tests/test-template-engine.t

templater: keep default resources per template engine (API)

This allows us to register a repo object as a resource in hgweb template,
without loosing '{repo}' symbol:

  symbol('repo') -> mapping['repo'] (n/a) -> defaults['repo']
  resource('repo') -> mapping['repo'] (n/a) -> resources['repo']

I'm thinking of redesigning the templatekw API to take (context, mapping)
in place of **(context._resources + mapping), but that will be a big change
and not implemented yet.

props['templ'] is ported to the resources dict as an example.

.. api::

   mapping does not contain all template resources. use context.resource()
   in template functions.

  $ cat > engine.py << EOF
  > 
  > from mercurial import templater
  > 
  > class mytemplater(object):
  >     def __init__(self, loader, filters, defaults, resources, aliases):
  >         self.loader = loader
  >         self._resources = resources
  > 
  >     def process(self, t, map):
  >         tmpl = self.loader(t)
  >         for k, v in map.iteritems():
  >             if k in ('templ', 'ctx', 'repo', 'revcache', 'cache', 'troubles'):
  >                 continue
  >             if hasattr(v, '__call__'):
  >                 props = self._resources.copy()
  >                 props.update(map)
  >                 v = v(**props)
  >             v = templater.stringify(v)
  >             tmpl = tmpl.replace('{{%s}}' % k, v)
  >         yield tmpl
  > 
  > templater.engines['my'] = mytemplater
  > EOF
  $ hg init test
  $ echo '[extensions]' > test/.hg/hgrc
  $ echo "engine = `pwd`/engine.py" >> test/.hg/hgrc
  $ cd test
  $ cat > mymap << EOF
  > changeset = my:changeset.txt
  > EOF
  $ cat > changeset.txt << EOF
  > {{rev}} {{node}} {{author}}
  > EOF
  $ hg ci -Ama
  adding changeset.txt
  adding mymap
  $ hg log --style=./mymap
  0 97e5f848f0936960273bbf75be6388cd0350a32b test

  $ cat > changeset.txt << EOF
  > {{p1rev}} {{p1node}} {{p2rev}} {{p2node}}
  > EOF
  $ hg ci -Ama
  $ hg log --style=./mymap
  0 97e5f848f0936960273bbf75be6388cd0350a32b -1 0000000000000000000000000000000000000000
  -1 0000000000000000000000000000000000000000 -1 0000000000000000000000000000000000000000

invalid engine type:

  $ echo 'changeset = unknown:changeset.txt' > unknownenginemap
  $ hg log --style=./unknownenginemap
  abort: invalid template engine: unknown
  [255]

  $ cd ..