Provide translation domain, context and target language when doing im…

…plicit conversion

Note that 'target_language' is no longer defined as a variable,
but as internal state (and disallowed as a variable name).

CHANGES.rst

@@ -3,6 +3,11 @@ Changes
 
 In next release ...
 
+- Implicit translation now provides the translation context, domain,
+  and target language to the translation function (if applicable). Previously,
+  the target language was provided, but this did not respect a change via
+  `i18n:target`.
+  (`#369 <https://github.com/malthe/chameleon/issues/369>`_)
 
 - Replace ``pkg_resources`` with newer and faster ``importlib.resources`` and
   ``importlib.metadata``. Just importing ``pkg_resources`` becomes slower and

src/chameleon/compiler.py

@@ -62,6 +62,7 @@
 COMPILER_INTERNALS_OR_DISALLOWED = {
     "econtext",
     "rcontext",
+    "target_language",
     "str",
     "int",
     "float",
@@ -173,7 +174,12 @@ def indent(s):
             try:
                 target = target.__html__
             except AttributeError:
-                __converted = convert(target)
+                __converted = translate(
+                    target,
+                    domain=__i18n_domain,
+                    context=__i18n_context,
+                    target_language=target_language
+                )
                 target = str(target) if target is __converted else __converted
             else:
                 target = target()""")
@@ -199,22 +205,32 @@ def func(target):
             try:
                 target = target.__html__
             except AttributeError:
-                __converted = convert(target)
+                __converted = translate(
+                    target,
+                    domain=__i18n_domain,
+                    context=__i18n_context,
+                    target_language=target_language
+                )
                 target = str(target) if target is __converted else __converted
             else:
                 target = target()
 
-        return target""")
+        return target"""
+)
 
 
 emit_translate = template(is_func=True,
-                          func_args=('target', 'msgid', 'target_language',
+                          func_args=('target', 'msgid',
                                      'default'),
                           func_defaults=(None,),
                           source=r"""
-    target = translate(msgid, default=default, domain=__i18n_domain,
-                       context=__i18n_context,
-                       target_language=target_language)""")
+    target = translate(
+        msgid,
+        default=default,
+        domain=__i18n_domain,
+        context=__i18n_context,
+        target_language=target_language
+    )""")
 
 
 emit_func_convert_and_escape = template(
@@ -240,7 +256,12 @@ def func(target, quote, quote_entity, default, default_marker):
                 try:
                     target = target.__html__
                 except:
-                    __converted = convert(target)
+                    __converted = translate(
+                        target,
+                        domain=__i18n_domain,
+                        context=__i18n_context,
+                        target_language=target_language
+                    )
                     target = str(target) if target is __converted \
                              else __converted
                 else:
@@ -408,7 +429,6 @@ def __call__(self, name, engine):
                     "translate(msgid, domain=__i18n_domain, context=__i18n_context, target_language=target_language)",  # noqa:  E501 line too long
                     msgid=target,
                     mode="eval",
-                    target_language=load("target_language"),
                 )
         else:
             if translate:
@@ -429,7 +449,6 @@ def __call__(self, name, engine):
                     "translate(msgid, mapping=mapping, domain=__i18n_domain, context=__i18n_context, target_language=target_language)",   # noqa:  E501 line too long
                     msgid=ast.Str(
                         s=formatting_string),
-                    target_language=load("target_language"),
                     mapping=ast.Dict(
                         keys=keys,
                         values=values),
@@ -926,10 +945,7 @@ def visit_Translate(self, node, target):
         else:
             msgid = target
         return self.translate(node.node, target) + \
-            emit_translate(
-            target, msgid, "target_language",
-            default=target
-        )
+            emit_translate(target, msgid, default=target)
 
     def visit_Static(self, node, target):
         value = annotated(node)
@@ -954,7 +970,6 @@ class Compiler:
     defaults = {
         'translate': Symbol(simple_translate),
         'decode': Builtin("str"),
-        'convert': Builtin("str"),
         'on_error_handler': Builtin("str")
     }
 
