Awesome
obj-str
A tiny (96B) library for serializing Object values to Strings.
This module's intended use is for converting an Object with CSS class names (as keys) to a space-delimited className
string. Other modules have similar goals (like classnames
), but obj-str
only does one thing. This is why it's only 100 bytes gzipped!
PS: I made this because Preact 8.0 removed this built-in behavior and I wanted a quick, drop-in replacement.
Install
$ npm install --save obj-str
Usage
import objstr from 'obj-str';
objstr({ foo:true, bar:false, baz:isTrue() });
//=> 'foo baz'
React
With React (or any of the React-like libraries!), you can take advantage of any props
or state
values in order to express conditional classes as an object.
import React from 'react';
import objstr from 'obj-str';
const TodoItem = ({ text, isDone, disabled }) => (
<li className={ objstr({ item:true, completed:isDone, disabled }) }>
<input type="checkbox" disabled={ disabled } checked={ isDone } />
<label>{ text }</label>
</li>
);
Preact
For simple use, the React example will work for Preact too. However, you may also define a custom vNode "polyfill" to automatically handle Objects when used inside className
.
Note: For users of Preact 7.1 and below, you do not need this module! Your version includes this behavior out of the box!
import objstr from 'obj-str';
import { options } from 'preact';
const old = options.vnode;
options.vnode = vnode => {
const props = vnode.attributes;
if (props != null) {
const k = 'class' in props ? 'class' : 'className';
if (props[k] && typeof props[k]=='object') {
props[k] = objstr(props[k]);
}
}
old && old(vnode);
}
API
objstr(input)
input
Type: Object
A hashmap of keys & their truthy/falsey values. Booleans are preferred when speed is critically important.
Related
-
babel-plugin-optimize-obj-str - Babel plugin to transform
obj-str
calls into optimized expressions. -
clsx - Drop-in replacement for
obj-str
andclassnames
– handles all (and multiple) input types.
License
MIT © Luke Edwards