mayre

Maybe render a React component, maybe not 😮

// Get it!
yarn add mayre
npm install --save mayre

While working with React you'll find yourself making conditionals components quite a lot of times. And they're always the same: a component which upon a set of conditions may render or just return null (or short-circuit it).

Here comes Mayre (Maybe render)! A very simple and super light (2kb) component to tackle this issue from the jsx side.

Compatible with React, React-Native and ReactVR.

Usage

Maybe

There are three props you can use: of, when and with.

<Mayre
  of={MyComponent}
  when={props.something > 10}
  with={{ some: 'thing' }}
/>

Note that of can be a component instance or declaration. And when can be boolean or a function.

<Mayre
  of={<p>Something</p>}
  when={() => checkWhatever()}
/>

Either

But not only this! Conditional rendering isn't only about mount this component or not. We can also use Mayre to render either this element or the other.

<Mayre
  of={<p>Either this</p>}
  or={<p>Or this one</p>}
  when={whateverCondition}
/>

If a with prop is provided it'll be applied to both of them. If you want to specify special props for each of them use orWith.

<Mayre
  of={<p>Either this</p>}
  or={<p>Or this one</p>}
  when={whateverCondition}
  with={{ appliedTo: 'of' }}
  orWith={{ appliedTo: 'this will used by or element' }}
/>

Auto props picking

Most of the times the component rendered by Mayre is a subset of a bigger one. Hence, it's using a selection of the parent props. That's why Mayre has a special syntax to pick the props you need to while passing them down.

<Mayre
  of={MyComponent}
  when={props.something > 10}
  with={[props, 'thisProps', 'andThisOther']}
/>

Same can be applied for orWith attribute.

Props

Name	Required	Default	Type	Comment
of	Yes	-	func, element	The React component to be rendered
or	No	null	func, element	The React component rendered instead of of
when	No	false	bool, func	The render condition
with	No	{}	object, array	Props to be passed to of/or component
orWith	No	{}	object, array	Props to be passed to or component

Benefit

Stop doing this:

// no more dumb render methods pollution
const renderSomething = (canRender, propsFromParent) => {
  if (!canRender) return null

  return <Something {...propsFromParent} />
}

const Parent = (props) => (
  <div>
    {renderSomething(props.a === props.b, props)}
  </div>
)