@@ -1191,8 +1206,9 @@ def visit_Macro(self, node):
                     param("rcontext"),
                     param("__i18n_domain"),
                     param("__i18n_context"),
+                    param("target_language"),
                 ],
-                defaults=[load("None"), load("None")],
+                defaults=[load("None"), load("None"), load("None")],
             ),
             body=body
         )
@@ -1202,13 +1218,22 @@ def visit_Macro(self, node):
     def visit_Text(self, node):
         yield EmitText(node.value)
 
+    # TODO Refactor!
+
     def visit_Domain(self, node):
         backup = "__previous_i18n_domain_%s" % mangle(id(node))
         return template("BACKUP = __i18n_domain", BACKUP=backup) + \
             template("__i18n_domain = NAME", NAME=ast.Str(s=node.name)) + \
             self.visit(node.node) + \
             template("__i18n_domain = BACKUP", BACKUP=backup)
 
+    def visit_Target(self, node):
+        backup = "__previous_i18n_target_%s" % mangle(id(node))
+        return template("BACKUP = target_language", BACKUP=backup) + \
+            self._engine(node.expression, store("target_language")) + \
+            self.visit(node.node) + \
+            template("target_language = BACKUP", BACKUP=backup)
+
     def visit_TxContext(self, node):
         backup = "__previous_i18n_context_%s" % mangle(id(node))
         return template("BACKUP = __i18n_context", BACKUP=backup) + \
@@ -1253,9 +1278,7 @@ def visit_Content(self, node):
         body = self._engine(node.expression, store(name))
 
         if node.translate:
-            body += emit_translate(
-                name, name, load_econtext("target_language")
-            )
+            body += emit_translate(name, name)
 
         if node.char_escape:
             body += template(
@@ -1441,8 +1464,7 @@ def visit_Translate(self, node):
             "msgid, mapping=mapping, default=default, domain=__i18n_domain, context=__i18n_context, target_language=target_language))",  # noqa:  E501 line too long
             msgid=msgid,
             default=default,
-            mapping=mapping,
-            target_language=load_econtext("target_language"))
+            mapping=mapping)
 
         # pop away translation block reference
         self._translations.pop()
@@ -1603,7 +1625,8 @@ def visit_UseInternalMacro(self, node):
             render = "render_%s" % mangle(node.name)
         token_reset = template("__token = None")
         return token_reset + template(
-            "f(__stream, econtext.copy(), rcontext, __i18n_domain)",
+            "f(__stream, econtext.copy(), rcontext, "
+            "__i18n_domain, __i18n_context, target_language)",
             f=render) + \
             template("econtext.update(rcontext)")
 
@@ -1690,10 +1713,12 @@ def visit_UseExternalMacro(self, node):
                             param("rcontext"),
                             param("__i18n_domain"),
                             param("__i18n_context"),
+                            param("target_language"),
                         ],
                         defaults=[
                             load("__i18n_domain"),
-                            load("__i18n_context")],
+                            load("__i18n_context"),
+                            load("target_language"),],
                     ),
                     body=body or [
                         ast.Pass()],
@@ -1730,7 +1755,7 @@ def visit_UseExternalMacro(self, node):
             ) +
             template(
                 "__m(__stream, econtext.copy(), "
-                "rcontext, __i18n_domain)"
+                "rcontext, __i18n_domain, __i18n_context, target_language)"
             ) +
             template("econtext.update(rcontext)")
         )

src/chameleon/nodes.py

@@ -238,6 +238,12 @@ class Domain(Node):
     _fields = "name", "node"
 
 
+class Target(Node):
+    """Update translation target."""
+
+    _fields = "expression", "node"
+
+
 class TxContext(Node):
     """Update translation context."""
 

