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Templates

Jujutsu supports a functional language to customize output of commands. The language consists of literals, keywords, operators, functions, and methods.

A couple of jj commands accept a template via -T/--template option.

Keywords

Keywords represent objects of different types; the types are described in a follow-up section.

Commit keywords

The following keywords can be used in jj log/jj obslog templates.

  • description: String
  • change_id: ChangeId
  • commit_id: CommitId
  • parents: List<Commit>
  • author: Signature
  • committer: Signature
  • working_copies: String: For multi-workspace repository, indicate working-copy commit as <workspace name>@.
  • current_working_copy: Boolean: True for the working-copy commit of the current workspace.
  • branches: String
  • tags: String
  • git_refs: String
  • git_head: String
  • divergent: Boolean: True if the commit's change id corresponds to multiple visible commits.
  • hidden: Boolean: True if the commit is not visible (a.k.a. abandoned).
  • conflict: Boolean: True if the commit contains merge conflicts.
  • empty: Boolean: True if the commit modifies no files.
  • root: Boolean: True if the commit is the root commit.

Operation keywords

The following keywords can be used in jj op log templates.

  • current_operation: Boolean
  • description: String
  • id: OperationId
  • tags: String
  • time: TimestampRange
  • user: String

Operators

The following operators are supported.

  • x.f(): Method call.
  • x ++ y: Concatenate x and y templates.

Global functions

The following functions are defined.

  • fill(width: Integer, content: Template) -> Template: Fill lines at the given width.
  • indent(prefix: Template, content: Template) -> Template: Indent non-empty lines by the given prefix.
  • label(label: Template, content: Template) -> Template: Apply label to the content. The label is evaluated as a space-separated string.
  • if(condition: Boolean, then: Template[, else: Template]) -> Template: Conditionally evaluate then/else template content.
  • concat(content: Template...) -> Template: Same as content_1 ++ ... ++ content_n.
  • separate(separator: Template, content: Template...) -> Template: Insert separator between non-empty contents.

Types

Boolean type

No methods are defined. Can be constructed with false or true literal.

Commit type

This type cannot be printed. All commit keywords are accessible as 0-argument methods.

CommitId / ChangeId type

The following methods are defined.

  • .short([len: Integer]) -> String
  • .shortest([min_len: Integer]) -> ShortestIdPrefix: Shortest unique prefix.

Integer type

No methods are defined.

List type

The following methods are defined.

  • .join(separator: Template) -> Template: Concatenate elements with the given separator.
  • .map(|item| expression) -> ListTemplate: Apply template expression to each element. Example: parents.map(|c| c.commit_id().short())

ListTemplate type

The following methods are defined. See also the List type.

  • .join(separator: Template) -> Template

OperationId type

The following methods are defined.

  • .short([len: Integer]) -> String

ShortestIdPrefix type

The following methods are defined.

  • .prefix() -> String
  • .rest() -> String
  • .upper() -> ShortestIdPrefix
  • .lower() -> ShortestIdPrefix

Signature type

The following methods are defined.

  • .name() -> String
  • .email() -> String
  • .username() -> String
  • .timestamp() -> Timestamp

String type

A string can be implicitly converted to Boolean. The following methods are defined.

  • .contains(needle: Template) -> Boolean
  • .first_line() -> String
  • .lines() -> List<String>: Split into lines excluding newline characters.
  • .upper() -> String
  • .lower() -> String
  • .starts_with(needle: Template) -> Boolean
  • .ends_with(needle: Template) -> Boolean
  • .remove_prefix(needle: Template) -> String: Removes the passed prefix, if present
  • .remove_suffix(needle: Template) -> String: Removes the passed suffix, if present
  • .substr(start: Integer, end: Integer) -> String: Extract substring. Negative values count from the end.

String literals

String literals must be surrounded by double quotes ("). The following escape sequences starting with a backslash have their usual meaning: \", \\, \n, \r, \t, \0. Other escape sequences are not supported. Any UTF-8 characters are allowed inside a string literal, with two exceptions: unescaped "-s and uses of \ that don't form a valid escape sequence.

Template type

Most types can be implicitly converted to Template. No methods are defined.

Timestamp type

The following methods are defined.

TimestampRange type

The following methods are defined.

  • .start() -> Timestamp
  • .end() -> Timestamp
  • .duration() -> String

Configuration

The default templates and aliases() are defined in the [templates] and [template-aliases] sections of the config respectively. The exact definitions can be seen in the cli/src/config/templates.toml file in jj's source tree.

New keywords and functions can be defined as aliases, by using any combination of the predefined keywords/functions and other aliases.

For example:

[template-aliases]
'commit_change_ids' = '''
concat(
  format_field("Commit ID", commit_id),
  format_field("Change ID", commit_id),
)
'''
'format_field(key, value)' = 'key ++ ": " ++ value ++ "\n"'