dify/api/libs/email_template_renderer.py
2025-12-26 12:34:46 +08:00

50 lines
1.7 KiB
Python

"""
Email template rendering helpers with configurable safety modes.
"""
import time
from collections.abc import Mapping
from typing import Any
from flask import render_template_string
from jinja2.runtime import Context
from jinja2.sandbox import ImmutableSandboxedEnvironment
from configs import dify_config
from configs.feature import TemplateMode
class SandboxedEnvironment(ImmutableSandboxedEnvironment):
"""Sandboxed environment with execution timeout."""
def __init__(self, timeout: int, *args: Any, **kwargs: Any):
self._deadline = time.time() + timeout if timeout else None
super().__init__(*args, **kwargs)
def call(self, context: Context, obj: Any, *args: Any, **kwargs: Any) -> Any:
if self._deadline is not None and time.time() > self._deadline:
raise TimeoutError("Template rendering timeout")
return super().call(context, obj, *args, **kwargs)
def render_email_template(template: str, substitutions: Mapping[str, str]) -> str:
"""
Render email template content according to the configured template mode.
In unsafe mode, Jinja expressions are evaluated directly.
In sandbox mode, a sandboxed environment with timeout is used.
In disabled mode, the template is returned without rendering.
"""
mode = dify_config.MAIL_TEMPLATING_MODE
timeout = dify_config.MAIL_TEMPLATING_TIMEOUT
if mode == TemplateMode.UNSAFE:
return render_template_string(template, **substitutions)
if mode == TemplateMode.SANDBOX:
env = SandboxedEnvironment(timeout=timeout)
tmpl = env.from_string(template)
return tmpl.render(substitutions)
if mode == TemplateMode.DISABLED:
return template
raise ValueError(f"Unsupported mail templating mode: {mode}")