src/chameleon/template.py

@@ -199,8 +199,14 @@ def render(self, **__kw):
         rcontext = {}
         self.cook_check()
         stream = self.output_stream_factory()
+        target_language = __kw.get("target_language")
         try:
-            self._render(stream, econtext, rcontext)
+            self._render(
+                stream,
+                econtext,
+                rcontext,
+                target_language=target_language
+            )
         except RecursionError:
             raise
         except BaseException:

src/chameleon/tests/inputs/079-implicit-i18n.pt

@@ -12,5 +12,8 @@
       <br />
       bar.
     </div>
+    <div tal:define="Message import:chameleon.tests.test_templates.Message" i18n:target="string:fr">
+      ${Message()}
+    </div>
   </body>
 </html>

src/chameleon/tests/inputs/124-translation-target.pt

@@ -2,5 +2,6 @@
   <body>
     <h1 i18n:translate="" i18n:target="string:fr">Hello world!</h1>
     <p i18n:translate="" i18n:target="default">It's a big world.</p>
+    <p>${target_language}</p>
   </body>
 </html>

src/chameleon/tests/outputs/079-en.pt

@@ -12,5 +12,8 @@
       <br />
       bar. ('bar.' translation into 'en')
     </div>
+    <div>
+      Message ('message' translation into 'fr')
+    </div>
   </body>
 </html>

src/chameleon/tests/outputs/079.pt

@@ -12,5 +12,8 @@
       <br />
       bar.
     </div>
+    <div>
+      Message ('message' translation into 'fr')
+    </div>
   </body>
 </html>

src/chameleon/tests/outputs/124-en.pt

@@ -2,5 +2,6 @@
   <body>
     <h1>Hello world! ('Hello world!' translation into 'fr')</h1>
     <p>It's a big world. ('It's a big world.' translation into 'en')</p>
+    <p>en</p>
   </body>
-</html>
+</html>

src/chameleon/tests/outputs/124.pt

@@ -2,5 +2,6 @@
   <body>
     <h1>Hello world! ('Hello world!' translation into 'fr')</h1>
     <p>It's a big world.</p>
+    <p></p>
   </body>
-</html>
+</html>

src/chameleon/tests/test_templates.py

@@ -496,7 +496,7 @@ class TestException(Exception):
             def __init__(self, *args, **kwargs):
                 calls.append((args, kwargs))
 
-        def _render(stream, econtext, rcontext):
+        def _render(stream, econtext, rcontext, **kw):
             exc = TestException('foo', bar='baz')
             rcontext['__error__'] = ('expression', 1, 42, 'test.pt', exc),
             raise exc

src/chameleon/zpt/program.py

@@ -395,22 +395,6 @@ def visit_element(self, start, end, children):
             if defines is None:
                 raise ParseError("Invalid define syntax.", clause)
 
-        # i18n:target
-        try:
-            target_language = ns[I18N, 'target']
-        except KeyError:
-            pass
-        else:
-            # The name "default" is an alias for the target language
-            # variable. We simply replace it.
-            target_language = target_language.replace(
-                'default', 'target_language'
-            )
-
-            defines.append(
-                ('local', ("target_language", ), target_language)
-            )
-
         assignments = [
             nodes.Assignment(
                 names, nodes.Value(expr), context == "local")
@@ -509,6 +493,17 @@ def CASE(node):
         else:
             CONTEXT = partial(nodes.TxContext, clause)
 
+        # i18n:target
+        try:
+            clause = ns[I18N, 'target']
+        except KeyError:
+            TARGET = skip
+        else:
+            TARGET = lambda node: nodes.Define(  # noqa:  E731 do not assign a lambda expression, use a def
+                [nodes.Alias(["default"], "target_language")],
+                nodes.Target(clause, node)
+            )
+
         # i18n:name
         try:
             clause = ns[I18N, 'name']
@@ -532,6 +527,7 @@ def CASE(node):
             SWITCH,
             DOMAIN,
             CONTEXT,
+            TARGET,
         )
 
         # metal:fill-slot

src/chameleon/zpt/template.py

@@ -314,15 +314,11 @@ def decode(inst, encoding=encoding):
         else:
             decode = bytes.decode
 
-        target_language = _kw.get('target_language')
-
         setdefault = _kw.setdefault
         setdefault("__translate", translate)
-        setdefault("__convert",
-                   partial(translate, target_language=target_language))
         setdefault("__decode", decode)
-        setdefault("target_language", None)
         setdefault("__on_error_handler", self.on_error_handler)
+        setdefault("target_language", None)
 
         # Make sure we have a repeat dictionary
         if 'repeat' not in _kw: