Lit-Element - Can't get Id of item from Object - polymer-3.x

I am learning lit-element and have run into a small problem I am trying to setup the ability to remove an Item from my list but I am unable to get the id of my Item it is coming across as undefined when I test it with console.log. I have three components the add-item.js which adds items to the list that is working fine. app.js is the main component that handles the auto refresh of the page aswell as the main rendering of the page this is where I have the event listeners for the addItem and the removeItem. Then I have todo-item component which is where I have the object that I am trying to get the ID for the remove functionality. Im at a loss at what I am doing wrong here and was hoping some one could take a look and point me in the right direction
here is the code so far .
add-item.js
```
import {LitElement, html} from 'lit-element';
class AddItem extends LitElement{
static get properties(){
return{
todoList: Array,
todoItem: String
}
}
constructor(){
super();
this.todoItem = '';
}
inputKeypress(e){
if(e.keyCode == 13){
e.target.value="";
this.onAddItem();
}else{
this.todoItem = e.target.value;
}
}
onAddItem(){
if(this.todoItem.length > 0){
let storedTodoList = JSON.parse(localStorage.getItem('todo-
list'));
storedTodoList = storedTodoList === null ? [] : storedTodoList;
storedTodoList.push({
id: new Date().valueOf(),
item: this.todoItem,
done: false
});
localStorage.setItem('todo-list',
JSON.stringify(storedTodoList));
this.dispatchEvent(new CustomEvent('addItem',{
bubbles: true,
composed: true,
detail: {
todoList: storedTodoList
}
}));
this.todoItem = '';
}
}
render(){
return html `
<div>
<input value=${this.todoItem}
#keyup="${(e) => this.inputKeypress(e)}">
</input>
<button #click="${() => this.onAddItem()}">Add Item</button>
</div>
`;
}
}
customElements.define('add-item', AddItem)
```
app.js
```
import {LitElement, html} from 'lit-element';
import './add-item';
import './list-items';
class TodoApp extends LitElement{
static get properties(){
return{
todoList: Array
}
}
constructor(){
super();
let list = JSON.parse(localStorage.getItem('todo-list'));
this.todoList = list === null ? [] : list;
}
firstUpdated(){
this.addEventListener('addItem', (e) => {
this.todoList = e.detail.todoList;
});
this.addEventListener('removeItem', (e) => {
let index = this.todoList.map(function(item) {return
item.id}).indexOf(e.detail.itemId);
this.todoList.splice(index, 1);
this.todoList = _.clone(this.todoList);
localStorage.setItem('todo-list', JSON.stringify(this.todoList));
})
}
render(){
return html `
<h1>Hello todo App</h1>
<add-item></add-item>
<list-items .todoList=${this.todoList}></list-items>
`;
}
}
customElements.define('todo-app', TodoApp)
```
todo-item.js
```
import {LitElement, html} from 'lit-element';
class TodoItem extends LitElement{
static get properties(){
return{
todoItem: Object
}
}
constructor(){
super();
this.todoItem = {};
}
onRemove(id){
this.dispatchEvent(new CustomEvent('removeItem',{
bubbles: true,
composed: true,
detail:{
itemId: id
}
}));
}
render(){
console.log(this.todoItem.id);
return html `<li>${this.todoItem}</li>
<button #click="${() =>
this.onRemove(this.todoItem.id)}">Remove</button>`;
}
}
customElements.define('todo-item', TodoItem);
```
I am looking to get the Id of the item so that I can remove it from the list for example if i have 5 items, one, two , three , four, five and I click the button to remove the third Item it should be removed and the list updated with the remaining items .. right now it is deleting the items but it is the last one on the list which is what I do not want to happen.
Looking forward to some help on this so that I can move forward with the project
thank you .

The issues has been resolved,
I was not supplying the entire array, just one element. After fixing the code I was able to get the Id of the object and move forward with my project as expected.

Related

detect click outside of react component [duplicate]

I'm looking for a way to detect if a click event happened outside of a component, as described in this article. jQuery closest() is used to see if the target from a click event has the dom element as one of its parents. If there is a match the click event belongs to one of the children and is thus not considered to be outside of the component.
So in my component, I want to attach a click handler to the window. When the handler fires I need to compare the target with the dom children of my component.
The click event contains properties like "path" which seems to hold the dom path that the event has traveled. I'm not sure what to compare or how to best traverse it, and I'm thinking someone must have already put that in a clever utility function... No?
The following solution uses ES6 and follows best practices for binding as well as setting the ref through a method.
