回答編集履歴

追加

2017/11/23 10:24

投稿

HayatoKamono

スコア2415

test CHANGED Viewed

@@ -1,6 +1,8 @@
+# 1
 ![イメージ説明](169890ce9946de02b6a79a1a6c154683.gif)
-[https://teratail.storage.googleapis.com/uploads/contributed_images/169890ce9946de02b6a79a1a6c154683.gif](https://teratail.storage.googleapis.com/uploads/contributed_images/169890ce9946de02b6a79a1a6c154683.gif)
+[アニメーションGIF](https://teratail.storage.googleapis.com/uploads/contributed_images/169890ce9946de02b6a79a1a6c154683.gif)
@@ -153,3 +155,141 @@
 ```
+#2
+![イメージ説明](350cb20d5f1b095dabc37153f4e3e8db.gif)
+[アニメーションGIF](https://teratail.storage.googleapis.com/uploads/contributed_images/350cb20d5f1b095dabc37153f4e3e8db.gif)
+```
+const fakeAjax = (fileName, callback) => {
+	const MAX = 5000;
+	const MIN = 1000;
+	const delay = Math.floor(Math.random() * (MAX - MIN) + MIN);
+	const responseMockData = {
+		"1.txt": "1st request",
+		"2.txt": "2nd request",
+		"3.txt": "3rd request",
+		"4.txt": "4th request",
+		"5.txt": "5th request"
+	};
+	setTimeout(() => {
+		callback(responseMockData[fileName]);
+	}, delay);
+}
+const output = console.log.bind(this);
+const getFile = (fileName) => {
+	let memoizedResult;
+	let memoizedCallback;
+	fakeAjax(fileName, (response) => {
+		if (memoizedCallback) {
+			return memoizedCallback(response);
+		}
+		memoizedResult = response;
+	});
+	return (callback) => {
+		if (memoizedResult) {
+			return callback(memoizedResult);
+		}
+		 memoizedCallback = callback;
+	};
+}
+const getFile1 = getFile('1.txt');
+const getFile2 = getFile('2.txt');
+const getFile3 = getFile('3.txt');
+const getFile4 = getFile('4.txt');
+const getFile5 = getFile('5.txt');
+getFile1(resultForFile1 => {
+	output(resultForFile1);
+	getFile2(resultForFile2 => {
+		output(resultForFile2);
+		getFile3(resultForFile3 => {
+			output(resultForFile3);
+			getFile4(resultForFile4 => {
+				output(resultForFile4);
+				getFile5(resultForFile5 => {
+					output(resultForFile5);
+					output('all done!');
+				})
+			})
+		})
+	})
+})
+```