# HG changeset patch
# User FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
# Date 1459271444 -32400
# Node ID cc103bd0dbf9617608d36b878f9efd78addeb714
# Parent  9a6fa1d93bc89e77c8120f258468e282c45e4d9b
registrar: add templatefunc to mark a function as template function (API)

This patch also adds loadfunction() to templater, because this
combination helps to figure out how they cooperate with each other.

Listing up loadfunction() in dispatch.extraloaders causes implicit
loading template function at loading (3rd party) extension.

This patch explicitly tests whether templatefunc decorator works as
expected, because there is no bundled extension, which defines
template function.

This change requires that "templatefunc" attribute of (3rd party)
extension is registrar.templatefunc or so.

diff -r 9a6fa1d93bc8 -r cc103bd0dbf9 mercurial/dispatch.py
--- a/mercurial/dispatch.py	Wed Mar 30 02:10:44 2016 +0900
+++ b/mercurial/dispatch.py	Wed Mar 30 02:10:44 2016 +0900
@@ -37,6 +37,7 @@
     revset,
     templatefilters,
     templatekw,
+    templater,
     ui as uimod,
     util,
 )
@@ -768,6 +769,7 @@
     ('filesetpredicate', fileset, 'loadpredicate'),
     ('revsetpredicate', revset, 'loadpredicate'),
     ('templatefilter', templatefilters, 'loadfilter'),
+    ('templatefunc', templater, 'loadfunction'),
     ('templatekeyword', templatekw, 'loadkeyword'),
 ]
 
diff -r 9a6fa1d93bc8 -r cc103bd0dbf9 mercurial/registrar.py
--- a/mercurial/registrar.py	Wed Mar 30 02:10:44 2016 +0900
+++ b/mercurial/registrar.py	Wed Mar 30 02:10:44 2016 +0900
@@ -216,3 +216,29 @@
 
     Otherwise, explicit 'templatefilters.loadkeyword()' is needed.
     """
+
+class templatefunc(_templateregistrarbase):
+    """Decorator to register template function
+
+    Usage::
+
+        templatefunc = registrar.templatefunc()
+
+        @templatefunc('myfunc(arg1, arg2[, arg3])')
+        def myfuncfunc(context, mapping, args):
+            '''Explanation of this template function ....
+            '''
+            pass
+
+    The first string argument is used also in online help.
+
+    'templatefunc' instance in example above can be used to
+    decorate multiple functions.
+
+    Decorated functions are registered automatically at loading
+    extension, if an instance named as 'templatefunc' is used for
+    decorating in extension.
+
+    Otherwise, explicit 'templater.loadfunction()' is needed.
+    """
+    _getname = _funcregistrarbase._parsefuncdecl
diff -r 9a6fa1d93bc8 -r cc103bd0dbf9 mercurial/templater.py
--- a/mercurial/templater.py	Wed Mar 30 02:10:44 2016 +0900
+++ b/mercurial/templater.py	Wed Mar 30 02:10:44 2016 +0900
@@ -1069,5 +1069,11 @@
 
     raise RuntimeError("No hgweb templates found in %r" % paths)
 
+def loadfunction(ui, extname, registrarobj):
+    """Load template function from specified registrarobj
+    """
+    for name, func in registrarobj._table.iteritems():
+        funcs[name] = func
+
 # tell hggettext to extract docstrings from these functions:
 i18nfunctions = funcs.values()
diff -r 9a6fa1d93bc8 -r cc103bd0dbf9 tests/test-command-template.t
--- a/tests/test-command-template.t	Wed Mar 30 02:10:44 2016 +0900
+++ b/tests/test-command-template.t	Wed Mar 30 02:10:44 2016 +0900
@@ -3693,3 +3693,26 @@
   [255]
 
   $ cd ..
+
+Test that template function in extension is registered as expected
+
+  $ cd a
+
+  $ cat <<EOF > $TESTTMP/customfunc.py
+  > from mercurial import registrar
+  > 
+  > templatefunc = registrar.templatefunc()
+  > 
+  > @templatefunc('custom()')
+  > def custom(context, mapping, args):
+  >     return 'custom'
+  > EOF
+  $ cat <<EOF > .hg/hgrc
+  > [extensions]
+  > customfunc = $TESTTMP/customfunc.py
+  > EOF
+
+  $ hg log -r . -T "{custom()}\n" --config customfunc.enabled=true
+  custom
+
+  $ cd ..