Glossary#

Terms used throughout the next.dj documentation.

action#: A registered entry point for a form POST. Form classes register automatically through __init_subclass__ with a snake_case name derived from the class name. Form-less functions register through @action("name"). The framework derives a stable dispatch URL from the action name.
asset#: A file registered with the static pipeline. Has a stem, an extension, and an owner (page, layout, or component).
asset kind#: A combination of extension and renderer that decides how an asset becomes HTML. Bundled kinds are css, js, and module.
backend#: A subsystem implementation registered through NEXT_FRAMEWORK. Used for the router, the components backend, the static backend chain, and the form action chain.
collector#: The request scoped object that accumulates assets touched by the current render.
collector slot#: A named collection inside the static collector. {% collect_styles %} emits the styles slot, {% collect_scripts %} emits the scripts slot.
component#: A reusable template fragment under the components root. Has a template and optional Python module.
ComponentWidget#: A form widget that renders a field through a registered next.dj component instead of a Django widget template. One field maps to one component, and the component owns the markup.
context function#: A Python callable decorated with @context("key") that publishes a value to the template scope.
DI marker#: A typed annotation or default-value object that asks the resolver for a specific source of data. An annotation marker is written in the type position, for example param: DUrl[int], and covers DUrl, DQuery, and DForm. A default-value marker is written as the parameter default, for example param: str = Context(), and covers Context and Depends.
discovery#: The filesystem walk that builds the asset registry, the components registry, and the page registry at startup.
dispatch#: The pipeline that turns a form submission into a handler invocation. A failed validation skips the handler and re-renders the origin page instead.
dynamic permission hook#: A per-request access check declared on a form, check_permissions for the view level and has_object_permission for the bound instance. Both resolve through the dependency injector and return PermissionOutcome, the bool | HttpResponse | None alias. They run as an additive layer after the static guard. See Dynamic permission hooks.
form wizard backend#: The draft-persistence contract for a FormWizard, a FormWizardBackend subclass that stores each step’s cleaned data between requests. Selected through NEXT_FRAMEWORK["FORM_WIZARD_BACKEND"], with the bundled SessionFormWizardBackend as the default and CacheFormWizardBackend as the cache-backed alternative.
FormSpec#: A frozen dataclass that describes a form layout. Used to render forms in custom templates.
FormWizard#: A multi-step form that routes a sequence of step forms across requests. Steps are declared as (name, FormClass) tuples in Meta.steps, and done runs after the final step validates.
framework island#: A Vue or React root mounted into one element of an otherwise server-rendered page. An adapter mounts it through Next.partial.onMount or the next:mounted event and unmounts it on next:removed, so a partial update never leaks its listeners. See Framework islands.
guard#: The access requirement declared on an action through Meta.login_required and Meta.permission_required, or the matching @action keywords. Stored as an ActionGuard on the registry metadata and enforced before the form is built. See Access guards.
inherit_context#: The inherit_context=True flag on @context in page.py. Publishes the context value to every descendant page under that directory, not only to the page that declares it.
JS context policy#: Algorithm class that resolves duplicate serialised keys for window.Next.context, distinct from the JS context serializer that encodes the values. Selected through JS_CONTEXT_POLICY inside static backend OPTIONS, see JavaScript context.
JS context serializer#: Implementations of next.static.JsContextSerializer that encode values for window.Next.context, distinct from the JS context policy that resolves duplicate keys. Distinct from frozen form specs in next.forms.serializers.
layer#: A server-initiated overlay stacked above the current page, opened by the layer.open patch verb or a data-next-layer link. The client runtime hosts each layer in its own <dialog> element and closes the top layer on accept, dismissal, or Back.
layout#: A layout.djx file in an ancestor directory. Wraps every descendant page.
manager#: The singleton orchestrator for one subsystem. Examples include page, components_manager, router_manager, form_action_manager.
morph#: The default patch verb. Reconciles the target element in place instead of replacing it, and data-next-key lets it reuse the node a keyed child already owns.
multi-project layout#: Multiple Django applications or explicit DIRS entries each contributing page trees while optionally sharing component directories through COMPONENT_BACKENDS. See Multi-project setup.
NextScriptBuilder#: Constructs the next.min.js tag, preload link, and Next._init shell. Controlled through NEXT_FRAMEWORK["NEXT_JS_OPTIONS"].
origin page#: The page that rendered a form. Identified at dispatch time by resolving the hidden _next_form_origin URL path against the URLconf.
outcome#: The ActionOutcome dataclass a form action backend produces from a dispatch, shaped into the HTTP response by shape_response. See Action backends.
page#: A directory under the page root with a page.py, or a virtual route with only a template.djx.
page root#: A directory that the router walks for page discovery. Comes from APP_DIRS and DIRS in PAGE_BACKENDS.
partial request#: A request the client runtime marks with the X-Next-Request header. is_partial_request detects it on the server, so a handler can answer with a patch envelope instead of a redirect.
patch#: One addressed DOM operation inside a patch envelope. Carries a verb such as morph or remove, a target selector, and optional HTML.
patch envelope#: The wire object of a partial response. Carries the asset version, the ordered patch ops, the co-located assets of the rendered targets, and the machine-readable form meta.
provider#: A class that produces a value for a parameter. Implements can_handle and resolve.
re-render#: The dispatch path that re-renders the origin page after a failed form validation.
request cache#: The dependency cache that lives on the request between context functions, components, and form re-render.
resolver#: The singleton DependencyResolver that fills parameters from providers.
route name#: The Django URL name string inside the next namespace (app_name on next.urls). Values come from NEXT_FRAMEWORK["URL_NAME_TEMPLATE"], default "page_{name}", where {name} is derived from the normalized filesystem path. Reverse from templates as {% url 'next:page_notes_id' id=note.id %} or from Python through URL reversing.
scope#: The keying rule for an action name, page or shared. A page-scoped action is keyed to the absolute path of its declaring page.py or component.py, while a shared action is keyed to its dotted module name and is reachable project-wide. The resulting key is the scope key that the UID hashes together with the action name. See Actions.
ScriptInjectionPolicy#: Controls whether the framework injects the runtime bundle automatically (AUTO), skips injection (DISABLED), or leaves placement to your templates (MANUAL).
signal#: A Django signal emitted by one subsystem. Subscribers react without subclassing.
slot#: A named area inside a component template filled with caller content through the block form of {% component %}.
stem#: The filename without the extension. The recognised stem is component for a component file, layout for a layout file, and template for a page template file. There is no page stem.
strategy#: A swappable algorithm such as DedupStrategy for static deduplication.
template loader#: A TemplateLoader subclass registered through NEXT_FRAMEWORK["TEMPLATE_LOADERS"] that supplies template text for a page.py path. See Add a custom template loader.
UID#: The 16 character hash of an action’s scope key and name that becomes part of the dispatch URL.
virtual route#: A directory with only template.djx and no page.py. No Python module is invoked for the route itself, but ancestor layout.djx files still wrap it and co-located static assets are still collected.
zone#: A named slice of a page template wrapped in {% zone %}. The server re-renders the slice standalone, and patches address it by its name.

Glossary#

See also#