promises and fetch

Author: enuber

app/index.js

@@ -1,144 +1,29 @@
-//Generator
-// a generator can be entered and exited multiple times. We can return a value and then go right back into it
-//and keep going from the same location that we left.
-
-const colors = ['red', 'green', 'blue'];
-
-//for/of loop
-for (let color of colors) {
-    console.log(color);
-}
-
-//the *  makes this a generator
-function* shopping() {
-    //stuff on the sidewalk
-
-    // walking down the sidewalk
-
-    //go into the store with cash, //this is where we also reenter the generator
-    //with 'groceries' yield is a keyword that exits function and then when
-    //going back into the function we return to this place.
-    const stuffFromStore = yield 'cash';
-    //walking to laundrymat
-    const cleanClothes = yield 'laundry';
-    // walking back home
-    return [stuffFromStore, cleanClothes];
-}
-
-//stuff in the store
-//this doesn't actually go through the function
-const gen = shopping();
-//gives {'done': false} leaving our house, this is where we actually go into
-//the function.
-gen.next();
-//walked into the store at this point
-//walking through the store up and down the aisles
-//purchased our stuff
-// gives {'done': true} leaving the store with groceries
-gen.next('groceries');
-gen.next('clean clothes');
-
-
-function* colors() {
-    yield 'red';
-    yield 'green';
-    yield 'blue';
-}
-
-const myColors = [];
-for (let color of colors()) {
-    myColors.push(color);
-}
-
-myColors;
-
-
-const engineeringTeam = {
-    size: 3,
-    dept: 'Engineering',
-    lead: 'Jill',
-    manager: 'Alex',
-    engineer: 'Dave'
-}
-
-function* TeamIterator(team) {
-    yield team.lead;
-    yield team.manager;
-    yield team.engineer;
-}
-
-const names = [];
-for (let name of TeamIterator(engineeringTeam)) {
-    names.push(name);
-}
-
-names;
-
-//refractored
-const testingTeam = {
-    lead: 'Amanda',
-    tester: 'Bill',
-    //the Symbol.iterator gets used if it exists to use the generator it is
-    //pointing at to iterate over the object. the Symbol.iterator just teaches
-    //the for/of loop how to iterate over the object. Note the use of this as
-    //we are referring to the object that this generator is within.
-    [Symbol.iterator]: function* () {
-        yield this.lead;
-        yield this.tester;
-    }
-}
-
-const engineeringTeam = {
-    size: 3,
-    dept: 'Engineering',
-    lead: 'Jill',
-    manager: 'Alex',
-    engineer: 'Dave',
-    //could just be testingTeam by itself since it's key value is same
-    testingTeam: testingTeam,
-    [Symbol.iterator]: function* () {
-        yield this.lead;
-        yield this.manager;
-        yield this.engineer;
-        //this yield causes the for/of loop to iterate over the team.testingTeam
-        yield* this.testingTeam;
-    }
-}
-
-const names = [];
-for (let name of engineeringTeam) {
-    names.push(name);
-}
-names;
-
-
-//tree
-
-class Comment {
-    constructor(content, children) {
-        this.content = content;
-        this.children = children;
-    }
-    *[Symbol.iterator]() {
-        yield this.content;
-        for (let child of this.children) {
-            yield* child;
-        }
-    }
-}
-
-const children = [
-    new Comment('good comment', []),
-    new Comment('bad comment', []),
-    new Comment('meh',[])
-];
-
-const tree = new Comment('Great post!', children);
-
-const values = [];
-
-for (let value of tree) {
-    values.push(value);
-}
-
-values;
+//promises
+
+let promise = new Promise((resolve, reject) => {
+    setTimeout(() => {
+        resolve();
+    }, 3000);
+
+});
+
+promise
+    .then(() => {
+    console.log('finally finished');
+    })
+    .then(()=>{
+    console.log('I was also ran!')
+    })
+    .catch(() => {
+    console.log('uh oh...rejected');
+    });
+
+//fetch
+
+const url = 'https://jsonplaceholder.typicode.com/posts/';
+
+fetch(url)
+    .then(response => response.json())
+    .then(data => console.log(data))
+    //if fails, catch does not actually happen. unless the request flat out fails to happen
+    .catch(error => console.log('Bad', error));