To see it in action:
Hooks Implementation
Class Implementation After React 16.3
Class Implementation Before React 16.3
Hooks Implementation:
import React, { useRef, useEffect } from "react";
/**
* Hook that alerts clicks outside of the passed ref
*/
function useOutsideAlerter(ref) {
useEffect(() => {
/**
* Alert if clicked on outside of element
*/
function handleClickOutside(event) {
if (ref.current && !ref.current.contains(event.target)) {
alert("You clicked outside of me!");
}
}
// Bind the event listener
document.addEventListener("mousedown", handleClickOutside);
return () => {
// Unbind the event listener on clean up
document.removeEventListener("mousedown", handleClickOutside);
};
}, [ref]);
}
/**
* Component that alerts if you click outside of it
*/
export default function OutsideAlerter(props) {
const wrapperRef = useRef(null);
useOutsideAlerter(wrapperRef);
return <div ref={wrapperRef}>{props.children}</div>;
}
Class Implementation:
After 16.3
import React, { Component } from "react";
/**
* Component that alerts if you click outside of it
*/
export default class OutsideAlerter extends Component {
constructor(props) {
super(props);
this.wrapperRef = React.createRef();
this.handleClickOutside = this.handleClickOutside.bind(this);
}
componentDidMount() {
document.addEventListener("mousedown", this.handleClickOutside);
}
componentWillUnmount() {
document.removeEventListener("mousedown", this.handleClickOutside);
}
/**
* Alert if clicked on outside of element
*/
handleClickOutside(event) {
if (this.wrapperRef && !this.wrapperRef.current.contains(event.target)) {
alert("You clicked outside of me!");
}
}
render() {
return <div ref={this.wrapperRef}>{this.props.children}</div>;
}
}
Before 16.3
import React, { Component } from "react";
/**
* Component that alerts if you click outside of it
*/
export default class OutsideAlerter extends Component {
constructor(props) {
super(props);
this.setWrapperRef = this.setWrapperRef.bind(this);
this.handleClickOutside = this.handleClickOutside.bind(this);
}
componentDidMount() {
document.addEventListener("mousedown", this.handleClickOutside);
}
componentWillUnmount() {
document.removeEventListener("mousedown", this.handleClickOutside);
}
/**
* Set the wrapper ref
*/
setWrapperRef(node) {
this.wrapperRef = node;
}
/**
* Alert if clicked on outside of element
*/
handleClickOutside(event) {
if (this.wrapperRef && !this.wrapperRef.contains(event.target)) {
alert("You clicked outside of me!");
}
}
render() {
return <div ref={this.setWrapperRef}>{this.props.children}</div>;
}
}
I was stuck on the same issue. I am a bit late to the party here, but for me this is a really good solution. Hopefully it will be of help to someone else. You need to import findDOMNode from react-dom
import ReactDOM from 'react-dom';
// ... ✂
componentDidMount() {
document.addEventListener('click', this.handleClickOutside, true);
}
componentWillUnmount() {
document.removeEventListener('click', this.handleClickOutside, true);
}
handleClickOutside = event => {
const domNode = ReactDOM.findDOMNode(this);
if (!domNode || !domNode.contains(event.target)) {
this.setState({
visible: false
});
}
}
React Hooks Approach (16.8 +)
You can create a reusable hook called useComponentVisible.
import { useState, useEffect, useRef } from 'react';
export default function useComponentVisible(initialIsVisible) {
const [isComponentVisible, setIsComponentVisible] = useState(initialIsVisible);
const ref = useRef(null);
const handleClickOutside = (event) => {
if (ref.current && !ref.current.contains(event.target)) {
setIsComponentVisible(false);
}
};
useEffect(() => {
document.addEventListener('click', handleClickOutside, true);
return () => {
document.removeEventListener('click', handleClickOutside, true);
};
}, []);
return { ref, isComponentVisible, setIsComponentVisible };
}
Then in the component you wish to add the functionality to do the following:
const DropDown = () => {
const { ref, isComponentVisible } = useComponentVisible(true);
return (
<div ref={ref}>
{isComponentVisible && (<p>Dropdown Component</p>)}
</div>
);
}
Find a codesandbox example here.
2021 Update:
It has bee a while since I added this response, and since it still seems to garner some interest, I thought I would update it to a more current React version. On 2021, this is how I would write this component:
import React, { useState } from "react";
import "./DropDown.css";
export function DropDown({ options, callback }) {
const [selected, setSelected] = useState("");
const [expanded, setExpanded] = useState(false);
function expand() {
setExpanded(true);
}
function close() {
setExpanded(false);
}
function select(event) {
const value = event.target.textContent;
callback(value);
close();
setSelected(value);
}
return (
<div className="dropdown" tabIndex={0} onFocus={expand} onBlur={close} >
<div>{selected}</div>
{expanded ? (
<div className={"dropdown-options-list"}>
{options.map((O) => (
<div className={"dropdown-option"} onClick={select}>
{O}
</div>
))}
</div>
) : null}
</div>
);
}
Original Answer (2016):
Here is the solution that best worked for me without attaching events to the container:
Certain HTML elements can have what is known as "focus", for example input elements. Those elements will also respond to the blur event, when they lose that focus.
To give any element the capacity to have focus, just make sure its tabindex attribute is set to anything other than -1. In regular HTML that would be by setting the tabindex attribute, but in React you have to use tabIndex (note the capital I).
You can also do it via JavaScript with element.setAttribute('tabindex',0)
This is what I was using it for, to make a custom DropDown menu.
var DropDownMenu = React.createClass({
getInitialState: function(){
return {
expanded: false
}
},
expand: function(){
this.setState({expanded: true});
},
collapse: function(){
this.setState({expanded: false});
},
render: function(){
if(this.state.expanded){
var dropdown = ...; //the dropdown content
} else {
var dropdown = undefined;
}
return (
<div className="dropDownMenu" tabIndex="0" onBlur={ this.collapse } >
<div className="currentValue" onClick={this.expand}>
{this.props.displayValue}
</div>
{dropdown}
</div>
);
}
});
After trying many methods here, I decided to use github.com/Pomax/react-onclickoutside because of how complete it is.
