Class Template

django/template/base.py:141–291

class Template:
    def __init__(self, template_string, origin=None, name=None, engine=None):
        # If Template is instantiated directly rather than from an Engine and
        # exactly one Django template engine is configured, use that engine.
        # This is required to preserve backwards-compatibility for direct use
        # e.g. Template('...').render(Context({...}))
        if engine is None:
            from .engine import Engine

            engine = Engine.get_default()
        if origin is None:
            origin = Origin(UNKNOWN_SOURCE)
        self.name = name
        self.origin = origin
        self.engine = engine
        self.source = str(template_string)  # May be lazy.
        self.nodelist = self.compile_nodelist()

    def __repr__(self):
        return '<%s template_string="%s...">' % (
            self.__class__.__qualname__,
            self.source[:20].replace("\n", ""),
        )

    def _render(self, context):
        return self.nodelist.render(context)

    def render(self, context):
        "Display stage -- can be called many times"
        with context.render_context.push_state(self):
            if context.template is None:
                with context.bind_template(self):
                    context.template_name = self.name
                    return self._render(context)
            else:
                return self._render(context)

    def compile_nodelist(self):
        """
        Parse and compile the template source into a nodelist. If debug
        is True and an exception occurs during parsing, the exception is
        annotated with contextual line information where it occurred in the
        template source.
        """
        if self.engine.debug:
            lexer = DebugLexer(self.source)
        else:
            lexer = Lexer(self.source)

        tokens = lexer.tokenize()
        parser = Parser(
            tokens,
            self.engine.template_libraries,
            self.engine.template_builtins,
            self.origin,
        )

        try: