ensuring content script is running, before sending content

Author: retog

Diff for: package-lock.json

@@ -23,7 +23,7 @@
     "pull-paramap": "^1.2.2",
     "pull-stream": "^3.6.14",
     "ssb-client": "^4.9.0",
-    "web-ext-native-msg": "^4.8.1"
+    "web-ext-native-msg": "^4.8.2"
   },
   "devDependencies": {
     "@rollup/plugin-commonjs": "^17.0.0",

Diff for: package.json

@@ -165,7 +165,7 @@ <h2>Publish your own review of ${item}</h2>
         });
       }
 
-    })
+    }, error => console.log(error))
     setTimeout(() => document.body.classList.add('waited'), 1000)
   </script>
 </body>

Diff for: site/product-review.html

@@ -7,7 +7,35 @@ pull.paraMap = _pullParamap
 
 window.pull = pull
 
+function ping() {
+  window.postMessage({
+    direction: 'from-page-script',
+    action: 'ping'
+  }, '*');
+}
+
+function contentLoaded() {
+  ping()
+  return new Promise((resolve, reject) => {
+    const onMessage = (event) => {
+      if (event.source == window &&
+          event.data &&
+          event.data.direction == 'from-content-script') {
+        if (event.data.action == 'ping') {
+          window.removeEventListener('message', onMessage)
+          resolve()
+        } 
+      }
+    }
+    window.addEventListener('message', onMessage)
+  })
+}
+
 window.connectSsb = function() {
+  return contentLoaded().then(connectSsbNoWait)
+}
+
+function connectSsbNoWait() {
   return new Promise((resolve, reject) => {
 
     let messageDataCallback = null
@@ -24,18 +52,22 @@ window.connectSsb = function() {
     }
 
 
-    window.addEventListener("message", (event) => {
+    window.addEventListener('message', (event) => {
       if (event.source == window &&
           event.data &&
-          event.data.direction == "from-content-script") {
-            const asBuffer = Buffer.from(event.data.message)
-            if (messageDataCallback) {
-              const _messageDataCallback = messageDataCallback
-              messageDataCallback = null
-              _messageDataCallback(null, asBuffer)
-            } else {
-              messageDataBuffer.push(asBuffer)
-            }
+          event.data.direction == 'from-content-script') {
+        if (event.data.action == 'ping') {
+          //ignored ping()
+        } else {
+          const asBuffer = Buffer.from(event.data.message)
+          if (messageDataCallback) {
+            const _messageDataCallback = messageDataCallback
+            messageDataCallback = null
+            _messageDataCallback(null, asBuffer)
+          } else {
+            messageDataBuffer.push(asBuffer)
+          }
+        }
       }
     });
 
@@ -44,14 +76,15 @@ window.connectSsb = function() {
         source(null, function more(end,data) {
           if (end) return done()
           window.postMessage({
-            direction: "from-page-script",
+            direction: 'from-page-script',
             message: data
-          }, "*")
+          }, '*')
           source(null, more)
         })
       }
     }
-    const client = MRPC(function (err, manifest) {
+
+    const clientBuilder = MRPC(function (err, manifest) {
       if (err) reject(err)
       else {
 
@@ -62,7 +95,9 @@ window.connectSsb = function() {
 
         resolve(client)
       }
-    })()
+    })
+
+    const client = clientBuilder()
 
     const onClose = () => {
       console.log('connected to muxrpc server')

Diff for: src/connect-ssb-page-script.js

@@ -16,21 +16,30 @@ const fromPage = function read(abort, cb) {
 }
 
 
+function ping() {
+  window.postMessage({
+    direction: "from-content-script",
+    action: 'ping'
+  }, window.location.origin);
+}
+
 window.addEventListener("message", (event) => {
-  if (event.source == window &&
-      event.data &&
-      event.data.direction == "from-page-script") {
+  if (event.source == window && event.data && event.data.direction == "from-page-script") {
+      if (event.data.action == "ping") {
+        ping()
+      } else {
         //new Uint8Array(event.data.message) is not accepted by muxrpc
         const asBuffer = Buffer.from(event.data.message)
         if (messageDataCallback) {
-          const _messageDataCallback = messageDataCallback
-          messageDataCallback = null
-          _messageDataCallback(null, asBuffer)
+            const _messageDataCallback = messageDataCallback
+            messageDataCallback = null
+            _messageDataCallback(null, asBuffer)
         } else {
           console.log('buffering....')
           messageDataBuffer.push(asBuffer)
         }
-  }
+      }
+    }
 });
 
 const toPage = function sink(done) {
@@ -92,4 +101,5 @@ const toBackgroundScript = function sink(done) {
 }*/
 
 pull(fromPage, toBackgroundScript())
-pull(fromBackgroundScript, toPage())
+pull(fromBackgroundScript, toPage())
+ping()