Live demo
Related Stackoverflow q&a
Rationale
react
/react-dom
comes comes with 2 basic assumptions/ideas:
- every UI is hierarchical naturally. This why we have the idea of "
components
wrap each other" react-dom
mounts (physically) child component to its parent DOM node by default
The problem is that sometimes the second property isn't what you want in your case. Sometimes you want to mount your component into different physical DOM node and hold logical connection between parent and child at the same time.
Canonical example is Tooltip-like component: at some point of development process you could find that you need to add some description for your UI element
: it'll render in fixed layer and should know its coordinates (which are that UI element
coord or mouse coords) and at the same time it needs information whether it needs to be shown right now or not, its content and some context from parent components. This example shows that sometimes logical hierarchy isn't match with the physical DOM hierarchy.
import React, { Component } from 'react';
import { Layer, LayerContext } from 'react-layer-stack';
class Demo extends Component {
render() {
return (
<div>
<LayerContext id="lightbox">{({ showMe, hideMe }) => (
<button onMouseLeave={ hideMe } onMouseMove={ ({ pageX, pageY }) => {
showMe({
left: pageX + 20, top: pageY,
content: `“More Content! More!”,`,
})
}}>Move your pointer to it.</button> )}
</LayerContext>
<Layer id="lightbox">{(_, { content, top, left }) => // will be rendered into <LayerStackMountPoint />
<div style={{ position: "fixed" }}>
<div style={{
top, left, position: "absolute",
padding: '10px',
background: 'rgba(0,0,0,0.7)', color: '#fff', borderRadius: '5px',
boxShadow: '0px 0px 50px 0px rgba(0,0,0,0.60)'}}>
{ content }
</div>
</div>
}</Layer>
</div>
)
Another option could be use one of dozens complete implementations with different properties:
https://js.coach/?search=popover
More examples
https://github.com/fckt/react-layer-stack/blob/master/demo/src/Demo.js
Live demo
https://fckt.github.io/react-layer-stack/
Installation
npm install --save react-layer-stack
API
<LayerStackMountPoint />
This is mount point for Layers
.
id: string
- you can have multiple LayerStackMountPoint
which could have different ID's.
children: callback({ views, displaying, show: callback(id, args), hide, hideAll, mountPointId, mountPointArgs }): ReactElement
- you can choose different strategies how to render Layers
in LayerStackMountPoint
instead of the default one.
<Layer />
id: string
- a Layer identificator
initialArgs
- initial arguments for a Layer
use: array
- array with context variables. Useful if you want to re-render the Layer if parent variables (closure) are changed
children: callback({ isActive, showMe: callback(args), showOnlyMe, hideMe, hideAll }, ...args): ReactElement
- will be rendered into
<LayerContext />
id: string
- a Layer identificator which LayerContext corresponds to
children: callback({ isActive, showMe: callback(args), showOnlyMe, hideMe, hideAll }): ReactElement
- will be mounted (rendered) directly to its parent
Store layers in your redux store
react-layer-stack
provides reducer
(import { reducer } from 'react-layer-stack'
) which you can combine into your Redux store instead of using preconfigured LayerStackProvider
. This is useful if you want to store everything in one store (which is good practice).
Real-world usage example
Public API consist 2 key components: Layer
, LayerStackMountPoint
and 1 additional: LayerContext
(sometimes toggle needs to know which popover is open now).
Set the LayerStackMountPoint
somewhere on the top of the tree:
import { LayerStackProvider, LayerStackMountPoint } from 'react-layer-stack'
return (
<LayerStackProvider>
<Container>
<LayerStackMountPoint />
<AppBar />
<Container className={styles.container}>
{children}
</Container>
</Container>
</LayerStackProvider>
)
Define your Layer
. This example shows how to propagate variables from lexical context (https://developer.mozilla.org/en/docs/Web/JavaScript/Closures) to the Layer
, which will be displayed in the LayerStackMountPoint
. Each layer should have an id
and use
properties. use
property is needed to determine if we should update the lexical context of the anonymous function which renders Modal
into Layer
if Cell
is re-rendered.
import { Layer, LayerContext } from 'react-layer-stack'
const modalId = 'DeleteObjectConfirmation' + objects[rowIndex].id
return (
<Cell {...props}>
// the layer definition. The content will show up in the LayerStackMountPoint when `show(modalId)` be fired in LayerContext
<Layer use={[objects[rowIndex], rowIndex]} id={modalId}> {({
hideMe, // alias for `hide(modalId)`
index } // useful to know to set zIndex, for example
, e) => // access to the arguments (click event data in this example)
<Modal onClick={ hideMe } zIndex={(index + 1) * 1000}>
<ConfirmationDialog
title={ 'Delete' }
message={ "You're about to delete to " + '"' + objects[rowIndex].name + '"' }
confirmButton={ <Button type="primary">DELETE</Button> }
onConfirm={ this.handleDeleteObject.bind(this, objects[rowIndex].name, hideMe) } // hide after confirmation
close={ hideMe } />
</Modal> }
</Layer>
// this is the toggle for Layer with `id === modalId` can be defined everywhere in the components tree
<LayerContext id={ modalId }> {({showMe}) => // showMe is alias for `show(modalId)`
<div style={styles.iconOverlay} onClick={ (e) => showMe(e) }> // additional arguments can be passed (like event)
<Icon type="trash" />
</div> }
</LayerContext>
</Cell>)
Alternatives
The is a lot of alternative ways to archive the desirable bottom-to-up link b/w components.
The most obvious (and naiive as well) way is to use redux (or another flux/data lib) as a transport to send data from one DOM branch to another. It's good and robust solution (moreover react-layer-stack use redux as a store currently), but the problem is that it's overkill. It's not universal also, consumes time to implement and grasp, not because of complications, but because you have to reinvent the same pattern again and again (slightly different in each case).
Another solution is to use on of ready-to-use components. But lot of times are you need slightly different behavior/look and more productive to implement home-grown ad-hock solution.
And the last option is to find library like https://github.com/tajo/react-portal or https://react-bootstrap.github.io/react-overlays/, designed to address the needs of bottom-to-up communication. These libs are often quite opinionated to their cases and doesn't solve the problem in its roots. react-layer-stack aims to give an answer how to organize bottom-to-up communication in the most natural, reasonable and flexible way.
The future
Obviously there is a lot of applications for the Layer API (https://github.com/fckt/react-layer-stack/blob/master/README.md#layer-). The cautious question is: could be it become a foundation or standard API to declare some kind of "universal" React "modules"? If so, could be the entire application become a "module"?
Images to understand the whole thing
View layers stack
Layer id and "use" property (sym/soft link)
TODO: