|
| 1 | +## ⚑ Web APIs: |
| 2 | +Web APIs are a set of built-in JavaScript objects that can provide an access to the browser's environment and allow web applications to interact with hardware, network resources, and other parts of the system through the browser. |
| 3 | + |
| 4 | +### ☴ Overview: |
| 5 | +1. [Fetch API](#-fetch-api) |
| 6 | +2. [WebSockets](#-websockets) |
| 7 | +3. [Local Storage](#-local-storage) |
| 8 | +4. [Session Storage](#-session-storage) |
| 9 | +5. [Geolocation API](#-geolocation-api) |
| 10 | +6. [Canvas API](#-canvas-api) |
| 11 | +7. [Web Audio API](#-web-audio-api) |
| 12 | +8. [Clipboard API](#-clipboard-api) |
| 13 | +9. [Web camera API](#-web-camera-api) |
| 14 | +10. [Microphone API](#-microphone-api) |
| 15 | +11. [Handling Cookies](#-handling-cookies) |
| 16 | +12. [Other APIs](#-other-apis) |
| 17 | + |
| 18 | +### ✦ Fetch API: |
| 19 | +A modern API for making network requests for the data required in JavaScript. |
| 20 | + |
| 21 | +*Syntax:* |
| 22 | +```javascript |
| 23 | +fetch(url, options) |
| 24 | + .then(response => response.json()) |
| 25 | + .then(data => { |
| 26 | + // Handle the data |
| 27 | + }) |
| 28 | + .catch(error => { |
| 29 | + // Handle errors |
| 30 | + }); |
| 31 | +``` |
| 32 | + |
| 33 | +```javascript |
| 34 | +fetch('https://api.example.com/data') |
| 35 | + .then(response => response.json()) |
| 36 | + .then(data => { |
| 37 | + console.log(data); |
| 38 | + }); |
| 39 | +``` |
| 40 | + |
| 41 | +### ✦ WebSockets: |
| 42 | +A protocol for establishing persistent, full-duplex communication channels between a client and a server. |
| 43 | + |
| 44 | +*Syntax:* |
| 45 | +```javascript |
| 46 | +const socket = new WebSocket('ws://example.com:8080'); |
| 47 | +``` |
| 48 | + |
| 49 | +```javascript |
| 50 | +const socket = new WebSocket('ws://example.com:8080'); |
| 51 | + |
| 52 | +socket.onopen = () => { |
| 53 | + console.log('WebSocket connection opened'); |
| 54 | +}; |
| 55 | + |
| 56 | +socket.onmessage = (event) => { |
| 57 | + console.log('Received message:', event.data); |
| 58 | +}; |
| 59 | + |
| 60 | +socket.onclose = () => { |
| 61 | + console.log('WebSocket connection closed'); |
| 62 | +}; |
| 63 | +``` |
| 64 | + |
| 65 | +### ✦ Local Storage: |
| 66 | +It allows to store data locally in the browser for a specific domain. |
| 67 | + |
| 68 | +```javascript |
| 69 | +/* Setting local storage value for specific key */ |
| 70 | +localStorage.setItem('key', 'value'); |
| 71 | +/* Reading local storage for the key */ |
| 72 | +let value = localStorage.getItem('key'); |
| 73 | +/* Removing local storage value on the key */ |
| 74 | +localStorage.removeItem('key'); |
| 75 | +/* Clearing local storage on the current site */ |
| 76 | +localStorage.clear(); |
| 77 | +``` |
| 78 | + |
| 79 | +### ✦ Session Storage: |
| 80 | +It allows to store data locally in the browser for a single session. |
| 81 | + |
| 82 | +```javascript |
| 83 | +/* Setting session storage */ |
| 84 | +sessionStorage.setItem('cart', JSON.stringify(cart)); |
| 85 | +/* Reading session storage */ |
| 86 | +let cart = JSON.parse(sessionStorage.getItem('cart')); |
| 87 | +``` |
| 88 | + |
| 89 | +### ✦ Geolocation API: |
| 90 | +It provides access to the user's geographical location. |
| 91 | + |
| 92 | +```javascript |
| 93 | +navigator.geolocation.getCurrentPosition(successCallback, errorCallback); |
| 94 | +``` |
| 95 | + |
| 96 | +```javascript |
