Django views, is_spa_enabled feature flag, URL mapping, login flow, and template serving for the SPA.

Backend

Architecture Overview

The SPA backend is entirely within livehealthapp (Django/Py2). It handles three responsibilities: controlling which labs get SPA vs. legacy builds via a Redis feature flag, serving the SPA HTML template, and routing login redirects to the correct URL.

System Design Diagram

The `is_spa_enabled()` Function

Source: labs/cacheFunction.py

This is the central feature flag that controls SPA vs. legacy mode. It's a simple Redis cache lookup:

def is_spa_enabled(lab_id):
    """
    Flag will be used to get/set SPA (Single Page App).
    """
    if not lab_id:
        return False

    cache_key = "is_spa_enabled_{lab_id}".format(lab_id=lab_id)
    return cache.get(cache_key) or False

Key Characteristics

Property	Value
Storage	Redis (Django cache backend)
Key format	`is_spa_enabled_{lab_id}`
Default	`False` (absent key = SPA disabled)
TTL	No expiry — persists until explicitly deleted
Set by	Account creation (`selfserved/account_creation/account.py`) or manually via Redis CLI

CrelioDashboardView

Source: livehealth_4/views.py

This is the Django view that serves the SPA HTML:

class CrelioDashboardView(View):

    def get(self, request, *args, **kwargs):
        lab_id = request.session.get('labId')
        is_support_login = request.session.get('isSupportLogin')
        if not lab_id or not (is_spa_enabled(lab_id) or is_support_login):
            return HttpResponseRedirect('/')

        rendered_html = render(
            request,
            'build_assets/dashboard/build/crelio-dashboard.html'
        )
        return prepare_favicon_change_response(request, rendered_html)

Access Control

Check	Purpose
`lab_id` must exist	Rejects unauthenticated requests
`is_spa_enabled(lab_id)` OR `is_support_login`	Only SPA-enabled labs or support users can access
Falls back to `HttpResponseRedirect('/')`	Non-SPA labs hitting `/crelio-dashboard/` are sent to the login page

Support users (isSupportLogin = True) always get access to the SPA, regardless of whether the lab has is_spa_enabled set. This is intentional — support needs the unified view for faster debugging.

The login flow determines the user's loginURL based on their role and SPA status. This happens in multiple places across the codebase.

Session Helpers

Source: logins/utils/session_helpers.py

The session builder determines where a user lands after login:

# For operations staff
login_url = "/crelio-dashboard/#/operation" if is_spa_enabled(user.labId) else '/waitingList/'

# For accession staff
login_url = "/crelio-dashboard/#/accession/" if is_spa_enabled(user.labId) else "/sample-accession/"

# For finance staff
login_url = "/crelio-dashboard/#/finance/dashboard" if is_spa_enabled(user.labId) else "/finance-new/#/dashboard"

# For registration staff
login_url = "/crelio-dashboard/#/registration/directRegistration" if is_spa_enabled(user.labId) else "/billing/#directRegistration"

# For inventory staff
login_url = "/crelio-dashboard/#/inventory/inventory-dashboard" if is_spa_enabled(user.labId) else "/inventory-v5/"

The is_spa_enabled flag is also stored in the session itself for frontend and template access:

# In session_helpers.py - get_lab_user_session()
"is_spa_enabled": is_spa_enabled(getattr(user, "labId_id", False)) or False,

SPA URL Mapper

Source: livehealth_4/decorators/utils.py

SPA_URL_MAPPER = {
    "/accountOverview/": "/crelio-dashboard/#/admin/account-overview",
    "/billing/#directRegistration": "/crelio-dashboard/#/registration/",
    "/waitingList/": "/crelio-dashboard/#/operation",
    "/finance-new/#/dashboard": "/crelio-dashboard/#/finance/",
    "/sample-accession/": "/crelio-dashboard/#/accession/",
    "/inventory-v5/": "/crelio-dashboard/#/inventory",
    "/crm/dashboard/": "/crelio-dashboard/#/crm",
    "/referral-management/": "/crelio-dashboard/#/finance/referral-management/referral-list",
    "/adminTestList-v5/#/admin/account-overview": "/crelio-dashboard/#/admin/account-overview"
}

This dictionary maps every legacy module URL to its SPA equivalent. It's used by the mapped_spa_url() function during login and lab-switching.

