| # Copyright 2019 The Chromium Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| import mako.lookup |
| import mako.template |
| |
| |
| class MakoRenderer(object): |
| """Represents a renderer object implemented with Mako templates.""" |
| |
| def __init__(self, template_dirs=None): |
| template_dirs = template_dirs or [] |
| self._template_lookup = mako.lookup.TemplateLookup( |
| directories=template_dirs) |
| |
| self._caller_stack = [] |
| |
| def render(self, |
| caller, |
| template_path=None, |
| template_text=None, |
| template_vars=None): |
| """ |
| Renders the template with variable bindings. |
| |
| It's okay to invoke |render| method recursively and |caller| is pushed |
| onto the call stack, which is accessible via |callers| and |last_caller| |
| methods. |
| |
| Args: |
| template_path: A filepath to a template file. |
| template_text: A text content to be used as a template. Either of |
| |template_path| or |template_text| must be specified. |
| template_vars: Template variable bindings. |
| caller: An object to be pushed onto the call stack. |
| """ |
| |
| assert not (template_path is None and template_text is None) |
| assert not (template_path and template_text) |
| assert isinstance(template_vars, dict) |
| assert caller is not None |
| |
| self._caller_stack.append(caller) |
| |
| try: |
| if template_path: |
| template = self._template_lookup.get_template(template_path) |
| elif template_text: |
| template = mako.template.Template(text=template_text) |
| text = template.render(**template_vars) |
| finally: |
| self._caller_stack.pop() |
| |
| return text |
| |
| @property |
| def callers(self): |
| """ |
| Returns the callers of this renderer in the order from the last caller |
| to the first caller. |
| """ |
| return reversed(self._caller_stack) |
| |
| @property |
| def last_caller(self): |
| """Returns the last caller in the call stack of this renderer.""" |
| return self._caller_stack[-1] |