| 97 | +navigator.geolocation.getCurrentPosition( |
| 98 | + (position) => { |
| 99 | + console.log(position.coords.latitude, position.coords.longitude); |
| 100 | + }, |
| 101 | + (error) => { |
| 102 | + console.error('Error:', error); |
| 103 | + } |
| 104 | +); |
| 105 | +``` |
| 106 | + |
| 107 | +### ✦ Canvas API: |
| 108 | +It allows to create 2d graphics on an HTML canvas element. |
| 109 | + |
| 110 | +```javascript |
| 111 | +let canvas = document.getElementById('myCanvas'); |
| 112 | +let context = canvas.getContext('2d'); |
| 113 | +context.fillStyle = 'red'; |
| 114 | +context.fillRect(10, 10, 100, 100); |
| 115 | +``` |
| 116 | + |
| 117 | +See More on this [Canvas Reference](https://github.com/ag-sanjjeev/HTML-Notes/blob/master/tags/link-tag.md) |
| 118 | + |
| 119 | +### ✦ Web Audio API: |
| 120 | +It provides an interface for creating, manipulating, and processing audio data. |
| 121 | + |
| 122 | +*Syntax:* |
| 123 | +```javascript |
| 124 | +let audioContext = new AudioContext(); |
| 125 | +``` |
| 126 | + |
| 127 | +```javascript |
| 128 | +audioContext.createOscillator().start(); |
| 129 | +``` |
| 130 | + |
| 131 | +### ✦ Clipboard API: |
| 132 | +It provides access to the user's clipboard. |
| 133 | + |
| 134 | +```javascript |
| 135 | +navigator.clipboard.writeText('Hello, world!'); |
| 136 | +navigator.clipboard.readText().then(text => console.log(text)); |
| 137 | +``` |
| 138 | + |
| 139 | +### ✦ Web camera API: |
| 140 | +It provides access to the user's webcam. |
| 141 | + |
| 142 | +```javascript |
| 143 | +navigator.mediaDevices.getUserMedia({ video: true }) |
| 144 | + .then(stream => { |
| 145 | + let video = document.getElementById('myVideo'); |
| 146 | + video.srcObject = stream; |
| 147 | + }) |
| 148 | + .catch(error => { |
| 149 | + console.error('Error:', error); |
| 150 | + }); |
| 151 | +``` |
| 152 | + |
| 153 | +### ✦ Microphone API: |
| 154 | +It provides access to the user's microphone. |
| 155 | + |
| 156 | +```javascript |
| 157 | +navigator.mediaDevices.getUserMedia({ audio: true }) |
| 158 | + .then(stream => { |
| 159 | + let audioContext = new AudioContext(); |
| 160 | + let source = audioContext.createMediaStreamSource(stream); |
| 161 | + // ... (process audio data) |
| 162 | + }) |
| 163 | + .catch(error => { |
| 164 | + console.error('Error:', error); |
| 165 | + }); |
| 166 | +``` |
| 167 | + |
| 168 | +### ✦ Handling Cookies: |
| 169 | +Cookies are small pieces of data stored on the user's computer by a web server as same as local storage. |
| 170 | + |
| 171 | +```javascript |
| 172 | +/* Setting Cookies */ |
| 173 | +document.cookie = 'name=Vel Murugan; expires=Thu, 31 Dec 2024 12:00:00 GMT'; |
| 174 | +/* Reading Cookies */ |
| 175 | +let cookies = document.cookie.split(';'); |
| 176 | +``` |
| 177 | + |
| 178 | +### ✦ Other APIs: |
| 179 | +- *Battery Status API:* Provides information about the device's battery status. |
| 180 | +- *Vibration API:* Allows the device to vibrate. |
| 181 | +- *Device Orientation API:* Provides information about the device's orientation. |
| 182 | +- *Device Motion API:* Provides information about the device's acceleration and rotation. |
| 183 | +- *Pointer Lock API:* Allows the user to lock the pointer to an element |
| 184 | + |
| 185 | +--- |
| 186 | +[⇪ To Top](#-web-apis) |
| 187 | + |
| 188 | +[❮ Previous Topic](./json.md) |
| 189 | + |
| 190 | +[⌂ Goto Home Page](../README.md) |
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