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User Guide


ApplySyntax is based on the idea of creating rules for applying certain syntaxes to specific files. You define the rules, the plugin checks them. The first one to pass wins.

ApplySyntax allows you to create your own custom rules. The easiest way to get started is to press CtrlShiftP (Win, Linux) or CmdShiftP (macOS) to bring up the quick panel and start typing ApplySyntax: Settings. Alternatively, you can create a settings file called ApplySyntax.sublime-settings in your Packages/User folder. You can override the default settings in Packages/ApplySyntax/ApplySyntax.sublime-settings by setting them in your Packages/User/ApplySyntax.sublime-settings file. You can override any setting to meet your needs. To prepend rules to the default rule set, you can create a key called syntaxes (modifying default_syntaxes will wipe out all the default rules and is not recommended as you won't get the latest updates).


When create syntax rules, you will need to use the syntax file name, not the name that shows in the status bar. A few commands have been added to make it easy to determine what to put into a syntax rule.

ApplySyntax: Browse Syntaxes

This command will show a quick panel of all the syntaxes in your Sublime Text install. You can fuzzy search them, and when you select one, it will be copied to the clipboard in a form compatible to be used in a syntax rule. Simply paste it in the rule.

New 4.0

ApplySyntax: Browse Syntaxes is new in 4.0.

ApplySyntax: Copy Current Syntax to Clipboard

This command will copy the current syntax in the active view to your clipboard in a form that is compatible to be used in a syntax rule. Simply paste it in the rule.

New 4.0

ApplySyntax: Copy Current Syntax to Clipboard is new in 4.0.

Creating Rules

Each rule is a dictionary within the syntax array. Let's take a look at the top level parameters.


The syntax attribute is the syntax file that will be applied to a view which meets the criteria defined in the rule.

For syntax files you must specify the path to the syntax file. The plugin is capable of supporting multiple levels of folder nesting if you need it to. For example, if you had all of your tmLanguage files for Rails organized in a folder like this: Packages/Rails/Language/*.tmLanguage, and you were looking to use the Ruby Haml.tmLanguage file, the path to name translation would simply be: Packages/Rails/Language/Ruby Haml.tmLanguageRails/Language/Ruby Haml.

"syntax": "Rails/Language/Ruby Haml"

Notice that the paths are relative to the Packages folder. Also, notice that we don't specify the extension. Sublime Text in build 3084 added a new language syntax with the extension sublime-syntax. In Sublime builds >= 3084, ApplySyntax will first default to sublime-syntax and fall back to tmLanguage if it cannot find the the other format. If you want to force the syntax, just specify the extension; the extension must be either sublime-syntax or tmLanguage.

"syntax": "Rails/Language/Ruby Haml.tmLanguage"

If it is desirable for the syntax rule to reference multiple tmLanguage files because it is not known which package will be on a machine, you can set the syntax as an array of syntaxes as shown in the following example. The first one found will be used.

"syntax": ["RSpec/RSpec", "RSpec (snippets and syntax)/Syntaxes/RSpec"]

Notice that each syntax file has a different path since they come from completely different plugins.

Lastly, if using Package Control, it is likely that most, if not all, of your packages will be zipped with the extension .sublime-package in the Installed Packages folder instead of Packages. These will be handled exactly like plugins installed under Packages. The one difference is that you treat the zip bundle as a folder without the .sublime-package extension. So if we had a syntax file located in a zipped bundle: Installed Packages/Rails.sublime-package/Language/Ruby Haml.tmLanguageRails/Language/Ruby Haml.

"syntax": "Rails/Language/Ruby Haml"


The extensions attribute is used to define extensions to apply a syntax to. extensions is an array of strings where each string is an extension. No . is needed when defining extensions, unless it is desired to target a dot file like .gitignore, then you would include the ..

        "syntax": "YAML/YAML",
        "extensions": [".gemrc", "yml", "yml.dist"]

extensions is evaluated before all other rules, and it never takes part in "match all" rule sets as it is run separate from the normal rule sets; if an extension is matched here, all other rules will be skipped.

An added benefit of extensions, if you are using ST3 and set add_exts_to_lang_settings to true, is that ApplySyntax will add the extensions to the specified syntax language's settings file in your User folder. By doing this, Sublime Text will be able to show the associated icon for the file type in the sidebar. Apply syntax will also create a file ApplySyntax.ext-list in your User folder and track which extension it added so that if you remove a rule, ApplySyntax will only remove the extensions it added to the language file in question. If you do not like this functionality, you can simply disable add_exts_to_lang_settings by setting it to false.


add_exts_to_lang_settings will not be applied to extensions found in a project specific rule, as project specific rules are not global, but the effects of add_exts_to_lang_settings are global.


match is a setting that you either include or omit. When included, you set it to all. When set, all rules defined must be met for a match to be considered successful. match ignores the extensions key as extensions never take part in "match all" rule sets. If you want to include an extension rule in a "match all" rule set, then a file_path rule should be used.

