Conditionally applying class attributes in React

The Ternary Operator in JSX

To preserve readability in JSX, it's highly beneficial to encapsulate a ternary operator within parentheses. It gives fellow developers a clear sight of your render control:

<div className={condition ? 'class-if-true' : 'class-if-false'}>
  Content
</div>


This approach is like putting up a signpost, say "🚸 Code Crosswalk", for others to easily navigate through your conditional rendering.

Cleaner JSX with Logical AND

For situations where you simply need to append a class based on a truthy condition, the logical && operator does wonders:

<div className={`base-class ${condition && 'conditional-class'}`}>
  Content
</div>


Only when condition is truthy will 'conditional-class' be applied. It's like the operator saying, "What's my purpose?" and you reply, "You pass butter." 🍞🧈 Yup, it’s that simple.

Handling Multiple Condition-derived Classes

When dealing with multiple class names based on different conditions, the trick is to concatenate with spaces:

<div className={`base-class ${condition ? 'conditional-class-one' : ''} ${anotherCondition ? 'conditional-class-two' : ''}`}>
  Content
</div>


Remember, putting spaces between class names is like social distancing. It avoids unwanted mixing (read: clashing of styles!)

For Complex Logic: Classname Utilities

For complex scenarios, the clsx library simplifies syntax and boosts performance:

import clsx from 'clsx';

// ...

<div className={clsx('base-class', {
  'conditional-class-one': condition1,
  'conditional-class-two': condition2,
  // You can add more conditions. It's like a buffet, but easier on your waistline.
})}>
  Content
</div>


Alignment and Spacing Class

Sometimes you might want to conditionally apply aligning classes like pull-right:

<div className={`base-class ${condition ? 'pull-right' : ''}`}>
  Content
</div>


Our pull-right class is like the last kid picked in a soccer game. Except instead of kicking a ball, it's aligning your components.

Key Checks

• Ensure condition accurately returns boolean values.
• Avoid the "Schrodinger's cat" scenario of ambiguous classes like 'show' and 'hidden'.
• Weigh in on whether a default class for visibility is needed or conditional rendering suffices.

Save Classnames for Frequent Use

In cases where classname logic is reused, it’s good to precalculate the classname:

const computedClassName = `base-class ${condition ? 'conditional-class' : ''}`;

// ...

<div className={computedClassName}>
  Content
</div>


It's like preordering your favorite coffee; by the time you need it, it's hot and ready.

Direct Props to Classnames

If a prop directly corresponds to a class name, you can leverage this streamlined syntax:

<div className={`base-class ${this.props.isActive && 'active'}`}>
  Content
</div>


This method assumes isActive toggles the 'active' class. It’s like referring to Batman when you see the Bat-Signal. 🦇💡

ES6 Compatibility

Remember, template strings need to be configured for browser compatibility with a transpiler like Babel.