Understanding the Problem Space

jQuery and Reactive Framework Conflicts

Semantic UI relies heavily on jQuery to initialize behaviors and manage DOM events. In reactive frameworks, DOM elements are frequently destroyed and recreated, but Semantic UI expects static DOM. This mismatch leads to uninitialized dropdowns, modals that don't show, and components that break silently.

Use Case Scenario

A common enterprise use case involves rendering Semantic UI modals or dropdowns conditionally. The initial DOM is hydrated before jQuery can initialize components, leading to broken behavior unless manually re-triggered.

Diagnostics and Root Cause Analysis

Symptoms

  • Dropdowns not responding to clicks
  • Modals not showing or failing to center
  • Tooltips showing in wrong positions
  • Styles not applying when using custom themes

Diagnostic Steps

  • Inspect if $('.ui.dropdown').dropdown() or similar initializations are being called after the component mounts.
  • Use browser dev tools to check if Semantic UI classes like active, visible, transitioning are present.
  • Monitor console logs for errors like Cannot read property 'modal' of undefined or $.fn.dropdown is not a function.
  • Verify jQuery is loaded before Semantic UI JS in the build pipeline.

Fixing Initialization Issues in Reactive Frameworks

React Workaround Example

Use useEffect to reinitialize components post-render:

import React, { useEffect } from 'react';
import $ from 'jquery';
import 'semantic-ui-css/semantic.min.js';

const DropdownComponent = () => {
  useEffect(() => {
    $('.dropdown').dropdown();
  }, []);

  return (
    <div className="ui dropdown">
      <div className="text">Select Option</div>
      <i className="dropdown icon"></i>
      <div className="menu">
        <div className="item">Option 1</div>
        <div className="item">Option 2</div>
      </div>
    </div>
  );
};

Angular Workaround Using ngAfterViewInit

In Angular, defer Semantic UI initialization to ngAfterViewInit:

import { AfterViewInit, Component } from '@angular/core';
declare var $: any;

@Component({
  selector: 'app-dropdown',
  templateUrl: './dropdown.component.html'
})
export class DropdownComponent implements AfterViewInit {
  ngAfterViewInit() {
    $('.dropdown').dropdown();
  }
}

Addressing Theming and Build Issues

Custom Theme Fails to Apply

Semantic UI themes require a full Gulp-based build or Fomantic-UI tooling. Using CDN styles while attempting overrides via CSS often fails due to selector priority and missing variables.

Proper Theming Workflow

  • Clone Semantic UI or Fomantic UI repo
  • Run npx gulp build after editing theme.config
  • Ensure the built CSS is loaded before any component rendering
  • For React, import built CSS inside index.js or App.js

Best Practices for Semantic UI in Enterprise Projects

  • Switch to Fomantic UI for more active maintenance
  • Use component wrappers (e.g., semantic-ui-react) to abstract jQuery usage
  • Initialize components only after DOM is ready
  • Validate jQuery plugins are loaded in expected order
  • Use static HTML previews for QA instead of dynamic previews when possible

Conclusion

Semantic UI provides a great developer experience for rapid UI development, but its jQuery-centric model introduces complexity in reactive applications. Initialization issues, theming inconsistencies, and build mismatches can silently degrade UX in production. By adopting reactive-aware initialization, structured theming workflows, and best practices like switching to Fomantic UI or using wrapper libraries, teams can confidently use Semantic UI at enterprise scale.

FAQs

1. Why do Semantic UI dropdowns not work in React?

They require manual jQuery initialization after the DOM is rendered. Use useEffect to trigger $('.dropdown').dropdown() on mount.

2. Is Semantic UI still maintained?

Semantic UI is largely inactive, but Fomantic UI is a community-maintained fork with additional features and better maintenance.

3. Can I override Semantic UI themes using only CSS?

It's discouraged. Use the Gulp theming build pipeline to modify variables and regenerate CSS for consistent overrides.

4. Why do my modals not center correctly?

They often require calling $('.modal').modal('refresh') after content load or visibility change, especially inside dynamic views.

5. Should I use semantic-ui-react instead of Semantic UI directly?

Yes, if using React, the wrapper provides React-friendly components that abstract away jQuery, reducing potential bugs.