diff --git a/docs/README.md b/docs/README.md index 223b44d..7518dbe 100644 --- a/docs/README.md +++ b/docs/README.md @@ -26,7 +26,7 @@ This workshop starts as a very high level introduction to the core principles of $ npm start ``` -After the project loads in your browser, click on `Step 0 - HTML/CSS/JS`. Then go to the `Day 1: Step 0` page for the lesson and exercise instructions. +After the project loads in your browser, click on `Step 1 - HTML/CSS/JS`. Then go to the `Day 1: Step 1` page for the lesson and exercise instructions. ### Additional Resources diff --git a/docs/step1-02/README.md b/docs/step1-02/demo/README.md similarity index 79% rename from docs/step1-02/README.md rename to docs/step1-02/demo/README.md index 2b29ba0..2aa4110 100644 --- a/docs/step1-02/README.md +++ b/docs/step1-02/demo/README.md @@ -80,16 +80,3 @@ Open up the browser inspector and target our 'all' button. You'll notice that th > **Specificity** states that regardless of cascade, the selector with the highest specificity wins To fix this problem we need to either reduce the specificity of our button styles, or increase the specificity of the selected style. In this situation we will add `.filter` in front of the `.selected` selector, because the selected style only applies to the filter anyway. - -## Exercise - -1. Add an unordered list with class `todos` to the main section -2. Add 4 list items with class `todo` inside of that list with the following content - `` -3. Add a span and a button to your footer -4. Span content should be `4 items left` and button should say `Clear Completed` and have a class of `submit` -5. Go into the CSS file and add `display: flex` to the footer. Also add `flex-grow:1` to the span inside of the footer - -> Hint: Look back at the CSS demo to see the various ways you can use selectors to target existing HTML - -> There are many strategies for creating and organizing class names in a large application. This lesson is focused on using CSS selectors, not the optimized way to scale your CSS. diff --git a/docs/step1-02/exercise/README.md b/docs/step1-02/exercise/README.md new file mode 100644 index 0000000..e09495f --- /dev/null +++ b/docs/step1-02/exercise/README.md @@ -0,0 +1,12 @@ +## Exercise + +1. Add an unordered list with class `todos` to the main section +2. Add 4 list items with class `todo` inside of that list with the following content + `` +3. Add a span and a button to your footer +4. Span content should be `4 items left` and button should say `Clear Completed` and have a class of `submit` +5. Go into the CSS file and add `display: flex` to the footer. Also add `flex-grow:1` to the span inside of the footer + +> Hint: Look back at the CSS demo to see the various ways you can use selectors to target existing HTML + +> There are many strategies for creating and organizing class names in a large application. This lesson is focused on using CSS selectors, not the optimized way to scale your CSS. diff --git a/docs/step1-03/README.md b/docs/step1-03/demo/README.md similarity index 73% rename from docs/step1-03/README.md rename to docs/step1-03/demo/README.md index fced277..a9a15cf 100644 --- a/docs/step1-03/README.md +++ b/docs/step1-03/demo/README.md @@ -39,23 +39,3 @@ document.querySelector('.addTodo .submit').onclick = addTodo; ``` Today we'll use #2, as this is the way it will work in React as well. - -## Exercise - -### Write updateRemaining function - -1. Get a reference to the span with the `remaining` class, and store it in a variable -2. Use [querySelectAll](https://developer.mozilla.org/en-US/docs/Web/API/Document/querySelectorAll) to get all of the todos. -3. Set the `innerText` of the remaining span to the length of those todos. -4. Add updateRemaining() to addTodo - -### Write a clearCompleted function - -1. Get a reference to all of the todos with [querySelectAll](https://developer.mozilla.org/en-US/docs/Web/API/Document/querySelectorAll) -2. Use a `for (let todo of todos)` loop to iterate over each todo -3. Inside the for loop write an `if` statement to test if the `input` inside of the todo has a checked value of true - > Hint: you can use querySelector on any HTML node to find child elements within -4. Call `todo.remove()` for any todo whos input check is true -5. After the loop is done, run `updateRemaining()` -6. Attach this function to the footer button -7. Test it out! diff --git a/docs/step1-03/exercise/README.md b/docs/step1-03/exercise/README.md new file mode 100644 index 0000000..b3736b4 --- /dev/null +++ b/docs/step1-03/exercise/README.md @@ -0,0 +1,19 @@ +## Exercise + +### Write updateRemaining function + +1. Get a reference to the span with the `remaining` class, and store it in a variable +2. Use [querySelectAll](https://developer.mozilla.org/en-US/docs/Web/API/Document/querySelectorAll) to get all of the todos. +3. Set the `innerText` of the remaining span to the length of those todos. +4. Add updateRemaining() to addTodo + +### Write a clearCompleted function + +1. Get a reference to all of the todos with [querySelectAll](https://developer.mozilla.org/en-US/docs/Web/API/Document/querySelectorAll) +2. Use a `for (let todo of todos)` loop to iterate over each todo +3. Inside the for loop write an `if` statement to test if the `input` inside of the todo has a checked value of true + > Hint: you can use querySelector on any HTML node to find child elements within +4. Call `todo.remove()` for any todo whos input check is true +5. After the loop is done, run `updateRemaining()` +6. Attach this function to the footer