I installed the module via npm and imported it into my component:
import onClickOutside from 'react-onclickoutside'
Then, in my component class I defined the handleClickOutside method:
handleClickOutside = () => {
console.log('onClickOutside() method called')
}
And when exporting my component I wrapped it in onClickOutside():
export default onClickOutside(NameOfComponent)
That's it.
Hook implementation based on Tanner Linsley's excellent talk at JSConf Hawaii 2020:
useOuterClick API
const Client = () => {
const innerRef = useOuterClick(ev => {/*event handler code on outer click*/});
return <div ref={innerRef}> Inside </div>
};
Implementation
function useOuterClick(callback) {
const callbackRef = useRef(); // initialize mutable ref, which stores callback
const innerRef = useRef(); // returned to client, who marks "border" element
// update cb on each render, so second useEffect has access to current value
useEffect(() => { callbackRef.current = callback; });
useEffect(() => {
document.addEventListener("click", handleClick);
return () => document.removeEventListener("click", handleClick);
function handleClick(e) {
if (innerRef.current && callbackRef.current &&
!innerRef.current.contains(e.target)
) callbackRef.current(e);
}
}, []); // no dependencies -> stable click listener
return innerRef; // convenience for client (doesn't need to init ref himself)
}
Here is a working example:
/*
Custom Hook
*/
function useOuterClick(callback) {
const innerRef = useRef();
const callbackRef = useRef();
// set current callback in ref, before second useEffect uses it
useEffect(() => { // useEffect wrapper to be safe for concurrent mode
callbackRef.current = callback;
});
useEffect(() => {
document.addEventListener("click", handleClick);
return () => document.removeEventListener("click", handleClick);
// read most recent callback and innerRef dom node from refs
function handleClick(e) {
if (
innerRef.current &&
callbackRef.current &&
!innerRef.current.contains(e.target)
) {
callbackRef.current(e);
}
}
}, []); // no need for callback + innerRef dep
return innerRef; // return ref; client can omit `useRef`
}
/*
Usage
*/
const Client = () => {
const [counter, setCounter] = useState(0);
const innerRef = useOuterClick(e => {
// counter state is up-to-date, when handler is called
alert(`Clicked outside! Increment counter to ${counter + 1}`);
setCounter(c => c + 1);
});
return (
<div>
<p>Click outside!</p>
<div id="container" ref={innerRef}>
Inside, counter: {counter}
</div>
</div>
);
};
ReactDOM.render(<Client />, document.getElementById("root"));
#container { border: 1px solid red; padding: 20px; }
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.12.0/umd/react.production.min.js" integrity="sha256-Ef0vObdWpkMAnxp39TYSLVS/vVUokDE8CDFnx7tjY6U=" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.12.0/umd/react-dom.production.min.js" integrity="sha256-p2yuFdE8hNZsQ31Qk+s8N+Me2fL5cc6NKXOC0U9uGww=" crossorigin="anonymous"></script>
<script> var {useRef, useEffect, useCallback, useState} = React</script>
<div id="root"></div>
Key points
useOuterClick makes use of mutable refs to provide lean Client API
stable click listener for lifetime of containing component ([] deps)
Client can set callback without needing to memoize it by useCallback
callback body has access to the most recent props and state - no stale closure values
(Side note for iOS)
iOS in general treats only certain elements as clickable. To make outer clicks work, choose a different click listener than document - nothing upwards including body. E.g. add a listener on the React root div and expand its height, like height: 100vh, to catch all outside clicks. Source: quirksmode.org
[Update] Solution with React ^16.8 using Hooks
CodeSandbox
import React, { useEffect, useRef, useState } from 'react';
const SampleComponent = () => {
const [clickedOutside, setClickedOutside] = useState(false);
const myRef = useRef();
const handleClickOutside = e => {
if (!myRef.current.contains(e.target)) {
setClickedOutside(true);
}
};
const handleClickInside = () => setClickedOutside(false);
useEffect(() => {
document.addEventListener('mousedown', handleClickOutside);
return () => document.removeEventListener('mousedown', handleClickOutside);
});
return (
<button ref={myRef} onClick={handleClickInside}>
{clickedOutside ? 'Bye!' : 'Hello!'}
</button>
);
};
export default SampleComponent;
Solution with React ^16.3:
CodeSandbox
import React, { Component } from "react";
class SampleComponent extends Component {
state = {
clickedOutside: false
};
componentDidMount() {
document.addEventListener("mousedown", this.handleClickOutside);
}
componentWillUnmount() {
document.removeEventListener("mousedown", this.handleClickOutside);
}
myRef = React.createRef();
handleClickOutside = e => {
if (!this.myRef.current.contains(e.target)) {
this.setState({ clickedOutside: true });
}
};
handleClickInside = () => this.setState({ clickedOutside: false });
render() {
return (
<button ref={this.myRef} onClick={this.handleClickInside}>
{this.state.clickedOutside ? "Bye!" : "Hello!"}
</button>
);
}
}
export default SampleComponent;
None of the other answers here worked for me. I was trying to hide a popup on blur, but since the contents were absolutely positioned, the onBlur was firing even on the click of inner contents too.
Here is an approach that did work for me:
// Inside the component:
onBlur(event) {
// currentTarget refers to this component.
// relatedTarget refers to the element where the user clicked (or focused) which
// triggered this event.
// So in effect, this condition checks if the user clicked outside the component.
if (!event.currentTarget.contains(event.relatedTarget)) {
// do your thing.
