From ab860e60746c32ac6dd410aa58294ba751d3e18e Mon Sep 17 00:00:00 2001
From: Edoardo Sabadelli <edoardo@dhis2.org>
Date: Mon, 3 Jun 2024 15:39:31 +0200
Subject: [PATCH] feat: implement dashboard plugin wrapper component

This takes care of offline caching for plugins which works the same in
all analytics apps.
---
 .../DashboardPluginWrapper.js                 | 85 +++++++++++++++++++
 src/index.js                                  |  2 +
 src/modules/getPWAInstallationStatus.js       | 63 ++++++++++++++
 3 files changed, 150 insertions(+)
 create mode 100644 src/components/DashboardPluginWrapper/DashboardPluginWrapper.js
 create mode 100644 src/modules/getPWAInstallationStatus.js

diff --git a/src/components/DashboardPluginWrapper/DashboardPluginWrapper.js b/src/components/DashboardPluginWrapper/DashboardPluginWrapper.js
new file mode 100644
index 000000000..efb85f816
--- /dev/null
+++ b/src/components/DashboardPluginWrapper/DashboardPluginWrapper.js
@@ -0,0 +1,85 @@
+import { useCacheableSection, CacheableSection } from '@dhis2/app-runtime'
+import { CenteredContent, CircularLoader, CssVariables, Layer } from '@dhis2/ui'
+import PropTypes from 'prop-types'
+import React, { useEffect } from 'react'
+import { getPWAInstallationStatus } from '../../modules/getPWAInstallationStatus.js'
+
+const LoadingMask = () => {
+    return (
+        <Layer>
+            <CenteredContent>
+                <CircularLoader />
+            </CenteredContent>
+        </Layer>
+    )
+}
+
+const CacheableSectionWrapper = ({ id, children, isParentCached }) => {
+    const { startRecording, isCached, remove } = useCacheableSection(id)
+
+    useEffect(() => {
+        if (isParentCached && !isCached) {
+            startRecording({ onError: console.error })
+        } else if (!isParentCached && isCached) {
+            // Synchronize cache state on load or prop update
+            // -- a back-up to imperative `removeCachedData`
+            remove()
+        }
+
+        // NB: Adding `startRecording` to dependencies causes
+        // an infinite recording loop as-is (probably need to memoize it)
+        // eslint-disable-next-line react-hooks/exhaustive-deps
+    }, [isParentCached])
+
+    return (
+        <CacheableSection id={id} loadingMask={<LoadingMask />}>
+            {children}
+        </CacheableSection>
+    )
+}
+
+CacheableSectionWrapper.propTypes = {
+    children: PropTypes.node,
+    id: PropTypes.string,
+    isParentCached: PropTypes.bool,
+}
+
+export const DashboardPluginWrapper = ({
+    onInstallationStatusChange,
+    children,
+    cacheId,
+    isParentCached,
+    ...props
+}) => {
+    useEffect(() => {
+        // Get & send PWA installation status now
+        getPWAInstallationStatus({
+            onStateChange: onInstallationStatusChange,
+        }).then(onInstallationStatusChange)
+    }, [onInstallationStatusChange])
+
+    return props ? (
+        <div
+            style={{
+                display: 'flex',
+                height: '100%',
+                overflow: 'hidden',
+            }}
+        >
+            <CacheableSectionWrapper
+                id={cacheId}
+                isParentCached={isParentCached}
+            >
+                {children(props)}
+            </CacheableSectionWrapper>
+            <CssVariables colors spacers elevations />
+        </div>
+    ) : null
+}
+
+DashboardPluginWrapper.propTypes = {
+    cacheId: PropTypes.string,
+    children: PropTypes.func,
+    isParentCached: PropTypes.bool,
+    onInstallationStatusChange: PropTypes.func,
+}
diff --git a/src/index.js b/src/index.js
index 0fb8fe59b..43ca5c83b 100644
--- a/src/index.js
+++ b/src/index.js
@@ -47,6 +47,8 @@ export {
     useCachedDataQuery,
 } from './components/CachedDataQueryProvider.js'
 
+export { DashboardPluginWrapper } from './components/DashboardPluginWrapper/DashboardPluginWrapper.js'
+
 // Api
 
 export { default as Analytics } from './api/analytics/Analytics.js'
diff --git a/src/modules/getPWAInstallationStatus.js b/src/modules/getPWAInstallationStatus.js
new file mode 100644
index 000000000..028cd10f2
--- /dev/null
+++ b/src/modules/getPWAInstallationStatus.js
@@ -0,0 +1,63 @@
+export const INSTALLATION_STATES = {
+    READY: 'READY',
+    INSTALLING: 'INSTALLING',
+}
+
+function handleInstallingWorker({ installingWorker, onStateChange }) {
+    installingWorker.onstatechange = () => {
+        if (installingWorker.state === 'activated') {
+            // ... and update state to 'ready'
+            onStateChange(INSTALLATION_STATES.READY)
+        }
+    }
+}
+
+/**
+ * Gets the current installation state of the PWA features, which is intended
+ * to be reported from this plugin to the parent app to indicate that the
+ * static assets are cached and ready to be accessed locally instead of over
+ * the network.
+ *
+ * Returns either READY, INSTALLING, or `null` for not installed/won't install
+ */
+export async function getPWAInstallationStatus({ onStateChange }) {
+    if (!navigator.serviceWorker) {
+        // Nothing to do here
+        return null
+    }
+
+    const registration = await navigator.serviceWorker.getRegistration()
+    if (!registration) {
+        // This shouldn't happen since this is a PWA app, but return null
+        return null
+    }
+
+    if (registration.active) {
+        return INSTALLATION_STATES.READY
+    }
+    // note that 'registration.waiting' is skipped - it implies there's an active one
+    if (registration.installing) {
+        handleInstallingWorker({
+            installingWorker: registration.installing,
+            onStateChange,
+        })
+        return INSTALLATION_STATES.INSTALLING
+    }
+
+    // It shouldn't normally be possible to get here, but just in case,
+    // listen for installations
+    registration.onupdatefound = () => {
+        // update state for this plugin to 'installing'
+        onStateChange(INSTALLATION_STATES.INSTALLING)
+
+        // also listen for the installing worker to become active
+        const installingWorker = registration.installing
+        if (!installingWorker) {
+            return
+        }
+        handleInstallingWorker({ installingWorker, onStateChange })
+    }
+
+    // and in the mean time, return null to show 'not installed'
+    return null
+}