How to use React DnD with styled component? - styled-components

When wrapping my styled component in connectDragSource I get the following error:
Uncaught Error: Only native element nodes can now be passed to React
DnD connectors.You can either wrap PaneItemText__StyledItem into a
<div>, or turn it into a drag source or a drop target itself.
The first suggestion from this message is to wrap my styled component in a <div>, but this will mess with my layout and would prefer not to do this.
I'm not sure what the second option is suggesting - would anybody be able to clarify?
Below is an rough example what I am doing:
import React, { Component } from 'react';
import styled from 'styled-components';
import { DragSource } from 'react-dnd';
const StyledComponent = syled.div`
...
`;
class MyComponent extends Component {
...
render() {
const { connectDragSource } = this.props;
return connectDragSource(<StyledComponent />)
}
}
const itemSource = {
beginDrag(props) {
/* code here */
},
endDrag(props) {
/* code here */
}
};
function collect(connect, monitor) {
return {
connectDragSource: connect.dragSource(),
isDragging: monitor.isDragging()
}
}
export default DragSource('foo', itemSource, collect(MyComponent);

You should use Styled Component's innerRef to get the underlying DOM node, then you can call your connectDragSource to it.
In your case, it should be like this:
class MyComponent extends Component {
...
render() {
const { connectDragSource } = this.props;
return (
<StyledComponent
innerRef={instance => connectDragSource(instance)}
/>
)
}
}
You can also look at my implementation of Knight component for the official chess tutorial as a reference.
It is also accessible through CodeSandbox.

If you are using multiple connectors you can do the following:
<MyStyledComponent
innerRef={instance => {
connectDragSource(instance);
connectDropTarget(instance);
}}
/>
Source: https://github.com/react-dnd/react-dnd/issues/347#issuecomment-221703726

Related

child property from parent Promise

I want to create a navigation component for my project. The shell fetches a json with chapter info, these are passed to nav-element, which recursively calls itself to render the navigation tree.
shell.js
import { LitElement, html, css } from 'lit-element';
import {until} from 'lit-html/directives/until.js';
import './nav-element.js';
export class Shell extends LitElement {
static get properties() {
return {
configjson : { type: Array }
};
}
constructor() {
super();
this.configjson = fetch('./src/convertjson_test.json').then(res => res.json());
}
render() {
return html`
<main>
some content
<nav-element .chapters=${until(this.configjson, [])} root></nav-element>
</main>
`;
}
}
customElements.define('shell', Shell);
nav-element.js
import { LitElement, html, css } from 'lit-element';
import {until} from 'lit-html/directives/until.js';
import {repeat} from 'lit-html/directives/repeat.js';
export class NavElement extends LitElement {
static get properties() {
return {
chapters: {type: Array},
root: {type: Boolean} //to mark the root node
};
}
static get styles() {
return css`
.navheader {
display: none;
}
.navheader[active] {
display: block;
}
`;
}
render() {
return html`
<div class="navHeader" ?active="${this.root}">header</div>
${until(repeat(this.chapters, (chapter) => chapter.pos, (chapter) => html`<div>${chapter.n}<nav-element .chapters=${chapter.c}></nav-element></div>`))}
`;
}
}
customElements.define('nav-element', NavElement);
The problem is, that the configjson Promise is passed as property and not yet resolved by the time the nav-element is called, so i get the error:
Uncaught (in promise) TypeError: this.chapters is undefined
Searched all lit-element and lit-html documentation, the until directive resolved the issue in the shell, but not in the nav-element.
The same coding pattern worked fine in Polymer 2 (&3, although with ajax instead of fetch). Does anyone know how to solve this using lit-element only?
There is a time frame between the construction of NavElement and the assignment of the chapters property where chapters is undefined. It might be safe to initialize chapters in the component itself rather than in Shell's until directive, or at least provide a fallback value in the template:
export class NavElement extends LitElement {
static get properties() {
return {
chapters: {type: Array},
// ...
};
}
constructor() {
super();
this.chapters = [];
}
// or
render() {
return html`
...
${repeat(this.chapters || [], chapter => ...)}
`;
}
}
Also, you've (correctly) declared the chapters property as an Array but you're wrapping the repeat directive in an until (as if it was a Promise I guess?). Here there are two things going on:
the repeat() call returns a DirectiveFn and not a Promise like until expects. If chapters was a Promise, the correct way to combine until and repeat would have been:
until(
this.chaptersPromise.then(chapters => repeat(chapters, chapter => html`...`)),
html`Loading...`,
)
but...
chapters is not a Promise: the until call in the parent component resolves it and passes the result.
As for the Shell component: until used in this way should work, however its intended use is to
Render placeholder content until the final content is available
[from lit-html docs]
To make the most of it, use it to temporarily render a loading template instead of <nav-element>:
render() {
return html`
${until(
this.configJson.then(chapters => html`<nav-element .chapters=${chapters}></nav-element>`),
html`Loading chapters`,
)}
`;
}
Also, not a big deal, but here the configJson property is declared as an Array but is actually a Promise.