}
},
Hope this helps.
I found a solution thanks to Ben Alpert on discuss.reactjs.org. The suggested approach attaches a handler to the document but that turned out to be problematic. Clicking on one of the components in my tree resulted in a rerender which removed the clicked element on update. Because the rerender from React happens before the document body handler is called, the element was not detected as "inside" the tree.
The solution to this was to add the handler on the application root element.
main:
window.__myapp_container = document.getElementById('app')
React.render(<App/>, window.__myapp_container)
component:
import { Component, PropTypes } from 'react';
import ReactDOM from 'react-dom';
export default class ClickListener extends Component {
static propTypes = {
children: PropTypes.node.isRequired,
onClickOutside: PropTypes.func.isRequired
}
componentDidMount () {
window.__myapp_container.addEventListener('click', this.handleDocumentClick)
}
componentWillUnmount () {
window.__myapp_container.removeEventListener('click', this.handleDocumentClick)
}
/* using fat arrow to bind to instance */
handleDocumentClick = (evt) => {
const area = ReactDOM.findDOMNode(this.refs.area);
if (!area.contains(evt.target)) {
this.props.onClickOutside(evt)
}
}
render () {
return (
<div ref='area'>
{this.props.children}
</div>
)
}
}
MUI has a small component to solve this problem: https://mui.com/base/react-click-away-listener/ that you can cherry-pick it. It weights below 1 kB gzipped, it supports mobile, IE 11, and portals.
The Ez way... (UPDATED 2022)
Create a hook: useOutsideClick.ts
export function useOutsideClick(ref: any, onClickOut: () => void){
useEffect(() => {
const onClick = ({target}: any) => !ref.contains(target) && onClickOut?.()
document.addEventListener("click", onClick);
return () => document.removeEventListener("click", onClick);
}, []);
}
Add componentRef to your component and call useOutsideClick
export function Example(){
const componentRef = useRef();
useOutsideClick(componentRef.current!, () => {
// do something here
});
return (
<div ref={componentRef as any}> My Component </div>
)
}
Alternatively:
const onClickOutsideListener = () => {
alert("click outside")
document.removeEventListener("click", onClickOutsideListener)
}
...
return (
<div
onMouseLeave={() => {
document.addEventListener("click", onClickOutsideListener)
}}
>
...
</div>
with typescript
function Tooltip(): ReactElement {
const [show, setShow] = useState(false);
const ref = useRef<HTMLDivElement>(null);
useEffect(() => {
function handleClickOutside(event: MouseEvent): void {
if (ref.current && !ref.current.contains(event.target as Node)) {
setShow(false);
}
}
// Bind the event listener
document.addEventListener('mousedown', handleClickOutside);
return () => {
// Unbind the event listener on clean up
document.removeEventListener('mousedown', handleClickOutside);
};
});
return (
<div ref={ref}></div>
)
}
import { useClickAway } from "react-use";
useClickAway(ref, () => console.log('OUTSIDE CLICKED'));
For those who need absolute positioning, a simple option I opted for is to add a wrapper component that is styled to cover the whole page with a transparent background. Then you can add an onClick on this element to close your inside component.
<div style={{
position: 'fixed',
top: '0', right: '0', bottom: '0', left: '0',
zIndex: '1000',
}} onClick={() => handleOutsideClick()} >
<Content style={{position: 'absolute'}}/>
</div>
As it is right now if you add a click handler on content, the event will also be propagated to the upper div and therefore trigger the handlerOutsideClick. If this is not your desired behavior, simply stop the event progation on your handler.
<Content style={{position: 'absolute'}} onClick={e => {
e.stopPropagation();
desiredFunctionCall();
}}/>
`
Here is my approach (demo - https://jsfiddle.net/agymay93/4/):
I've created special component called WatchClickOutside and it can be used like (I assume JSX syntax):
<WatchClickOutside onClickOutside={this.handleClose}>
<SomeDropdownEtc>
</WatchClickOutside>
Here is code of WatchClickOutside component:
import React, { Component } from 'react';
export default class WatchClickOutside extends Component {
constructor(props) {
super(props);
this.handleClick = this.handleClick.bind(this);
}
componentWillMount() {
document.body.addEventListener('click', this.handleClick);
}
componentWillUnmount() {
// remember to remove all events to avoid memory leaks
document.body.removeEventListener('click', this.handleClick);
}
handleClick(event) {
const {container} = this.refs; // get container that we'll wait to be clicked outside
const {onClickOutside} = this.props; // get click outside callback
const {target} = event; // get direct click event target
// if there is no proper callback - no point of checking
if (typeof onClickOutside !== 'function') {
return;
}
// if target is container - container was not clicked outside
// if container contains clicked target - click was not outside of it
if (target !== container && !container.contains(target)) {
onClickOutside(event); // clicked outside - fire callback
}
}
render() {
return (
<div ref="container">
{this.props.children}
</div>
);
}
}
This already has many answers but they don't address e.stopPropagation() and preventing clicking on react links outside of the element you wish to close.
Due to the fact that React has it's own artificial event handler you aren't able to use document as the base for event listeners. You need to e.stopPropagation() before this as React uses document itself. If you use for example document.querySelector('body') instead. You are able to prevent the click from the React link. Following is an example of how I implement click outside and close.
