def message(request: HttpRequest, component_name: str = None) -> JsonResponse:
"""
Endpoint that instantiates the component and does the correct action
(set an attribute or call a method) depending on the JSON payload in the body.
Args:
param request: HttpRequest for the function-based view.
param: component_name: Name of the component, e.g. "hello-world".
Returns:
`JsonRequest` with the following structure in the body:
{
"id": component_id,
"dom": html, // re-rendered version of the component after actions in the payload are completed
"data": {}, // updated data after actions in the payload are completed
"errors": {}, // form validation errors
"return": {}, // optional return value from an executed action
"parent": {}, // optional representation of the parent component
}
"""
assert component_name, "Missing component name in url"
component_request = ComponentRequest(request, component_name)
json_result = _handle_component_request(request, component_request)
return JsonResponse(json_result)
def _handle_component_request(
request: HttpRequest, component_request: ComponentRequest
) -> Dict:
"""
Process a `ComponentRequest` by adding it to the cache and then either:
- processing all of the component requests in the cache and returning the resulting value if
it is the first component request for that particular component name + component id combination
- return a `dict` saying that the request has been queued
Args:
param request: HttpRequest for the function-based view.
param: component_request: Component request to process.
Returns:
`dict` with the following structure:
{
"id": component_id,
"dom": html, // re-rendered version of the component after actions in the payload are completed
"data": {}, // updated data after actions in the payload are completed
"errors": {}, // form validation errors
"return": {}, // optional return value from an executed action
"parent": {}, // optional representation of the parent component
}
"""
# If serial isn't enabled or the wrong cache, just process the request like normal
if not get_serial_enabled():
return _process_component_request(request, component_request)
cache = caches[get_cache_alias()]
# Add the current request `ComponentRequest` to the cache
queue_cache_key = f"unicorn:queue:{component_request.id}"
component_requests = cache.get(queue_cache_key) or []
# Remove `request` from `ComponentRequest` before caching because it is not pickleable
component_request.request = None
component_requests.append(component_request)
cache.set(
queue_cache_key,
component_requests,
timeout=get_serial_timeout(),
)
if len(component_requests) > 1:
original_epoch = component_requests[0].epoch
return {
"queued": True,
"epoch": component_request.epoch,
"original_epoch": original_epoch,
}
return _handle_queued_component_requests(
request, component_request.name, queue_cache_key
)
def _process_component_request(
request: HttpRequest, component_request: ComponentRequest
) -> Dict:
"""
Process a `ComponentRequest`:
1. construct a Component view
2. set all of the properties on the view from the data
3. execute the type
- update the properties based on the payload for "syncInput"
- call the method specified for "callMethod"
4. validate any fields specified in a Django form
5. construct a `dict` that will get returned in a `JsonResponse` later on
Args:
param request: HttpRequest for the function-based view.
param: component_request: Component request to process.