button +7. Test it out! diff --git a/docs/step1-04/README.md b/docs/step1-04/README.md deleted file mode 100644 index 3876cef..0000000 --- a/docs/step1-04/README.md +++ /dev/null @@ -1,211 +0,0 @@ -# Introduction To React - -In our last example we saw how we could take a static HTML page and turn it into an interactive page with some buttons and their `onclick` handlers. - -In this example we'll see how React turns that paradigm completely around. With React, the entire DOM is generated and maintained by JavaScript, directly inside the browser. This makes it easier to assemble your application out of reusable pieces, maintain state within a component, and pass data between them. - -## Demo - -In this demo we'll be creating a simple counter that will display a count and increment on click. - -### The App - -This is the starting point of our React application. It is a component just like the other ones we will be building, but this component will only ever be used once, to render the application. Here's how our app starts out. Let's walk through each line: - -```jsx -import React from 'react'; - -export class App extends React.Component { - render() { - return ( -
-

My App

-
- ); - } -} -``` - -- **import React from 'react';** - This is how we [import modules](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/import) in Javascript. This line creates a variable in this file called `React` that is equal to the default `export` of the `react` npm module. -- **export class App** - Just like react exports code, our App component is nothing more than an exported "App" class. This allows us to import the class into other files -- **extends React.Component** - A JavaScript class is similar to other programming languages (it's a collection of methods and properties). Classes can also be extended, so when we create a React component class, we always extend the base React.Component class. Note that this `Component` class is coming from the `React` variable imported up top. - > Note that `` is necessary for Typescript which we will touch on later -- **render()** - One of the methods defined by React.Component is the `render()` method. This is a function that defines the HTML the component is going to render. -- **return** - Remember that functions can return values in addition to side effects, and this component is no different. -- **Inside of the return?** It's HTML! Actually, it's JSX, but with very few exceptions you can treat it like HTML. A few key differences: - 1. Since 'class' is a reserved word in JavaScript, you will need to use className on your HTML tags `
` - 2. We can use custom HTML tags created by these render functions `
hi
` - 3. Controls can be self closing `
` - 4. You can use JavaScript inside of JSX! If you declare `const name = 'Micah';` inside the render function, you can use that variable inside of your JSX `
{name}
` or `
`. Works with functions, loops, conditionals as well. - -### index.jsx - -This is the file that places your App onto the page. - -```jsx -import React from 'react'; -import ReactDOM from 'react-dom'; -import { App } from './App'; -ReactDOM.render(, document.getElementById('app')); -``` - -- **import ReactDOM from "react-dom";** - We've seen React imported before, but now we're also grabbing ReactDom from a package called "react-dom". - > Note that this casing is intentional. NPM packages are kabab-case, exported items are usually camelCase or PascalCase. PascalCase is usually used for 'proper noun' exports. ProjectName, ComponentName etc. -- **import { App } from "./App";** - If we had exported our app like this: `export default class extends React.Component`, this line would look like the lines above - `import App from "./App";`. But React convention is to use named exports, which can easily be extracted like this `{ App }`. - > This notation is called [object destructuring](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment#Object_destructuring), and it's awesome! -- **ReactDOM.render...** This line calls the render function inside of ReactDOM and attaches our `` component to the element with `id=app`. Take a peak in the index.html file. Shouldn't be too hard to find it. - -### Counter Component - -In this example we'll start with an already scaffolded out control. The goal of our counter is to keep track of how many times the counter button is clicked. In the past JavaScript demo we might grab a reference to `document.querySelector('.counter')` and then manually increment the number we find there. While using the DOM as you data store works, it's REALLY hard to scale past the most basic demo. - -React solves this by allowing each control to specify its own data store, called 'state'. We can reference values in state when we render our UI, and we can also update state over the lifetime of our application. - -#### Adding State - -JavaScipt uses a `constructor` method to instantiate each copy of a class. So for class based controls, this is where we specify state. - -```js -constructor(props) { - super(props); - this.state = { - counter: 0 - }; - } -``` - -- The constructor takes in the component props (values passed into the control). -- the [super()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/super) function is called to gain access to some functionality in React.Component -- Now we can define any state variables we want to use in the control, and give them a default value. This counter value can now be accessed via `this.state.counter`. We can also update state by calling `this.setState({counter: 