Some React Components

This is a collection of some declarative components for React eg: Visible, Switch, ForEach etc...

Why

Because I don't like this

render(){
  return <span>
      {this.state.user && this.state.user.loggedIn && <h3>{this.state.user.name}</h3>}
  </span>
}

I like writing this way

render(){
  return <Visible when={this.state.user && this.state.user.loggedIn}>
      <h3>{this.state.user.name}</h3>
  </Visible>
}

Also it gets more complicated when it has more states/branches with ternary operators

<span>
    {this.state.user && this.state.user.loggedIn ? (
      <h3>{this.state.user.name}</h3>
    ):(
      <h3><a href="/login">Please login</a></h3>
    )}
</span>

Instead I prefer using something like this.

    <Switch>
      <Case when={this.state.user && this.state.user.loggedIn}>
        <h3>{this.state.user.name}</h3>
      </Case>
      <Else >
        <h3><a href="/login">Please login</a></h3>
      </Else>
    </Switch>

Or simply - if you only need boolean conditionals

    <Visible when={this.state.user && this.state.user.loggedIn}>
        <h3>{this.state.user.name}</h3>
      <Other />
        <h3><a href="/login">Please login</a></h3>
    </Visible>

Of course your milage may vary, but I think the second form is more easy when you just scan the code.

Also foreach/map there is a ForEach component that takes an iterable and renders the components in a loop. More or less the same thing as array.map but easier to read.

  const UserLabel = (props)=>{
    return <div>{props.id} | {props.name}</div>
  }
  // ...
  let somedata = [{id:1, name: 'a'}, {id:2, name: 'b'}]
  // ...

  <ForEach data={somedata} expandProps>
    <UserLabel />
  </ForEach>

Installation & Usage

yarn add somereactcomponents

or

npm i somereactcomponents --save

then you can use it as usual

import {Visible, Switch, Case, Else, Other, ForEach, stateUpdater} from "somereactcomponents";

FAQ/Notes

Do I really need this ?

Short answer, no probably not, but its easier to read/write - for me - and looks more declarative. Although it adds some overhead ofcourse, but its negligible, foreach wraps a simple map function, and Visible/Switch wraps some if clause, so the impact shouldn't be noticable.

Why not put this as a preprocessor - eg. webpack ?

It makes things much complicated than it should.