1from __future__ import annotations
 2
 3from collections.abc import Callable
 4from typing import Any
 5
 6from plain.http import ResponseBase
 7from plain.utils.cache import patch_vary_headers
 8from plain.views import TemplateView
 9
10from .templates import render_template_fragment
11
12
13class HTMXView(TemplateView):
14    """View with HTMX-specific functionality."""
15
16    def render_template(self) -> str:
17        template = self.get_template()
18        context = self.get_template_context()
19
20        if self.is_htmx_request() and self.get_htmx_fragment_name():
21            return render_template_fragment(
22                template=template._jinja_template,
23                fragment_name=self.get_htmx_fragment_name(),
24                context=context,
25            )
26
27        return template.render(context)
28
29    def get_response(self) -> ResponseBase:
30        response = super().get_response()
31        # Tell browser caching to also consider the fragment header,
32        # not just the url/cookie.
33        patch_vary_headers(
34            response, ["HX-Request", "Plain-HX-Fragment", "Plain-HX-Action"]
35        )
36        return response
37
38    def get_request_handler(self) -> Callable[[], Any] | None:
39        if self.is_htmx_request() and self.request.method:
40            # You can use an htmx_{method} method on views
41            # (or htmx_{method}_{action} for specific actions)
42            method = f"htmx_{self.request.method.lower()}"
43
44            if action := self.get_htmx_action_name():
45                # If an action is specified, we throw an error if
46                # the associated method isn't found
47                return getattr(self, f"{method}_{action}")
48
49            if handler := getattr(self, method, None):
50                # If it's just an htmx post, for example,
51                # we can use a custom method or we can let it fall back
52                # to a regular post method if it's not found
53                return handler
54
55        return super().get_request_handler()
56
57    def is_htmx_request(self) -> bool:
58        return self.request.headers.get("HX-Request") == "true"
59
60    def get_htmx_fragment_name(self) -> str:
61        # A custom header that we pass with the {% htmxfragment %} tag
62        return self.request.headers.get("Plain-HX-Fragment", "")
63
64    def get_htmx_action_name(self) -> str:
65        return self.request.headers.get("Plain-HX-Action", "")