Updated async to support chained maps

peterjwest · May 1, 2012 · 085918a · 085918a
1 parent 74a6248
commit 085918a
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Showing 2 changed files with 39 additions and 5 deletions.
diff --git a/async.js b/async.js
@@ -5,6 +5,7 @@
 // TODO
 // Add fail event
 // Prevent multiple firing?
+// Make it work for falsey values
 
 var async = exports || {};
 var nothing = function() {};
@@ -17,7 +18,8 @@ async.promise = function(fn) {
     var promise = {};
     promise.next = {
       success: function() {
-        promise.succeeded = arguments[0];
+        promise.succeeded = true;
+        promise.result = arguments[0];
         if (promise.success) promise.success();
       },
       fail: function() { promise.failed = arguments[0]; },
@@ -27,14 +29,24 @@ async.promise = function(fn) {
     // Adds then method to the promise
     promise.then = function(success, fail) {
       var newPromise = create();
-
       promise.success = function() {
-        var value = success.call(newPromise.next, promise.succeeded);
+        success.call(newPromise.next, promise.result);
       };
       if (promise.succeeded) promise.success();
       return newPromise;
     };
 
+    // Adds map method to the promise
+    promise.map = function(success, fail) {
+      var newPromise = create();
+      promise.success = function() {
+        async.map(promise.result, success).then(function(result) {
+          newPromise.next.success(result);
+        });
+      };
+      if (promise.succeeded) promise.success();
+      return newPromise;
+    };
     return promise;
   };
 

diff --git a/async_test.js b/async_test.js
@@ -12,7 +12,8 @@ async.promise(function() {
   var next = this;
   setTimeout(function() { next.success(value); }, 10);
 })
-.then(function(f) { console.log(f); });
+.then(function(f) { console.log(f); this.success(); })
+.then(function() { console.log("--------------"); });
 
 //Runs a function with asynchronous behaviour on an array of items
 async.map([1,2,3,4,5,6], function(item, i) {
@@ -21,4 +22,25 @@ async.map([1,2,3,4,5,6], function(item, i) {
     next.success(item-1);
   }, 10);
 })
-.then(function(i) { console.log(i.join(",")); });
+.then(function(i) { console.log(i.join(",")); this.success(); })
+.then(function() { console.log("--------------"); });
+
+//Runs a function with asynchronous behaviour on an array of items, twice
+async.map([1,2,3], function(item, i) {
+  var next = this;
+  setTimeout(function() {
+    next.success(item);
+  }, 50);
+})
+.map(function(item) { console.log(item); this.success(); })
+.then(function() { console.log("--------------"); })
+
+//Runs a function with asynchronous behaviour on an array of items, twice
+async.promise(function() {
+  var next = this;
+  setTimeout(function() {
+    next.success([4,5,6]);
+  }, 180);
+})
+.map(function(item) { console.log(item); this.success(item); })
+.map(function(item) { console.log(item); this.success(); })