PKG -- [fcl] Fixed android polling (#1703)

* PKG -- [fcl] Fixed android polling * DOC -- [fcl] add comments * DOC -- [fcl] add comments
onflow · Jun 27, 2023 · 8dcb70c · 8dcb70c
1 parent fefb578
commit 8dcb70c
Show file tree

Hide file tree

Showing 3 changed files with 32 additions and 8 deletions.
diff --git a/packages/fcl/src/current-user/exec-service/strategies/http-post.js b/packages/fcl/src/current-user/exec-service/strategies/http-post.js
@@ -26,25 +26,44 @@ export const getExecHttpPost = (execLocal) => async({service, body, config, opts
   } else if (resp.status === "REDIRECT") {
     return resp
   } else if (resp.status === "PENDING") {
+
+    // these two flags are required to run polling one more time before it stops
     var canContinue = true
+    var shouldContinue = true
+
     const [_, unmount] = await execLocal(
       normalizeLocalView(resp.local),
       {
         serviceEndpoint,
-        onClose: () => (canContinue = false)
+        onClose: () => (shouldContinue = false)
       }
     )
 
     const close = () => {
       try {
         unmount()
-        canContinue = false
+        shouldContinue = false
       } catch (error) {
         console.error("Frame Close Error", error)
       }
     }
+    /**
+     * this function is run once per poll call.
+     * Offsetting canContinue flag to make sure that
+     * the polling is performed one extra time after canContinue flag is set to false
+     * to prevent halting on Android when a browser calls window.close
+     * before FCL receives a successful result from polling
+     *
+     * @returns {boolean} 
+     */ 
+    const checkCanContinue = () => {
+      const offsetCanContinue = canContinue
+      canContinue = shouldContinue
+
+      return offsetCanContinue
+    }
 
-    return poll(resp.updates, () => canContinue)
+    return poll(resp.updates, checkCanContinue)
       .then(serviceResponse => {
         close()
         return serviceResponse

diff --git a/packages/fcl/src/current-user/exec-service/strategies/utils/poll.js b/packages/fcl/src/current-user/exec-service/strategies/utils/poll.js
@@ -24,9 +24,10 @@ const serviceBody = service => {
   return undefined
 }
 
-export async function poll(service, canContinue = () => true) {
+export async function poll(service, checkCanContinue = () => true) {
   invariant(service, "Missing Polling Service", {service})
-  if (!canContinue()) throw new Error("Externally Halted")
+  const canContinue = checkCanContinue()
+  if (!canContinue) throw new Error("Externally Halted")
 
   let resp
   try {
@@ -35,7 +36,7 @@ export async function poll(service, canContinue = () => true) {
       document.visibilityState === "hidden"
     ) {
       await new Promise(r => setTimeout(r, 500))
-      return poll(service, canContinue)
+      return poll(service, checkCanContinue)
     }
 
     resp = await fetchService(service, {
@@ -52,6 +53,6 @@ export async function poll(service, canContinue = () => true) {
       throw new Error(`Declined: ${resp.reason || "No reason supplied."}`)
     default:
       await new Promise(r => setTimeout(r, 500))
-      return poll(resp.updates, canContinue)
+      return poll(resp.updates, checkCanContinue)
   }
 }
diff --git a/packages/fcl/src/utils/react-native/render-browser.js b/packages/fcl/src/utils/react-native/render-browser.js
@@ -4,7 +4,11 @@ export function renderBrowser(src, opts = {}) {
   const webbrowser = WebBrowser.openAuthSessionAsync(src.toString())
 
   const unmount = () => {
-    WebBrowser.dismissAuthSession()
+    try {
+      WebBrowser.dismissAuthSession()
+    } catch (error) {
+      console.log(error)
+    }
   }
 
   // Call onClose when the webbrowser is closed