Version Detection — v4 vs v5

Before any SPA logic runs, the system first determines whether the lab is on v4 (legacy app) or v5 (React builds). This is controlled by two session values:

Condition	Version	UI
`reactVersionAccess == 1`	v5	React single-build modules
`newRegistrationPage == 3`	v5	React registration and accession builds
Neither of the above	v4	Legacy app

v5 is the prerequisite for SPA. A lab must be on v5 before it can be SPA-enabled. Labs on v4 always receive the legacy app regardless of the is_spa_enabled flag.

Within v5, the SPA is an additional opt-in controlled by the is_spa_enabled Redis flag:

Version	`is_spa_enabled`	What the user gets
v4	N/A	Legacy app
v5	`False` (or absent)	React single-build modules (one HTML per module)
v5	`True`	SPA — unified `crelio-dashboard.html` for all modules

The `mapped_spa_url()` Function

Source: livehealth_4/decorators/version_decorator.py

This function translates legacy loginURL values to SPA URLs during lab switching. It checks version first, then SPA eligibility:

def mapped_spa_url(session, lab_id, use_spa_routing=False):
    if not session or not lab_id:
        return "/"

    login_url = session.get('loginURL')
    react_version_access = session.get("reactVersionAccess")
    new_registration_page = session.get("newRegistrationPage")
    is_support_login = session.get('isSupportLogin')

    # Step 1: Version check — v5 non-SPA builds return URL as-is
    # reactVersionAccess == 1 OR newRegistrationPage == 2 → v5 but not SPA-eligible
    if any([react_version_access == 1, new_registration_page == 2]):
        return login_url

    # Step 2: Lab switch with SPA enabled
    if use_spa_routing and is_spa_enabled(lab_id):
        return SPA_URL_MAPPER.get(login_url) or login_url

    # Step 3: Normal login — check if v5 SPA-eligible
    # reactVersionAccess == 2 OR newRegistrationPage == 3 → v5 SPA-eligible
    if is_spa_enabled(lab_id) and (
        react_version_access == 2 or
        new_registration_page == 3
    ) or is_support_login:
        return SPA_URL_MAPPER.get(login_url) or login_url

    return login_url

Decision Tree

The `asset_provider` Decorator

Source: livehealth_4/decorators/version_decorator.py

For legacy module views that support multiple build versions (v4 Jinja templates vs. v5 React builds), the asset_provider decorator determines which template to render:

@access_labUser()
@asset_provider("accession")
def sample_accession_v4_view(request, template):
    rendered_html = render(request, template, {...})
    return prepare_favicon_change_response(request, rendered_html)

Module	Version Key	Version 0-2	Version 3-4
Registration	`defaultRegistrationPage`	Jinja templates	`build_assets/dashboard/build/registration.html`
Accession	`defaultRegistrationPage`	Jinja templates	`build_assets/dashboard/build/accession.html`
Operations	`reactVersionAccess`	Jinja templates	`build_assets/dashboard/build/operations.html`
Finance	`reactVersionAccess`	Jinja templates	`build_assets/dashboard/build/finance.html`

The asset_provider handles v4 → v5 template resolution for the legacy single-build mode. It does not handle SPA routing — that's done via the login flow and CrelioDashboardView.

Template Serving — SPA vs. Legacy

Aspect	SPA Mode	Legacy Single-Build Mode
Template served	`crelio-dashboard.html`	`registration.html`, `operations.html`, etc.
Django views hit	Single `CrelioDashboardView`	Module-specific views (`registration_view_v5`, etc.)
Module switching	Client-side hash route change	Full browser navigation → Django → new template
Static assets	Single JS bundle (with code-split chunks)	Per-module JS bundles
Public path	`/static/build_assets/CrelioDashboard/build/`	`/static/build_assets/dashboard/build/`

Key Backend Locations

File	Purpose
`labs/cacheFunction.py`	`is_spa_enabled()` — Redis feature flag lookup
`livehealth_4/views.py`	`CrelioDashboardView` — serves `crelio-dashboard.html`
`livehealth_4/decorators/version_decorator.py`	`mapped_spa_url()`, `asset_provider` decorator
`livehealth_4/decorators/utils.py`	`SPA_URL_MAPPER`, `ASSET_MAPPER` dictionaries
`logins/utils/session_helpers.py`	Login URL resolution with `is_spa_enabled` checks
`logins/views.py`	Login view with SPA session setup
`selfserved/account_creation/account.py`	Sets `is_spa_enabled` for newly created labs

Backend

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