Jinja Rendering

nautobot_design_builder.jinja2

Jinja2 related filters and environment methods.

new_template_environment(root_context, base_dir=None, native_environment=False)

Create a new template environment that will resolve identifiers using the supplied root_context.

If base_dir is supplied, templates will be matched from the base directory provided.

Parameters:

Name	Type	Description	Default
root_context	Context	Context object to use when resolving missing identifiers in the rendering process	required
base_dir	str	Path, or list of paths, to use as search paths for finding templates.	None
native_environment	bool	To use native JinjaEnvironment	False

Returns:

Name	Type	Description
NativeEnvironment	NativeEnvironment	Jinja native environment

Source code in nautobot_design_builder/jinja2.py

def new_template_environment(root_context, base_dir=None, native_environment=False) -> NativeEnvironment:
    """Create a new template environment that will resolve identifiers using the supplied root_context.

    If base_dir is supplied, templates will be matched from the base directory provided.

    Args:
        root_context (design_builder.context.Context): Context object to use when resolving missing identifiers in the rendering process
        base_dir (str): Path, or list of paths, to use as search paths for finding templates.
        native_environment (bool): To use native JinjaEnvironment

    Returns:
        NativeEnvironment: Jinja native environment
    """

    class RenderContext(JinjaContext):
        """Custom jinja render context that will resolve values from the provided design builder context."""

        def resolve_or_missing(self, key):
            """Resolve the missing value from the current design builder context.

            Args:
                key (str): Variable name to attempt to resolve.

            Returns:
                The resolved value or jinja2.utils.missing
            """
            value = super().resolve_or_missing(key)
            if value is missing:
                if hasattr(root_context, key) or key in root_context:
                    value = root_context[key]
                elif key == "context":
                    value = root_context
            return value

    def context_class(*args, **kwargs):
        context = RenderContext(*args, **kwargs)
        return context

    loader = None
    if base_dir:
        loader = FileSystemLoader(base_dir)

    env_class = Environment
    if native_environment:
        env_class = NativeEnvironment

    env = env_class(
        loader=loader,
        trim_blocks=True,
        lstrip_blocks=True,
        undefined=StrictUndefined,
    )
    for name, func in engines["jinja"].env.filters.items():
        # Register standard Nautobot filters in the environment
        env.filters[name] = func

    env.context_class = context_class
    return env