This uses ES6 and React 16.3.
import React, { Component } from 'react';
class App extends Component {
constructor(props) {
super(props);
this.state = {
isOpen: false,
};
this.insideContainer = React.createRef();
}
componentWillMount() {
document.querySelector('body').addEventListener("click", this.handleClick, false);
}
componentWillUnmount() {
document.querySelector('body').removeEventListener("click", this.handleClick, false);
}
handleClick(e) {
/* Check that we've clicked outside of the container and that it is open */
if (!this.insideContainer.current.contains(e.target) && this.state.isOpen === true) {
e.preventDefault();
e.stopPropagation();
this.setState({
isOpen: false,
})
}
};
togggleOpenHandler(e) {
e.preventDefault();
this.setState({
isOpen: !this.state.isOpen,
})
}
render(){
return(
<div>
<span ref={this.insideContainer}>
<a href="#open-container" onClick={(e) => this.togggleOpenHandler(e)}>Open me</a>
</span>
<a href="/" onClick({/* clickHandler */})>
Will not trigger a click when inside is open.
</a>
</div>
);
}
}
export default App;
Typescript with Hooks
Note: I'm using React version 16.3, with React.createRef. For other versions use the ref callback.
Dropdown component:
interface DropdownProps {
...
};
export const Dropdown: React.FC<DropdownProps> () {
const ref: React.RefObject<HTMLDivElement> = React.createRef();
const handleClickOutside = (event: MouseEvent) => {
if (ref && ref !== null) {
const cur = ref.current;
if (cur && !cur.contains(event.target as Node)) {
// close all dropdowns
}
}
}
useEffect(() => {
// Bind the event listener
document.addEventListener("mousedown", handleClickOutside);
return () => {
// Unbind the event listener on clean up
document.removeEventListener("mousedown", handleClickOutside);
};
});
return (
<div ref={ref}>
...
</div>
);
}
I did this partly by following this and by following the React official docs on handling refs which requires react ^16.3. This is the only thing that worked for me after trying some of the other suggestions here...
class App extends Component {
constructor(props) {
super(props);
this.inputRef = React.createRef();
}
componentWillMount() {
document.addEventListener("mousedown", this.handleClick, false);
}
componentWillUnmount() {
document.removeEventListener("mousedown", this.handleClick, false);
}
handleClick = e => {
/*Validating click is made inside a component*/
if ( this.inputRef.current === e.target ) {
return;
}
this.handleclickOutside();
};
handleClickOutside(){
/*code to handle what to do when clicked outside*/
}
render(){
return(
<div>
<span ref={this.inputRef} />
</div>
)
}
}
Simply with ClickAwayListener from mui (material-ui):
<ClickAwayListener onClickAway={handleClickAway}>
{children}
<ClickAwayListener >
for more info you can check:https://mui.com/base/react-click-away-listener/
To extend on the accepted answer made by Ben Bud, if you are using styled-components, passing refs that way will give you an error such as "this.wrapperRef.contains is not a function".
The suggested fix, in the comments, to wrap the styled component with a div and pass the ref there, works.
Having said that, in their docs they already explain the reason for this and the proper use of refs within styled-components:
Passing a ref prop to a styled component will give you an instance of the StyledComponent wrapper, but not to the underlying DOM node. This is due to how refs work. It's not possible to call DOM methods, like focus, on our wrappers directly.
To get a ref to the actual, wrapped DOM node, pass the callback to the innerRef prop instead.
Like so:
<StyledDiv innerRef={el => { this.el = el }} />
Then you can access it directly within the "handleClickOutside" function:
handleClickOutside = e => {
if (this.el && !this.el.contains(e.target)) {
console.log('clicked outside')
}
}
This also applies for the "onBlur" approach:
componentDidMount(){
this.el.focus()
}
blurHandler = () => {
console.log('clicked outside')
}
render(){
return(
<StyledDiv
onBlur={this.blurHandler}
tabIndex="0"
innerRef={el => { this.el = el }}
/>
)
}
This is my way of solving the problem
I return a boolean value from my custom hook, and when this value changes (true if the click was outside of the ref that I passed as an arg), this way i can catch this change with an useEffect hook, i hope it's clear for you.
Here's a live example:
Live Example on codesandbox
import { useEffect, useRef, useState } from "react";
const useOutsideClick = (ref) => {
const [outsieClick, setOutsideClick] = useState(null);
useEffect(() => {
const handleClickOutside = (e) => {
if (!ref.current.contains(e.target)) {
setOutsideClick(true);
} else {
setOutsideClick(false);
}
setOutsideClick(null);
};
document.addEventListener("mousedown", handleClickOutside);
return () => {
document.removeEventListener("mousedown", handleClickOutside);
};
}, [ref]);
return outsieClick;
};
export const App = () => {
const buttonRef = useRef(null);
const buttonClickedOutside = useOutsideClick(buttonRef);
useEffect(() => {
// if the the click was outside of the button
// do whatever you want
if (buttonClickedOutside) {
alert("hey you clicked outside of the button");
}
}, [buttonClickedOutside]);
return (
<div className="App">
<button ref={buttonRef}>click outside me</button>
</div>
);
}
Typescript + simplified version of #ford04's proposal:
useOuterClick API
const Client = () => {
const ref = useOuterClick<HTMLDivElement>(e => { /* Custom-event-handler */ });
return <div ref={ref}> Inside </div>
};
Implementation
export default function useOuterClick<T extends HTMLElement>(callback: Function) {
const callbackRef = useRef<Function>(); // initialize mutable ref, which stores callback
const innerRef = useRef<T>(null); // returned to client, who marks "border" element
// update cb on each render, so second useEffect has access to current value
useEffect(() => { callbackRef.current = callback; });
useEffect(() => {
document.addEventListener("click", _onClick);
return () => document.removeEventListener("click", _onClick);
function _onClick(e: any): void {
const clickedOutside = !(innerRef.current?.contains(e.target));
if (clickedOutside)
callbackRef.current?.(e);
}
}, []); // no dependencies -> stable click listener
return innerRef; // convenience for client (doesn't need to init ref himself)
}
So I faced a similar problem but in my case the selected answer here wasn't working because I had a button for the dropdown which is, well, a part of the document. So clicking the button also triggered the handleClickOutside function. To stop that from triggering, I had to add a new ref to the button and this !menuBtnRef.current.contains(e.target) to the conditional. I'm leaving it here if someone is facing the same issue like me.
