:

====================================
USER NAME:          $TM_FULLNAME
FILE NAME:          $TM_FILENAME
 TAB SIZE:          $TM_TAB_SIZE
SOFT TABS:          $TM_SOFT_TABS
====================================

# Output:
====================================
USER NAME:          guillermo
FILE NAME:          test.txt
 TAB SIZE:          4
SOFT TABS:          YES
====================================

Fields

With the help of field markers, you can cycle through positions within the snippet by pressing the Tab key. Fields are used to walk you through the customization of a snippet after it’s been inserted.

First Name: $1
Second Name: $2
Address: $3

In the example above, the cursor will jump to $1 if you press Tab once. If you press Tab a second time, it will advance to $2, etc. You can also move backwards in the series with Shift+Tab. If you press Tab after the highest tab stop, Sublime Text will place the cursor at the end of the snippet’s content so that you can resume normal editing.

If you want to control where the exit point should be, use the $0 mark. By default, this is the end of the snippet.

You can break out of the field cycle any time by pressing Esc.

Mirrored Fields

Identical field markers mirror each other: when you edit the first one, the rest will be populated in real time with the same value.

First Name: $1
Second Name: $2
Address: $3
User name: $1

In this example, “User name” will be filled out with the same value as “First Name”.

Placeholders

By expanding the field syntax a little bit, you can define default values for a field. Placeholders are useful whenever there’s a general case for your snippet, but you still want to keep it customizable.

First Name: ${1:Guillermo}
Second Name: ${2:López}
Address: ${3:Main Street 1234}
User name: $1

Variables can be used as placeholders:

First Name: ${1:Guillermo}
Second Name: ${2:López}
Address: ${3:Main Street 1234}
User name: ${4:$TM_FULLNAME}

And you can nest placeholders within other placeholders too:

Test: ${1:Nested ${2:Placeholder}}

Substitutions

In addition to the place holder syntax, tab stops can specify more complex operations with substitutions. Use substitutions to dynamically generate text based on a mirrored tab stop. Of course, the tab stop you want to use as variable has to be mirrored somewhere else in the snipept.

The substitution syntax has the following syntaxes:

  • ${var_name/regex/format_string/}
  • ${var_name/regex/format_string/options}
var_name
The variable name: 1, 2, 3...
regex
Perl-style regular expression: See the Boost library documentation.
format_string
See the Boost library documentation.
options
Optional. May be any of the following:
i
Case-insensitive regex.
g
Replace all occurrences of regex.
m
Don’t ignore newlines in the string.

With substitutions you can, for instance, underline text effortlessly:

      Original: ${1:Hey, Joe!}
Transformation: ${1/./=/g}

# Output:

      Original: Hey, Joe!
Transformation: =========