React - accessing context in child components

I am using this react package - #spyna/react-store (link) in my project which is nothing but a wrapper for React Context API - createStore & withStore. But I am not able to access the react context api store values in my child component (which I set in the App component).
Actually when I try to access this.props.store.get("amount") I am getting an compilation error saying "props store does not exist". Please advise me on how to access the context in my child component. Thanks in advance.
App component:
import { createStore } from "#spyna/react-store";
class App extends React.Component<IAppProps> {
render() {
<Route component={this.ChildComponent} />
}
private ChildComponent= () => <Child1/>;
}
const initialValue = {
amount: 15,
username: {
name: "spyna",
url: "https://spyna.it"
}
};
export default createStore(App, initialValue);
Child component:
import { withStore } from "#spyna/react-store";
interface ICustomProps {
...
}
interface IAppProps {
...
}
class Child1 extends React.Component<ICustomProps & IAppProps, IAuthState> {
render() {
return (
<p>My Amount: {this.props.store.get('amount')}</p>
)
}
}
export default withStore(Child1)

How do you access a lit-element render root after overriding createRenderRoot?

I've been playing around with lit-element, and I want to grab my custom element to run a getElementById. The only examples I can find use the shadow root (since that's the recommended way to use lit-element). How do you get access to your custom element to run a query on just your element?
import { LitElement, html }
from 'https://unpkg.com/lit-element/lit-element.js?module';
class RenderRootTest extends LitElement {
constructor() {
super();
}
render () {
const renderRoot = this.shadowRoot; //Won't work, because I'm overriding the shadowroot
return html`
<div>Rendered</div>
${renderRoot ?
html`<div>Render root found</div>` :
html``
}
`;
}
createRenderRoot() {
return this;
}
}
customElements.define('render-root-test', RenderRootTest);
I found the answer myself after enough tinkering. You can either use this.renderRoot or just this. However, note that certain methods such as .getElementById don't seem to exist. If anyone has any additional details on this topic, I would appreciate it.
ex.
import { LitElement, html }
from 'https://unpkg.com/lit-element/lit-element.js?module';
class RenderRootTest extends LitElement {
constructor() {
super();
}
render () {
const renderRoot = this.renderRoot;
return html`
<div>Rendered</div>
${renderRoot ?
html`<div>Render root found</div>` :
html``
}
`;
}
createRenderRoot() {
return this;
}
}
customElements.define('render-root-test', RenderRootTest);
Just reference this which is the instance of the custom element. The shadowRoot is created and returned by LitElement's createRenderRoot() so if you don't create one and instead of this.shadowRoot return this--which is the node itself--that is what the content is rendered into, there is no shadowRoot.

How can I proxy (or define a middleware) to block/allow some method calls in my React Component?

Let's say I have a React Component like the following :
import React, { Component } from 'react';
class test extends Component {
__method01() {
//.... sime implentation
}
__method02(){
//.... sime implentation
}
render() {
return (
<div>
</div>
);
}
}
export default test;
What I want to achieve is to implement function that intercepts all or some methods call and avoid executing them under certain circumstances.
I was thinking about a Proxy pattern. But I'm not sure what could be the best (elegant) implementation for React.

How to use React DnD with styled component if the dragSource is also the dropTarget?

I have already found this question
How to use React DnD with styled component?
but In my particular case, it does not help me, because my dragSource is also my dropTarget.
like this:
class MyComponent extends Component {
...
render() {
const { connectDragSource, connectDropTarget, ... } = this.props;
return (
connectDragSource &&
connectDropTarget &&
connectDragSource(
connectDropTarget(
<MyStyledComponent>
<h1>foo</h1>
</MyStyledComponent>
)
)
);
}
}
So the question is: how can I use innerRef to call my connectDragSource AND my connectDropTarget.
You can use component's innerRef to get DOM node.
class MyComponent extends Component {
render() {
const { connectDragSource, connectDropTarget } = this.props;
return (
connectDragSource &&
connectDropTarget
<MyStyledComponent
innerRef={ref => {
this.props.connectDragSource(ref);
this.props.connectDropTarget(ref);
}}>
<h1>foo</h1>
</MyStyledComponent>
);
}
}

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