1})` - -#### Using [object destructuring](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment#Object_destructuring) for props and state - -Both props are state are JavaScript objects. They have a bunch of key value pairs in them which you can access via `this.props.foo` or `this.state.bar`. Sometimes they have **MANY** values inside of them which you need access to. You could do this: - -```js -let cat = this.props.cat; -let dog = this.props.dog; -let bird = this.props.bird; -let pig = this.props.pig; -let cow = this.props.cow; -``` - -> Note that we access props and state on `this`, which is how you reference all of the class properties and methods - -But this is verbose and repetative. Instead you can use destructuring to turn this into a one liner. - -```js -let { cat, dog, bird, pig, cow } = this.props; -``` - -So even though this isn't 100% necessary today, it does future proof our code if we add more props or state later. So let's add this inside of the render method, but above the return: - -```js -const { counter } = this.state; -const { text } = this.props; -``` - -#### Adding JSX - -```jsx -return ( -
- {text}: {counter} - -
-); -``` - -Each JSX return needs to be a single element, so start with a wrapping `
`. Inside of that we can add the `text` we get from `this.props`, then after a colon, the `counter` we pulled in from `this.state`. This will render as the string `My Text Prop: 0`. After that let's add a button we'll use later. For now, we're going to see how we can use this in our app. - -#### Updating the App to use Counters - -Before we can use our `Counter`, we need to import it into the App file - -```js -import { Counter } from './components/Counter'; -``` - -Now that we have access to `Counter`, we can add it to the App just as if it were an HTML element. - -```jsx -return ( -
-

My App

- - -
-); -``` - -> Note the capitalization of Counter. HTML might not be case sensative, but JSX is! A common practice is to use the capitalized versions of HTML elements to name their JSX counterpart. Button, Select, Label, Form etc. - -### Exploring Component Props - -Now that we've got two Counters on our page, we can see that the string passed into the `text` attribute got passed into our Counter, and rendered on the page. Being able to pass values into controls make them more flexible and reusable. Props can be strings, numbers, booleans, and even arrays and objects. - -```jsx - -``` - -> Note that all non string values are passed through as JavaScript by wrapping it in `{}` - -### Writing our Button Click - -Our next step is to wire up the button to increment the `counter` in our component state. This will very similar to what we did in step 3, but instead of placing the function in a script tag, we can create it as a class method, and keep it out of the global scope. - -> By convention we place methods below render, and private methods (those for internal use only) are prefixed with an underscore. - -```jsx -_onButtonCLick = () => { - this.setState({ counter: this.state.counter + 1 }); -}; -``` - -This function will update our component state, incrementing our counter value by 1. Note that setState only affects the values of keys we have listed. - -> Note that this isn't exactly a method, but a property that is equal to a [arrow function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions). This works just as well as `onButtonClick() { }`, but doesn't require extra binding up in the constructor. - -Now that we have a function to increment out count, all that we have left is to connect it to our button. - -```jsx - -``` - -> Note the syntax is a bit different than HTML. `onclick="funcName()"` vs `onClick={this.funcName}` - -> Also note that each Counter maintains its own state! You can modify the state insde of one without affect the others. - -## Bonus: Using a Button component - -Buttons are one of the most common components to write. They help abstract common styling, add icons or other decorations, and increase functionality (menu buttons etc). Using an existing Button component is as easy as importing it `import {Button} from './Button';` and replacing `` with ``. Lets take a quick look at button to see how it came together. - -```jsx -import React from 'react'; -import './Button.css'; - -export const Button = props => { - return ( - - ); -}; -``` - -- All controls need to import React (don't worry, only 1 copy ever gets into your app) -- Importing CSS files into the component means that the CSS is only loaded if the component is used -- React components can be created as a class **or** as a function. In this function, props are passed in as a function parameter. - > Until recently, you could only access state in class based components. But with the advent of [hooks](https://reactjs.org/docs/hooks-intro.html) you can create stateful function components. -- Since this is a function, we don't have any methods, including `render()`. Just return your JSX as you would in a class based component. -- `props.children` is anything passed between the opening and closing tags `` diff --git a/docs/step1-05/README.md b/docs/step1-05/demo/README.md similarity index 78% rename from docs/step1-05/README.md rename to docs/step1-05/demo/README.md index 1006f06..5bcbab1 100644 --- a/docs/step1-05/README.md +++ b/docs/step1-05/demo/README.md @@ -72,16 +72,3 @@ return ( ``` > Note that I've removed the title span as it was only needed to make targeting that text easier - -## Exercise - -### TodoFooter - -1. Update the TodoFooter component, copying over the `