Lecture 08

abhishek97 · abhishek97 · commit 35362388a591 · 2019-06-28T11:28:25.000+05:30
diff --git a/Lecture08/async/counter.js b/Lecture08/async/counter.js
@@ -0,0 +1,5 @@
+const start = Date.now()
+
+setInterval(() => {
+    const shown = Date.now() - start
+}, 1000)
diff --git a/Lecture08/async/file.js b/Lecture08/async/file.js
@@ -0,0 +1,32 @@
+function download (url, callback) {
+    let file = "Some data here"
+    setTimeout(() => {
+        callback(null, file)
+    }, 3000)
+}
+
+function resize (file, callback) {
+    let resizedFile = "Compressed Stuff Here"
+    setTimeout(() => {
+        callback(null, resizedFile)
+    }, 5000)
+}
+
+function upload (file, callback) {
+    let url = "cb.lk/file.jpg"
+    setTimeout(() => {
+        callback(null, url)
+    }, 10000)
+}
+
+
+download('cb.lk/secret' , (err, file) => {
+    if (err) {
+        // handleError
+    }
+    resize(file, resizedFile => {
+        upload(resizedFile, url => {
+            console.log(url)
+        })
+    })
+})
diff --git a/Lecture08/async/hof.js b/Lecture08/async/hof.js
@@ -0,0 +1,23 @@
+// const generatePromise = (val, n) => 
+//     new Promise((resolve) => setTimeout(() => resolve(val), n))
+
+// const generatePromise = function (val, n) {
+//     const fn = function (resolve) {
+//         setTimeout(function () {
+//             resolve(val)
+//         }, n)
+//     } 
+//     return new Promise(fn)
+// }
+
+
+// generatePromise(1, 1000).then(console.log)
+// generatePromise(2, 2000).then(console.log)
+// generatePromise(3)(3000).then(console.log)
+// generatePromise(4, 4000).then(console.log)
+
+const generatePromiseHOF = val => n => 
+    new Promise((resolve) => setTimeout(() => resolve(val), n))
+
+const resolve3After = generatePromiseHOF(3)
+
diff --git a/Lecture08/async/index.js b/Lecture08/async/index.js
@@ -0,0 +1,14 @@
+// console.log(1)
+// console.log(2)
+
+
+
+setTimeout(() => {
+    console.log("after 1 sec")
+}, 1000)
+
+for (let i=0;i < 1e5; i++) {
+    console.log()
+}
+
+console.log("Done")
diff --git a/Lecture08/async/multiple.js b/Lecture08/async/multiple.js
@@ -0,0 +1,17 @@
+// setTimeout(() => {
+//     console.log(1)
+// }, 0)
+
+// setTimeout(() => {
+//     console.log(2)
+// }, 0)
+
+const id = setInterval(() => {
+    console.log("every 1 sec")
+}, 1000)
+
+setTimeout(() => {
+    clearInterval(id)
+}, 5100)
+
+console.log(3)
diff --git a/Lecture08/async/promise.js b/Lecture08/async/promise.js
@@ -0,0 +1,46 @@
+function download (url) {
+    const promise = new Promise((resolve, reject) => {
+        setTimeout(() => {
+            reject("New Error")
+        }, 1000)
+    })
+    return promise
+}
+
+function resize (file) {
+    const promise = new Promise((resolve) => {
+        setTimeout(() => {
+            resolve("Resized File")
+        }, 2000)
+    })
+    return promise
+}
+
+function upload (file) {
+    const promise = new Promise((resolve) => {
+        setTimeout(() => {
+            resolve("cb.lk/secret.jpg")
+        }, 5000)
+    })
+    return promise
+}
+
+
+const downloadedFile = download('cb.lk/file.jpg')
+const promise = downloadedFile.then(file => {
+    return resize(file)
+}).catch(err => {
+
+})
+.then(resizedFile => {
+    return upload(resizedFile)
+}).then(url => {
+    console.log(url)
+}).catch(err => {
+    console.log(err)
+}).then(() => {
+    console.log("Always")
+    throw new Error("Some err")
+}).catch(err => {
+    console.log("error Again")
+})
diff --git a/Lecture08/index.html b/Lecture08/index.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <meta http-equiv="X-UA-Compatible" content="ie=edge">
+    <title>Document</title>
+</head>
+<body>
+    <button id="btn">Click Me</button>
+    <script src="index.js"></script>
+</body>
+</html>
diff --git a/Lecture08/index.js b/Lecture08/index.js
@@ -0,0 +1,7 @@
+const button = document.getElementById('btn')
+
+button.onclick = function () {
+    console.log("clicked")
+}
+
+console.log("JS Finished")
