override template aliases locally in templates

[mmlb]

I'd like to override a template-alias, lets say format_timestamp but only when running log with my custom template. I basically want to influence builtin_log_compact by tweaking the template-aliases it uses but leave other templates unaffected.

My reasoning is I'd like a terse log output by default but have a way to see fuller/default output if necessary, selfishly w minimal config on my end so I can benefit from updates to the builtins.

Ideally I could do something like:

[template]
log = '''
  format_short_signature(signature) = coalesce(signature.name().split(" ").first(), name_placeholder)
  format_timestamp(timestamp) = timestamp.ago()
  builtin_log_compact()
'''

[josephlou5]

I think this is already possible:

[template-aliases]
'format_short_signature(signature)' = '''
coalesce(signature.name().split(" ").first(), name_placeholder)
'''
'format_timestamp(timestamp)' = 'timestamp.ago()'

But you said "only when running log with my custom template", which I'm assuming means "I only want these overrides to apply when I run jj log, but not other commands"? If so, you can do this with conditional variables:

[[--scope]]
--when.commands = ["log"]
[--scope.template-aliases]
'format_short_signature(signature)' = '''
coalesce(signature.name().split(" ").first(), name_placeholder)
'''
'format_timestamp(timestamp)' = 'timestamp.ago()'

(Sorry, accidentally hit cmd+enter, so I commented without finishing what I was typing.)