Here's how the component looks like now:
const Component = () => {
const [isDropdownOpen, setIsDropdownOpen] = useState(false);
const menuRef = useRef(null);
const menuBtnRef = useRef(null);
const handleDropdown = (e) => {
setIsDropdownOpen(!isDropdownOpen);
}
const handleClickOutside = (e) => {
if (menuRef.current && !menuRef.current.contains(e.target) && !menuBtnRef.current.contains(e.target)) {
setIsDropdownOpen(false);
}
}
useEffect(() => {
document.addEventListener('mousedown', handleClickOutside, true);
return () => {
document.removeEventListener('mousedown', handleClickOutside, true);
};
}, []);
return (
<button ref={menuBtnRef} onClick={handleDropdown}></button>
<div ref={menuRef} className={`${isDropdownOpen ? styles.dropdownMenuOpen : ''}`}>
// ...dropdown items
</div>
)
}
My biggest concern with all of the other answers is having to filter click events from the root/parent down. I found the easiest way was to simply set a sibling element with position: fixed, a z-index 1 behind the dropdown and handle the click event on the fixed element inside the same component. Keeps everything centralized to a given component.
Example code
#HTML
<div className="parent">
<div className={`dropdown ${this.state.open ? open : ''}`}>
...content
</div>
<div className="outer-handler" onClick={() => this.setState({open: false})}>
</div>
</div>
#SASS
.dropdown {
display: none;
position: absolute;
top: 0px;
left: 0px;
z-index: 100;
&.open {
display: block;
}
}
.outer-handler {
position: fixed;
top: 0;
left: 0;
right: 0;
bottom: 0;
opacity: 0;
z-index: 99;
display: none;
&.open {
display: block;
}
}
componentWillMount(){
document.addEventListener('mousedown', this.handleClickOutside)
}
handleClickOutside(event) {
if(event.path[0].id !== 'your-button'){
this.setState({showWhatever: false})
}
}
Event path[0] is the last item clicked
I used this module (I have no association with the author)
npm install react-onclickout --save
const ClickOutHandler = require('react-onclickout');
class ExampleComponent extends React.Component {
onClickOut(e) {
if (hasClass(e.target, 'ignore-me')) return;
alert('user clicked outside of the component!');
}
render() {
return (
<ClickOutHandler onClickOut={this.onClickOut}>
<div>Click outside of me!</div>
</ClickOutHandler>
);
}
}
It did the job nicely.
UseOnClickOutside Hook - React 16.8 +
Create a general useOnOutsideClick function
export const useOnOutsideClick = handleOutsideClick => {
const innerBorderRef = useRef();
const onClick = event => {
if (
innerBorderRef.current &&
!innerBorderRef.current.contains(event.target)
) {
handleOutsideClick();
}
};
useMountEffect(() => {
document.addEventListener("click", onClick, true);
return () => {
document.removeEventListener("click", onClick, true);
};
});
return { innerBorderRef };
};
const useMountEffect = fun => useEffect(fun, []);
Then use the hook in any functional component.
const OutsideClickDemo = ({ currentMode, changeContactAppMode }) => {
const [open, setOpen] = useState(false);
const { innerBorderRef } = useOnOutsideClick(() => setOpen(false));
return (
<div>
<button onClick={() => setOpen(true)}>open</button>
{open && (
<div ref={innerBorderRef}>
<SomeChild/>
</div>
)}
</div>
);
};
Link to demo
Partially inspired by #pau1fitzgerald answer.
