Overriding elements within templates.

[jacg]

jj op log shows me a bazillion changes with the timestamp 1 day ago. This really doesn't help me to find "that thing I did just after lunch yesterday".

How can I override a single component used in a template? In this example, that would be the timestamp.

jj config list --include-defaults | rg -A 10 builtin_op_log (is there a better approach?) shows me that

template-aliases.builtin_op_log_oneline = '''
label(if(current_operation, "current_operation"),
  coalesce(
    if(snapshot, format_snapshot_operation_oneline(self)),
    if(root, format_root_operation(self)),
    format_operation_oneline(self),
  )
)
'''

What would be an efficient way to drill down to discover the relevant component?

Once found, how could I override it?

Can it be overridden on the CLI, or would it require modifying the config file?

[bnjmnt4n]

The format_* "functions" are template aliases, which can be viewed via jj config list --include-defaults template-aliases. You'd likely want to look through the relevant functions to determine how the output is being rendered.

For example, the defaults for formatting operations based on looking at the above template are

template-aliases."format_operation_oneline(op)" = '''
separate(" ",
  format_short_operation_id(op.id()), op.user(), format_time_range(op.time()),
  op.description().first_line(),
  if(op.tags(), op.tags()),
) ++ "\n"
'''
template-aliases."format_snapshot_operation_oneline(op)" = 'format_operation_oneline(op)'

Based on that, the time range is rendered using format_time_range:

template-aliases."format_time_range(time_range)" = '''
  time_range.end().ago() ++ label("time", ", lasted ") ++ time_range.duration()'''

You can customize this to your liking by overriding the specific function. You can add a modified version of this alias to your config file, or even add the configuration on a per command basis, e.g. something like the following:

jj op log --config 'template-aliases."format_time_range(time_range)"=\'time_range.end() ++ label("time", ", lasted ") ++ time_range.duration()\''

(I usually do this to test out various changes before adding the final version to my config.)

You can also want to write your own templates without depending on any of these defaults if you think the defaults aren't suitable for you.

[tim-janik]

Can it be overridden on the CLI, or would it require modifying the config file?

There is detailed info on timestamps here:
https://jj-vcs.github.io/jj/latest/config/#relative-timestamps

E.g. this gives just absolute stamps:

 jj --config "template-aliases.'format_time_range(time_range)'='time_range.end()'" op log 

[martinvonz]

FWIW, I have this in my config:

[template-aliases]
'format_time_range(time_range)' = '''format_timestamp(time_range.start()) ++ label("time", ", lasted ") ++ time_range.duration()'''