Debug-mode validator for fragment responses.
Catches silent failure modes where a fragment response would paint a broken page in the browser:
<!DOCTYPEin fragment body (a full page rendered into an outlet).- Duplicate
id="..."for registered shell-region ids (would collide with the live DOM after the swap).
Only active whenAppConfig.debug=True; auto-registered during
_collect_builtin_middlewarewhen an OOB registry is present. Warns
by default;strict=Trueraises instead for CI enforcement.
middleware.debug_fragment_validator
| Name | Type | Default | Description |
|---|---|---|---|
type
|
|
— | |
qualified_name
|
|
— | |
element_type
|
|
— | |
description
|
|
— | |
source_file
|
|
— | |
line_number
|
|
— | |
is_autodoc
|
|
— | |
autodoc_element
|
|
— | |
_autodoc_template
|
|
— | |
_autodoc_url_path
|
|
— | |
_autodoc_page_type
|
|
— | |
title
|
|
— | |
doc_content_hash
|
|
— |
Symbols on this page
Raised byDebugFragmentValidatorin strict mode when a
fragment response leaks full-page markup or duplicate ids.
Middleware that inspects fragment responses for breakage patterns.
Only inspects bufferedResponse objects with text/htmlcontent
whenrender_intent == "fragment" (or "unknown"on an…
Countid="target_id" and id='target_id'occurrences.
True for app-shell boosted responses meant to be narrowed by hx-select.
The browser owns the inheritedhx-select="#page-content"attribute; it is not sent as a…
FragmentValidationError
class
Raised byDebugFragmentValidatorin strict mode when a
fragment response leaks full-page markup or duplicate ids.
DebugFragmentValidator
class
Middleware that inspects fragment responses for breakage patterns.
Only inspects bufferedResponse objects with text/htmlcontent
whenrender_intent == "fragment" (or "unknown"on an htmx
request, matchingHTMLInject's skip rule).
Streaming responses are skipped — buffering them would defeat the point of streaming and the body is rarely available as a single string anyway.
_count_id_occurrences
function
def _count_id_occurrences(body: str, target_id: str) -> intCountid="target_id" and id='target_id'occurrences.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
body
|
str
|
— | |
target_id
|
str
|
— |
_is_selectable_shell_outlet_response
function
def _is_selectable_shell_outlet_response(body: str, request: Request) -> boolTrue for app-shell boosted responses meant to be narrowed by hx-select.
The browser owns the inheritedhx-select="#page-content"attribute; it
is not sent as a request header. In debug mode this validator sees the
pre-selection response, so a correctly selectable shell-outlet response can
look like a full document with duplicate shell-region ids. Treat the
canonical app-shell shape as valid when the response contains the selector
target htmx will extract.
Parameters
| Name | Type | Default | Description |
|---|---|---|---|
body
|
str
|
— | |
request
|
Request
|
— |