Writing a template which displays only relevant parents

[Yuya Nishihara]

On Fri, 5 Feb 2016 14:21:02 +0100, Dr Rainer Woitok wrote:
> I have already found the  "revset" template function  in "man/man1/hg.1"
> but the description is rather terse and in particular it does not at all
> explain  the second argument  (if that  matters at  all for  the case at
> hand):
> 
>        revset(query[, formatargs...])
>               Execute a revision set query. See hg help revset.
> 
> Among several others I tried the following variants
> 
>    {ifeq(count(revset(p1rev:rev)),2),'*',{p1rev}:{p1node|short})}
>    {ifeq(revset(p1rev:rev),revset(last(p1rev:rev,2)),'*',{p1rev}:{p1node|short})}

You need to pass a string query. "hg help template" has some examples.

  {ifeq(count(revset('{p1rev}:{rev}')), 2, '*', '{p1rev}:{p1node|short}')}
or
  {ifeq(count(revset('%d:%d', p1rev, rev)), 2, '*', '{p1rev}:{p1node|short}')}

The latter isn't documented well.

> >                            But the smarts you want are already built into
> > "parents":
> 
> I assume,  with "smarts"  you refer to  splitting "parents" into a comma
> separated list  rather than to my real problem  of replacing the trivial
> parent with an asterisk.

You could do

  {if(parents, parents, '*')}

> Anyway, as you can see  from the output prod-
> uced by your template,  "{rev}" always refers  to the revision number of
> the changeset being logged  rather than to the revision numbers included
> in "parents".   That's exactly what originally caused me to spell it out
> in my template using "{p[12]rev}" and "{p[12]node}".  Is there something
> like "{parent.rev}"?

It seems "parents" isn't ported to new-style template yet. {parents % "{rev}"}
should work, but it doesn't now.

>    - Currently, my log template  sums up to almost  400 characters  in a
>      single line.  Attempts to split it  into several lines  by escaping
>      the lineend with a  backslash  in the usual manner  were not under-
>      stood by  the templater.   Is there a way  to split  templates into
>      several lines?

You can insert whitespaces in non-string part.

  x = blah blah{
      func(x,
      y)}

>    - Is there a way to "call" a user defined template from within anoth-
>      er user defined template?  As in:
> 
>      [templates]
>      log      = {headline}{... remaining "log" template ...}
>      tip      = {headline}{... remaining "tip" template ...}
>      heads    = {headline}{... remaining "heads" template ...}
>      headline = {... common sub-template for all other templates ...}

Not yet, but I'm thinking of it.

>    - In "man/man1/hg.1"  I simply did not understand the following pass-
>      age:
> 
>        · expr % "{template}"
> 
>        As seen in the above example, "{template}" is  interpreted  as  a  tem‐
>        plate.   To  prevent  it  from being interpreted, you can use an escape
>        character "{" or a raw string prefix, "r'...'".
> 
>      Is this just a typo and `"{"´ should be replaced with `"\{"´?

Yep. It looks like '\' is processed as an escape character of reStructuredText.