In my DROPDOWN case the Ben Bud's solution worked well, but I had a separate toggle button with an onClick handler. So the outside clicking logic conflicted with the button onClick toggler. Here is how I solved it by passing the button's ref as well:
import React, { useRef, useEffect, useState } from "react";
/**
* Hook that triggers onClose when clicked outside of ref and buttonRef elements
*/
function useOutsideClicker(ref, buttonRef, onOutsideClick) {
useEffect(() => {
function handleClickOutside(event) {
/* clicked on the element itself */
if (ref.current && !ref.current.contains(event.target)) {
return;
}
/* clicked on the toggle button */
if (buttonRef.current && !buttonRef.current.contains(event.target)) {
return;
}
/* If it's something else, trigger onClose */
onOutsideClick();
}
// Bind the event listener
document.addEventListener("mousedown", handleClickOutside);
return () => {
// Unbind the event listener on clean up
document.removeEventListener("mousedown", handleClickOutside);
};
}, [ref]);
}
/**
* Component that alerts if you click outside of it
*/
export default function DropdownMenu(props) {
const wrapperRef = useRef(null);
const buttonRef = useRef(null);
const [dropdownVisible, setDropdownVisible] = useState(false);
useOutsideClicker(wrapperRef, buttonRef, closeDropdown);
const toggleDropdown = () => setDropdownVisible(visible => !visible);
const closeDropdown = () => setDropdownVisible(false);
return (
<div>
<button onClick={toggleDropdown} ref={buttonRef}>Dropdown Toggler</button>
{dropdownVisible && <div ref={wrapperRef}>{props.children}</div>}
</div>
);
}
I had a similar use case where I had to develop a custom dropdown menu. it should close automatically when the user clicks outside. here is the recent React Hooks implementation-
import { useEffect, useRef, useState } from "react";
export const App = () => {
const ref = useRef();
const [isMenuOpen, setIsMenuOpen] = useState(false);
useEffect(() => {
const checkIfClickedOutside = (e) => {
// If the menu is open and the clicked target is not within the menu,
// then close the menu
if (isMenuOpen && ref.current && !ref.current.contains(e.target)) {
setIsMenuOpen(false);
}
};
document.addEventListener("mousedown", checkIfClickedOutside);
return () => {
// Cleanup the event listener
document.removeEventListener("mousedown", checkIfClickedOutside);
};
}, [isMenuOpen]);
return (
<div className="wrapper" ref={ref}>
<button
className="button"
onClick={() => setIsMenuOpen((oldState) => !oldState)}
>
Click Me
</button>
{isMenuOpen && (
<ul className="list">
<li className="list-item">dropdown option 1</li>
<li className="list-item">dropdown option 2</li>
<li className="list-item">dropdown option 3</li>
<li className="list-item">dropdown option 4</li>
</ul>
)}
</div>
);
}
An example with Strategy
I like the provided solutions that use to do the same thing by creating a wrapper around the component.
Since this is more of a behavior I thought of Strategy and came up with the following.
I'm new with React and I need a bit of help in order to save some boilerplate in the use cases
Please review and tell me what you think.
ClickOutsideBehavior
import ReactDOM from 'react-dom';
export default class ClickOutsideBehavior {
constructor({component, appContainer, onClickOutside}) {
// Can I extend the passed component's lifecycle events from here?
this.component = component;
this.appContainer = appContainer;
this.onClickOutside = onClickOutside;
}
enable() {
this.appContainer.addEventListener('click', this.handleDocumentClick);
}
disable() {
this.appContainer.removeEventListener('click', this.handleDocumentClick);
}
handleDocumentClick = (event) => {
const area = ReactDOM.findDOMNode(this.component);
if (!area.contains(event.target)) {
this.onClickOutside(event)
}
}
}
Sample Usage
import React, {Component} from 'react';
import {APP_CONTAINER} from '../const';
import ClickOutsideBehavior from '../ClickOutsideBehavior';
export default class AddCardControl extends Component {
constructor() {
super();
this.state = {
toggledOn: false,
text: ''
};
this.clickOutsideStrategy = new ClickOutsideBehavior({
component: this,
appContainer: APP_CONTAINER,
onClickOutside: () => this.toggleState(false)
});
}
componentDidMount () {
this.setState({toggledOn: !!this.props.toggledOn});
this.clickOutsideStrategy.enable();
}
componentWillUnmount () {
this.clickOutsideStrategy.disable();
}
toggleState(isOn) {
this.setState({toggledOn: isOn});
}
render() {...}
}
Notes
I thought of storing the passed component lifecycle hooks and override them with methods simillar to this:
const baseDidMount = component.componentDidMount;
component.componentDidMount = () => {
this.enable();
baseDidMount.call(component)
}
component is the component passed to the constructor of ClickOutsideBehavior.
This will remove the enable/disable boilerplate from the user of this behavior but it doesn't look very nice though

Angular: How to filter a dataTable using query params

I want to filter my table using query params that I got from the user input in another component.
I am able to get the data that the users send through the input and print it to the console.log. But I don't know how to use it to filter the table.
i have built a filter but for some reason i cant call it.
This is my filter :
import { Pipe, PipeTransform } from "#angular/core";
import { Container } from "./Entites/Container";
#Pipe({
name: 'textFilter'
})
export class textFilter implements PipeTransform {
transform(
containers : Container[],
storageSearch?: any,
clientSearch?: string,
): Container[] {
if (!containers) return [];
if (!storageSearch) return containers;
storageSearch = storageSearch.toLocaleLowerCase();
containers = [...containers.filter(user => user.TAOR_QTSR_EBRI.toLocaleLowerCase() === storageSearch)];
if (!clientSearch) return containers;
clientSearch = clientSearch.toLocaleLowerCase();
containers = [...containers.filter(user => user.LQOCH_SHM_LEOZI_QTSR.toLocaleLowerCase() === clientSearch)];
// if (!roleSearch) return users;
//roleSearch = roleSearch.toLocaleLowerCase();
//users = [...users.filter(user => user.role.toLocaleLowerCase() === roleSearch)];
return containers;
}
}
This is my component ngOnInit i have some other filters there, for example checkbox filter :
ngOnInit() {
this.marinService.getAllContainers().subscribe((result) => {
//Data
this.dataSource = new MatTableDataSource(result);
//Paginator
this.dataSource.paginator = this.paginator;
//AutoFilter Form 1st page
this.clientType = this.route.snapshot.queryParamMap.get('clientType');
this.storageType= this.route.snapshot.queryParamMap.get('storageTypes');
console.log('The Client name is : '+this.clientType+' '+'The storage Facility is : '+this.storageType);
//CheckBox Filter
this.dataSource.filterPredicate = (data: Container, filter: any) => {
return filter.split(',').every((item: any) => data.SOG_MCOLH.indexOf(item) !== -1);
};
this.filterCheckboxes.subscribe((newFilterValue: any[]) => {
this.dataSource.filter = newFilterValue.join(',');
});
});
}
What I want to accomplish is to be able to filter the table using the query params.
