rdlowrey · August 29, 2015 14:17 · Mar 17, 2015 · Mar 17, 2015 · Mar 17, 2015 · Mar 17, 2015
diff --git a/yield-from-example.php b/yield-from-example.php
@@ -8,7 +8,7 @@ function myHttpHandler(Request $request, Response $response) {
 
     if ($session->hasValue('isLoggedIn')) {
         // pass the individual promises from generateHttpBody() through using `yield from`
-        // when generateBody() finishes we get its return result in $body
+        // when generateHttpBody() finishes we get its return result in $body
         $rawHtmlBody = yield from generateHttpBody($request);
     } else {
         $response->setStatus(301);

diff --git a/yield-from-example.php b/yield-from-example.php
@@ -7,7 +7,7 @@ function myHttpHandler(Request $request, Response $response) {
     $session = yield loadSessionFromRequest($request);
 
     if ($session->hasValue('isLoggedIn')) {
-        // pass the individual promises from generateBody() through using `yield from`
+        // pass the individual promises from generateHttpBody() through using `yield from`
         // when generateBody() finishes we get its return result in $body
         $rawHtmlBody = yield from generateHttpBody($request);
     } else {

diff --git a/yield-from-example.php b/yield-from-example.php
@@ -9,14 +9,14 @@ function myHttpHandler(Request $request, Response $response) {
     if ($session->hasValue('isLoggedIn')) {
         // pass the individual promises from generateBody() through using `yield from`
         // when generateBody() finishes we get its return result in $body
-        $body = yield from generateHttpBody($request);
+        $rawHtmlBody = yield from generateHttpBody($request);
     } else {
         $response->setStatus(301);
         $response->setHeader("Location", "http://domain.com/login");
-        $body = '';
+        $rawHtmlBody = '';
     }
 
-    $response->send($body);
+    $response->send($rawHtmlBody);
 }
 
 function generateHttpBody(Request $request, Session $session) {

diff --git a/yield-from-example.php b/yield-from-example.php
@@ -0,0 +1,39 @@
+<?php
+
+function myHttpHandler(Request $request, Response $response) {
+    // async function that returns a promise
+    // we use yield to wait for that promise to resolve then resume here
+    // if there's some kind of error it will be thrown into our generator
+    $session = yield loadSessionFromRequest($request);
+
+    if ($session->hasValue('isLoggedIn')) {
+        // pass the individual promises from generateBody() through using `yield from`
+        // when generateBody() finishes we get its return result in $body
+        $body = yield from generateHttpBody($request);
+    } else {
+        $response->setStatus(301);
+        $response->setHeader("Location", "http://domain.com/login");
+        $body = '';
+    }
+
+    $response->send($body);
+}
+
+function generateHttpBody(Request $request, Session $session) {
+    // returns a promise; pause here until the promise resolves.
+    // this promise is passed through transparently inside myHttpHandler()
+    // because we used `yield from` there.
+    $user = yield loadUserFromDatabase($session->getValue('userId'));
+
+    // Another promise -- again, this is passed through transparently
+    // because we used `yield from` in myHttpHandler()
+    $template = yield loadTemplateFromRedis($request->getUriPath());
+
+    // ... do some stuff here to set template values ... //
+
+    return $rawHtmlBody;
+}
+
+// And above this layer in the HTTP server code:
+// $promise = coroutine(myHttpHandler($request, $response));
+// $promise->when(...); // we know the response completed here