Returns:
`dict` with the following structure:
{
"id": component_id,
"dom": html, // re-rendered version of the component after actions in the payload are completed
"data": {}, // updated data after actions in the payload are completed
"errors": {}, // form validation errors
"return": {}, // optional return value from an executed action
"parent": {}, // optional representation of the parent component
}
"""
component = UnicornView.create(
component_id=component_request.id,
component_name=component_request.name,
request=request,
)
# Get a deepcopy of the data passed in to determine what fields are updated later
original_data = copy.deepcopy(component_request.data)
# Set component properties based on request data
for (property_name, property_value) in component_request.data.items():
set_property_from_data(component, property_name, property_value)
component.hydrate()
validate_all_fields = False
is_reset_called = False
is_refresh_called = False
return_data = None
partials = []
for action in component_request.action_queue:
if action.partial:
partials.append(action.partial)
else:
partials = action.partials
if action.action_type == "syncInput":
sync_input.handle(component_request, component, action.payload)
elif action.action_type == "callMethod":
(
component,
_is_refresh_called,
_is_reset_called,
_validate_all_fields,
return_data,
) = call_method.handle(component_request, component, action.payload)
is_refresh_called = is_refresh_called | _is_refresh_called
is_reset_called = is_reset_called | _is_reset_called
validate_all_fields = validate_all_fields | _validate_all_fields
else:
raise UnicornViewError(f"Unknown action_type '{action.action_type}'")
component.complete()
# Re-load frontend context variables to deal with non-serializable properties
component_request.data = orjson.loads(component.get_frontend_context_variables())
# Get set of attributes that should be marked as `safe`
safe_fields = []
if hasattr(component, "Meta") and hasattr(component.Meta, "safe"):
if isinstance(component.Meta.safe, Sequence):
for field_name in component.Meta.safe:
if field_name in component._attributes().keys():
safe_fields.append(field_name)
# Mark safe attributes as such before rendering
for field_name in safe_fields:
value = getattr(component, field_name)
if isinstance(value, str):
setattr(component, field_name, mark_safe(value))
# Send back all available data for reset or refresh actions
updated_data = component_request.data
if not is_reset_called:
if not is_refresh_called:
updated_data = {}
for key, value in original_data.items():
if value != component_request.data.get(key):
updated_data[key] = component_request.data.get(key)
if validate_all_fields:
component.validate()
else:
component.validate(model_names=list(updated_data.keys()))
# Pass the current request so that it can be used inside the component template
rendered_component = component.render(request=request)
component.rendered(rendered_component)
cache = caches[get_cache_alias()]
try:
cache.set(component.component_cache_key, get_cacheable_component(component))
except UnicornCacheError as e:
logger.warning(e)
partial_doms = []
if partials and all(partials):
soup = BeautifulSoup(rendered_component, features="html.parser")
for partial in partials:
partial_found = False
only_id = False
only_key = False
target = partial.get("target")
if not target:
target = partial.get("key")
if target:
only_key = True
if not target:
target = partial.get("id")
if target:
only_id = True
assert target, "Partial target is required"
if not only_id:
for element in soup.find_all():
if (
"unicorn:key" in element.attrs
and element.attrs["unicorn:key"] == target
):
partial_doms.append({"key": target, "dom": str(element)})
partial_found = True
break
if not partial_found and not only_key:
for element in soup.find_all():
if "id" in element.attrs and element.attrs["id"] == target:
partial_doms.append({"id": target, "dom": str(element)})
partial_found = True
break
res = {
"id": component_request.id,
"data": updated_data,
"errors": component.errors,
"calls": component.calls,
"checksum": generate_checksum(orjson.dumps(component_request.data)),
}
if partial_doms:
res.update({"partials": partial_doms})
else:
hash = generate_checksum(rendered_component)
if (
component_request.hash == hash
and (not return_data or not return_data.value)
and not component.calls
):
raise RenderNotModified()
# Make sure that partials with comments or blank lines before the root element only return the root element
soup = BeautifulSoup(rendered_component, features="html.parser")
rendered_component = str(get_root_element(soup))
res.update(
{
"dom": rendered_component,
"hash": hash,
}
)
if return_data:
res.update(
{
"return": return_data.get_data(),
}
)
if return_data.redirect:
res.update(
{
"redirect": return_data.redirect,
}
)
if return_data.poll:
res.update(
{
"poll": return_data.poll,
}
)
parent_component = component.parent
if parent_component:
# TODO: Should parent_component.hydrate() be called?
parent_frontend_context_variables = loads(
parent_component.get_frontend_context_variables()
)
parent_checksum = generate_checksum(dumps(parent_frontend_context_variables))
parent = {
"id": parent_component.component_id,
"checksum": parent_checksum,
}
if not partial_doms:
parent_dom = parent_component.render()
component.parent_rendered(parent_dom)
try:
cache.set(
parent_component.component_cache_key,
get_cacheable_component(parent_component),
)
except UnicornCacheError as e:
logger.warning(e)
parent.update(
{
"dom": parent_dom,
"data": parent_frontend_context_variables,
"errors": parent_component.errors,
}
)
res.update({"parent": parent})
return res