njsx

No-JSX

A customizable and declarative interface for creating React and React Native components without JSX syntax.

If you love React but don't quite like the embeded HTML tags this library may be what you are looking for.

const myView () =>
  div('.App')(
    div('.App-header')(
      img('.App-logo')({src: logo, alt:'logo'}),
      h2('Welcome to NJSX')
    )
  )()

Installation

NJSX is available as the njsx package on npm. Just run the following line in your project root:

npm install njsx --save

Usage

NJSX provides a series of builder functions to cleanly instantiate React or React Native components. Just import the components you need from right module and you are ready to go.

// React project
import {div, p} from 'njsx/react'

// React Native project
import {View, Text} from 'njsx/react-native'

Building Components

Each imported NJSX builder is a function that once applied with no arguments will yield a React Component.

import {div} from 'njsx/react'

const someDiv = <div></div>
const anEqualDiv = div()
// These two lines yield the same!

If the builders are applied with one or more arguments, these will be used to configure the generated components. Each builder can be applied any number of times (up until you apply it with no arguments to construct the component).

import {p} from 'njsx/react'

p('some text')()
p('some', ' ', 'text')()
p('some ')('text')()
p(['some', ' '],['text'])()

//All these lines yield the same component
<p>some text</p>

Each argument is process by a set of configurable rules to decide what change it represents for the component. Here are some examples of argument applications you can use right out of the box:

• Hashes will become component's properties.

  img({src: somePath, onClick: someCallback})
  

  Applying a builder with a second hash will result in the new properties merging with the old, keeping the later in case of repetition.

  img({src: thisWillBeLost, onClick: thisWillRemain})({src: thisWillOverrideThePreviousPath})
  

• Strings, Numbers, Booleans, React Components and even other NJSX Builders will become childrens.

  div(
    div('the answer is ', 42)  // <- No need for building
  )()
  

  Notice that, since builders can be children too, most of the time there is no need to apply them with no args to create components.

• In react projects, Strings starting with a dot will be interpreted as a classes.

  div('.thisIsAClass .thisIsAnotherClass')(
    'Some content'
  )
  

• In react-native projects, StyleSheet entries can be interpreted as styles. Just import StyleSheet from njsx/react-native instead of react-native.

  import {StyleSheet, View, Text} from 'njsx/react-native'
  
  // Same StyleSheet interface
  StyleSheet.create({
    container: { /* ...your regular react-native styles... */ }
    description: { /* ...your regular react-native styles... */ }
  })
  
  View(styles.container)(
    Text(style.description)("These are styled!")
  )
  

• Null and Undefined arguments are ignored.

Any unsuported argument application will raise a TypeError.

If the running environment supports ES6's Proxy, component's property access can be used to further refine an existing component. By default, in react projects, this is set to make each property access yield a new component with the property name as a class:

//all these yield the same component
p.highlighted.small("hello!")
p['highlighted small']("hello!")
p("hello!").highlighted['.small']
<p className="highlighted small">hello!</p>

Advanced Customization

You don't like the way arguments are being handled? No problem! You can customize the rules NJSX uses for interpreting arguments to fine tune it to your needs. Add or remove supported argument applications, change the way they are processed or throw all away and start from scratch!

import njsx from 'njsx/njsx'   // This is NJSX core. Booth React and ReactNative use it to define their builders.
import Rules from 'njsx/rules' // This module exports some common rule examples.

Each rule is just an object with two methods:

• appliesTo(argument): Tells if the rule can handle an argument applied to a component builder.
• apply(argument, {props,children}): Takes the argument applied to a component builder and the curent state of the builder (denoted by an object containing a props hash and a children array) and returns the next builder state.

Rules.STRING_AS_CHILD = {
  // This rule only applies to arguments of type string.
  appliesTo(arg) { return typeof arg === 'string' },
  
  // Applying this rule adds the string to the children array (but it doesn't change the properties).
  apply(arg, {props, children}) { return {props, children: [...children, arg] }}
}

So you could easily create, for example, a rule that can handle anything that defines a toString() function and adds its result as a child.

const strigableAsChild = {
  appliesTo(arg) { return arg.toString && typeof(arg.toString) === 'function' },
  apply(arg, {props, children}) { return {props, children: [...children, arg.toString()] }}
}

njsx.rules.push(stringableAsChild) // From now on, all builders will support this rule.

Take into account that only one rule will be applied to each argument, and each rule will be tested for applicability in the same order as it appears in the njsx.rules array, so be carefull to leave the more generic rules at the bottom.

Finally, if you want to change how property access is handled by the builders, you can do so by setting the njsx.dynamicSelectorHandler property to a function that takes the accessed property name and the current builder state and returns the next state. For example, if you want the accesses to be treated as class names in a react-native project, you can do so by adding this line:

  njsx.dynamicSelectorHandler = Rules.STRING_AS_CLASS.apply

You can also set this property to a falsy value to disable the whole property access behavior for builders.

Contributions

Please report any bugs, requests or ideas on the issues section and we will try to see to it as soon as possible. Also, pull requests are always welcome! Just try to keep it small and clean.

License

This code is open source software licensed under the ISC License by The Uqbar Foundation. Feel free to use it accordingly.

Changelog

v2.1.5

• Support for React-Native styles as builder arguments.
• React-Native components will not be evaluated until used.