This guide provides a step-by-step approach to building your own JavaScript framework, a valuable exercise for deepening your understanding of popular libraries like React, Vue, and Angular.
Core Framework Components:
Most frameworks manage: DOM manipulation, state management, component-based architecture, and event handling. Building a basic framework offers practical experience with these core concepts.
Project Setup:
Begin by structuring your project:
<code>my-js-framework/ │── index.html │── framework.js │── app.js</code>
-
index.html: The main HTML file. -
framework.js: Your custom framework code. -
app.js: A test file to validate framework functionality.
Implementing Reactivity:
A crucial aspect of modern frameworks is reactivity. Let's create a simple state management system:
class Reactive {
constructor(value) {
this._value = value;
this.subscribers = new Set();
}
get value() {
return this._value;
}
set value(newValue) {
this._value = newValue;
this.subscribers.forEach(fn => fn());
}
subscribe(fn) {
this.subscribers.add(fn);
}
}
This enables components to update automatically when the state changes.
Virtual DOM and Rendering:
Instead of direct DOM manipulation, we'll implement a basic virtual DOM:
function createElement(tag, props, ...children) {
return { tag, props, children };
}
function renderElement(node) {
if (typeof node === "string") return document.createTextNode(node);
const el = document.createElement(node.tag);
if (node.props) {
Object.entries(node.props).forEach(([key, value]) => el.setAttribute(key, value));
}
node.children.map(renderElement).forEach(child => el.appendChild(child));
return el;
}
function mount(vnode, container) {
container.appendChild(renderElement(vnode));
}
This allows rendering like this:
const app = createElement("h1", {}, "Hello, World!");
mount(app, document.getElementById("root"));
This will render <h1>Hello, World!</h1> to the page.
Component System:
For modularity, let's add basic component support:
class Component {
constructor(props) {
this.props = props;
}
render() {
return createElement("div", {}, "Default Component");
}
}
This Component class can be extended to build custom components.
Performance Enhancements:
For efficiency, frameworks utilize diffing algorithms to update only modified DOM parts. While a complete diffing system is complex, you can start by comparing old and new virtual DOM trees and selectively updating changed elements.
Framework Application in PDF Tools:
Integrating a JavaScript framework into web-based PDF tools streamlines UI updates and improves performance. For instance, in a PDF editor, reusable components can be created for file uploads, text annotations, and dynamic PDF rendering.
Conclusion:
You've now created a foundational JavaScript framework with reactive state, a virtual DOM, and component support. While simplified, this provides valuable insight into how modern frameworks function. Further enhancements could include routing, lifecycle hooks, and more sophisticated DOM diffing.
The above is the detailed content of Building a Custom JavaScript Framework from Scratch. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
How to make an HTTP request in Node.js?
Jul 13, 2025 am 02:18 AM
There are three common ways to initiate HTTP requests in Node.js: use built-in modules, axios, and node-fetch. 1. Use the built-in http/https module without dependencies, which is suitable for basic scenarios, but requires manual processing of data stitching and error monitoring, such as using https.get() to obtain data or send POST requests through .write(); 2.axios is a third-party library based on Promise. It has concise syntax and powerful functions, supports async/await, automatic JSON conversion, interceptor, etc. It is recommended to simplify asynchronous request operations; 3.node-fetch provides a style similar to browser fetch, based on Promise and simple syntax
JavaScript Data Types: Primitive vs Reference
Jul 13, 2025 am 02:43 AM
JavaScript data types are divided into primitive types and reference types. Primitive types include string, number, boolean, null, undefined, and symbol. The values are immutable and copies are copied when assigning values, so they do not affect each other; reference types such as objects, arrays and functions store memory addresses, and variables pointing to the same object will affect each other. Typeof and instanceof can be used to determine types, but pay attention to the historical issues of typeofnull. Understanding these two types of differences can help write more stable and reliable code.
React vs Angular vs Vue: which js framework is best?
Jul 05, 2025 am 02:24 AM
Which JavaScript framework is the best choice? The answer is to choose the most suitable one according to your needs. 1.React is flexible and free, suitable for medium and large projects that require high customization and team architecture capabilities; 2. Angular provides complete solutions, suitable for enterprise-level applications and long-term maintenance; 3. Vue is easy to use, suitable for small and medium-sized projects or rapid development. In addition, whether there is an existing technology stack, team size, project life cycle and whether SSR is needed are also important factors in choosing a framework. In short, there is no absolutely the best framework, the best choice is the one that suits your needs.
JavaScript time object, someone builds an eactexe, faster website on Google Chrome, etc.
Jul 08, 2025 pm 02:27 PM
Hello, JavaScript developers! Welcome to this week's JavaScript news! This week we will focus on: Oracle's trademark dispute with Deno, new JavaScript time objects are supported by browsers, Google Chrome updates, and some powerful developer tools. Let's get started! Oracle's trademark dispute with Deno Oracle's attempt to register a "JavaScript" trademark has caused controversy. Ryan Dahl, the creator of Node.js and Deno, has filed a petition to cancel the trademark, and he believes that JavaScript is an open standard and should not be used by Oracle
Handling Promises: Chaining, Error Handling, and Promise Combinators in JavaScript
Jul 08, 2025 am 02:40 AM
Promise is the core mechanism for handling asynchronous operations in JavaScript. Understanding chain calls, error handling and combiners is the key to mastering their applications. 1. The chain call returns a new Promise through .then() to realize asynchronous process concatenation. Each .then() receives the previous result and can return a value or a Promise; 2. Error handling should use .catch() to catch exceptions to avoid silent failures, and can return the default value in catch to continue the process; 3. Combinators such as Promise.all() (successfully successful only after all success), Promise.race() (the first completion is returned) and Promise.allSettled() (waiting for all completions)
What is the cache API and how is it used with Service Workers?
Jul 08, 2025 am 02:43 AM
CacheAPI is a tool provided by the browser to cache network requests, which is often used in conjunction with ServiceWorker to improve website performance and offline experience. 1. It allows developers to manually store resources such as scripts, style sheets, pictures, etc.; 2. It can match cache responses according to requests; 3. It supports deleting specific caches or clearing the entire cache; 4. It can implement cache priority or network priority strategies through ServiceWorker listening to fetch events; 5. It is often used for offline support, speed up repeated access speed, preloading key resources and background update content; 6. When using it, you need to pay attention to cache version control, storage restrictions and the difference from HTTP caching mechanism.
Leveraging Array.prototype Methods for Data Manipulation in JavaScript
Jul 06, 2025 am 02:36 AM
JavaScript array built-in methods such as .map(), .filter() and .reduce() can simplify data processing; 1) .map() is used to convert elements one to one to generate new arrays; 2) .filter() is used to filter elements by condition; 3) .reduce() is used to aggregate data as a single value; misuse should be avoided when used, resulting in side effects or performance problems.
JS roundup: a deep dive into the JavaScript event loop
Jul 08, 2025 am 02:24 AM
JavaScript's event loop manages asynchronous operations by coordinating call stacks, WebAPIs, and task queues. 1. The call stack executes synchronous code, and when encountering asynchronous tasks, it is handed over to WebAPI for processing; 2. After the WebAPI completes the task in the background, it puts the callback into the corresponding queue (macro task or micro task); 3. The event loop checks whether the call stack is empty. If it is empty, the callback is taken out from the queue and pushed into the call stack for execution; 4. Micro tasks (such as Promise.then) take precedence over macro tasks (such as setTimeout); 5. Understanding the event loop helps to avoid blocking the main thread and optimize the code execution order.