    "match": "all"

So in this case, all the rules must match for the syntax to be applied:

     "syntax": "Handlebars/Handlebars",
     "match": "all",
     "rules": [
         {"file_path": ".*\\.html$"},
         {"contains": "<script [^>]*type=\"text\\/x-handlebars\"[^>]*>"}

In this case, there is no match key, so only one rule needs to match:

        "syntax": "Ruby/Ruby",
        "rules": [
            {"file_path": ".*/Gemfile$"},
            {"file_path": ".*/Capfile$"},
            {"file_path": ".*/Guardfile$"},
            {"file_path": ".*/[Rr]akefile$"},
            {"file_path": ".*/Berksfile$"},
            {"file_path": ".*/[Cc]heffile$"},
            {"file_path": ".*/Thorfile$"},
            {"file_path": ".*/Podfile$"},
            {"file_path": ".*/$"},
            {"file_path": ".*/Vagrantfile(/..*)?$"},
            {"file_path": ".*\\.thor$"},
            {"file_path": ".*\\.rake$"},
            {"file_path": ".*\\.simplecov$"},
            {"file_path": ".*\\.jbuilder$"},
            {"file_path": ".*\\.rb$"},
            {"file_path": ".*\\.podspec$"},
            {"file_path": ".*\\.rabl$"},
            {"interpreter": "ruby"}


rules is an array of rules that can be used to target specific files with your defined syntax file. The rules are processed until the first rule matches, so order your rules in a way that makes sense to you.

Globmatch Rule

A globmatch rule defines a glob pattern to match a file path against. Regex is more powerful, but often, a glob pattern can be far less cumbersome and easier to specify patterns that work cross platform.

ApplySyntax uses the wcmatch library with the following flags enabled:

  • GLOBSTAR: Allows you to match 0 or more directories with **.
  • BRACE: Allows you to use Bash style brace expansions for patterns (a{b,c}ab ac).
  • EXTGLOB: Allows you to use extended glob patterns such as @(file1|file2), etc.
  • NEGATE: Allows you to use exclusion patterns that filter inclusion patterns (['**/*.py', '!**/']).
  • DOTGLOB: Allows * and other such patterns to match file names that start with ..

globmatch rule takes either a string pattern or list of strings patterns. You do not have to specify Windows paths with \\, just use /.

{"globmatch": "**/*.py"}

When providing a list, all patterns are evaluated together. This allows you to apply excludes:

{"globmatch": ["**/*.py", "!**/"]}

If necessary, you can specify case sensitivity:

{"globmatch": "**/*.py", "case": true}

New 4.0

globmatch rules are new in 4.0.

File Path Rule

A file_path rule defines a regex to match against the complete file path. The pattern is always anchored to the beginning of the path, as if there were an implicit ^ — so the pattern /a/b/c will match the file /a/b/c/, but not the file /x/y/z/a/b/c/ (You may include an explicit ^ at the beginning of the pattern, as some of the default rules do — but the result is the same either way.)

For backwards compatibility with older versions of ApplySyntax, the rule name file_name is also accepted, and functions exactly like file_path.

{"file_path": ".*\\.xml(\\.dist)?$"},

Changed 4.0

On Windows systems, paths are now normalized to from using \ to /. This makes creating patterns for cross platform use much easier, but it may break some existing rules in the short term.

First Line Rule

A first_line rule allows you to check whether the first line of the file's content matches a given regex. As with file_path rules, the pattern is always anchored to the beginning of the line.

{"first_line": "^<\\?xml"},

Interpreter (Shebang)

An interpreter rule does the same thing as a first_line rule that uses a regex to match an interpreter directive (shebang). The difference being that ApplySyntax will construct the regex for you.

So a first_line rule:

{"first_line": "^#\\!(?:.+)ruby"}

Can be simplified as:

{"interpreter": "ruby"}

For backwards compatibility with older versions of ApplySyntax, the rule name binary is also accepted, and functions exactly like interpreter.

Function Rule

This is an example of using a custom function to decide whether or not to apply a syntax. This is done via ApplySyntax plugins. The plugin file should be under a plugin folder.

The function rule takes two parameters. The first is source and is the plugin source file. It is defined as if you were importing a python plugin. If you had a plugin in Packages/ApplySyntax/as_plugins/, it would be defined under source as ApplySyntax.as_plugins.is_rails_file. Function rules still support the legacy way: ApplySyntax/as_plugins/is_rails_file, but it is recommended to use the dot notation as it makes more sense from a Python import perspective.

The second parameter is args and is optional. args is a dictionary of the keyword arguments the function rule plugin accepts.

The plugin must have a function defined as syntax_test. syntax_test will be the function called within the plugin file and accepts an argument file_path (which is the full path to the file being evaluated), and any custom keyword arguments desired by the user. The plugin must return either True or False.

{"function": {"source": "User.plugins.myplugin", "args": {'foo': "bar"}}}


def syntax_test(file_path, foo):
    # Some test logic
    return False # True or False


When placing a function rule module in a package, it is advised to put it in a sub-folder. The sub-folder does not need an, it just needs your module(s).

Content Rule

Sometimes a file name or first line search is just not enough and maybe a function rule is overkill. In this case, maybe searching the content of a file can be enough. You can search a file's content with regex for a specific token via the contains rule.

{"contains": "<script [^>]*type=\"text\\/x-handlebars\"[^>]*>"}


It is recommended to pair contains rules with other rules via the "match": "all" option to ensure you don't search every file (which can significantly slow down the editor); this will also help ensure get more reliable matches. If pairing with other rules as dependencies, it is advised to pair the contains rule after the other required rule(s) to ensure you search the content of as few files as possible.

Also, try to use very specific regex to ensure you don't get false positives.

Extension Trimming

Sometimes a file may have a trailing extension that prevents it from matching a rule, but if it was trimmed off, it would match. By creating an extension trimming rule, you target files that do not initial match and send them back through the pipe without it's last extension.

Currently, an extension trimming rule only contains a file_path pattern.

"ext_trim": [{"file_path": ".*\\.py3\\.temp"}]

You can also use globmatch patterns:

"ext_trim": [{"globmatch": "**/*.py3.temp"}]

So, if we had a file named test.py3.temp, it normally wouldn't match one of default rules. With the above rule, the file would be retried as test.py3 and would match the Python syntax rule.

New 4.0

globmatch support was added in 4.0.

Changed 4.0

On Windows systems, paths are now normalized to from using \ to /. This makes creating patterns for cross platform use much easier, but it may break some existing rules in the short term.

Project Specific Rules

To define project specific syntaxes, just create a settings key in your project file (if it doesn't already exist) and then and an additional key under settings called project_syntaxes or project_ext_trim.

project_syntaxes is an array; just add your syntax rules to project_syntaxes just like you would add them to syntaxes in your user settings file, and ApplySyntax will prepend the rules to the beginning of your defined rules. The order of rules is as follows: project → user → default.

project_ext_trim is also an array, and you can trim rules just as you would to ext_trim in your user settings file.

There is one difference between project specific rules and global rules. In project rules, the extensions key will not be applied to the associated syntax language settings file as project specific rules are not global, but language settings files are global.

    "settings": {
        "project_syntaxes": [
                "syntax": "XML/XML",
                "rules": [
                    {"file_path": ".*\\.xml(\\.dist)?$"},
                    {"first_line": "^<\\?xml"}
        "project_ext_trim": [
            {"file_path": ".*\\.file.temp"}

Settings Options

There are a couple of general settings found in ApplySyntax.sublime-settings.

Re-Raise Exceptions

If an exception occurs when processing a function, this will re-raised the captured exception in Sublime's console so the user get feedback. This is really only useful to those writing functions. The average user shouldn't need this. By default, the setting will be set to false.

    "reraise_exceptions": false,

New File Syntax

If you want to have a syntax applied when new files are created, set new_file_syntax to the name of the syntax to use. The format is exactly the same as the syntax parameter in the syntax rules mentioned earlier. For example, if you want to have a new file use JavaScript syntax, set new_file_syntax to JavaScript/JavaScript. The default is false.

    "new_file_syntax": "JavaScript/JavaScript",

Add Extensions to Language Settings

To enable adding defined extensions to language settings, just set add_exts_to_lang_settings to true. See Extensions for more info.

    "add_exts_to_lang_settings": true,

Troubleshooting and Debugging

By default, the debug setting is turned on so that users have some form of visual feedback in the console that ApplySyntax is working. This can be turned off by setting debug to false. If developing, you can set debug to verbose to get even more info in the console.

    // Control level of logging in the console.
    // (true|false|"verbose")
    "debug": true,

Last update: August 23, 2020
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