We can pass the data which you have received as input (in the parent component) to the material table filtering function applyFilter inside the child component...
relevant parent TS:
import { Component } from '#angular/core';
#Component({
selector: 'app-root',
styles: [`.parent{background:lightgreen; padding:2%;}`],
template: `
Enter string for filtering: <input type='text' [(ngModel)]='inputStr' />
<!-- {{inputStr}} -->
<table-filtering-example [inputStr]='inputStr'>loading</table-filtering-example>
`,
})
export class AppComponent {
inputStr: string = '';
constructor() { }
}
relevant child TS:
export class TableFilteringExample implements OnInit, OnChanges {
displayedColumns: string[] = ['position', 'name', 'weight', 'symbol'];
dataSource = new MatTableDataSource(ELEMENT_DATA);
#Input() inputStr:string;
constructor(){}
ngOnInit(){}
ngOnChanges(){
/* just call the applyFilter button with the data which is passed to your component from it's parent */console.log("(ngOnChanges)this.inputStr:", this.inputStr);
this.applyFilter(this.inputStr);
}
applyFilter(filterValue: string) {
this.dataSource.filter = filterValue.trim().toLowerCase();
}
}
complete working stackblitz here

lit-element passing data from one component to another

I am currently learning how to user lit-element v2.0.0-rc.2 I have two components app.js and list-items.js. In app.js I am collecting data from local storage and storing it in this.todoList, Im then calling this.todoList in my list-items.js but the problem I am running into is that it is not passing the data as an array but as an object, I am trying to output that data in list-items all Im getting when I do a console.log of this.todoList is [object] in my tags it is rendering out with dots for the tag but no data. I was wondering If i could get some help in understanding why this is happening . here is my code
app.js
'''
import {LitElement, html} from 'lit-element';
import './add-item';
import './list-items';
class TodoApp extends LitElement{
static get properties(){
return{
todoList: Array
}
}
constructor(){
super();
let list = JSON.parse(localStorage.getItem('todo-list'));
this.todoList = list === null ? [] : list;
}
render(){
return html `
<h1>Hello todo App</h1>
<add-item></add-item>
<list-items todoList=${this.todoList}></list-items>
`;
}
}
customElements.define('todo-app', TodoApp)
list-items.js
import { LitElement, html } from 'lit-element';
import {repeat} from 'lit-html/directives/repeat.js';
import './todo-item';
class ListItems extends LitElement {
static get properties(){
return{
todoList: Array
}
}
constructor(){
super();
this.todoList = [];
}
render(){
console.log(this.todoList)
return html `
<ul>${repeat(this.todoList, (todo) => html`<todo-item
todoItem=${todo.item}></todo-item`)}</ul>
`;
}
}
customElements.define('list-items', ListItems);
'''
the result I am looking for is the for the data stored in local storage to be listed on my rendered page.
Attributes are always text. Because todoList an array, it's a property, not attribute. Try binding as a property: .todoList="${this.todoList}". See https://lit-element.polymer-project.org/guide/templates#bind-properties-to-child-elements (Updated link for Lit, https://lit.dev/docs/templates/expressions/#property-expressions)

react-native navigating between screens from non component class

I'm trying to navigate between react native screens from my Backend class like this:
var self = this;
firebase.auth().onAuthStateChanged((user) => {
if (user) {
self.setState({
userID: user.uid,
})
} else{
self.props.navigation.navigate("Login");
}
});
My backend class is not a component and therefore is not imported into the stack navigator I am using. I am getting an error saying 'self.props.navigation is not an object'.
Does anyone know I can fix this? Thanks
One not-so-good practice is to define your Navigator as a static/class variable of your App instance:
const MyNavigator = StackNavigator(...);
export default class MyApp extends Component {
render() {
return <MyNavigator ref={(ref) => MyApp.Navigator = ref}/>
}
}
then you can access your navigator and it's props and functions anywhere you want! (for example dispatch a back event):
import MyApp from '...';
MyApp.Navigator.dispatch(NavigationActions.back());
I am personally not a fan of navigation actions happening at that level however, sometimes it's necessary. Expanding on the answer from #Dusk a pattern was made known to me that helps with this very solution. You can find it here
https://github.com/react-community/react-navigation/issues/1439#issuecomment-303661539
The idea is that you create a service that holds a ref to your navigator. Now from anywhere in your app you can import that service and have access to your navigator. It keeps it clean and concise.
If you are using react-navigation then you can achieve this via Navigation Service
Create a file named NavigationService and add the below code there
import { NavigationActions, StackActions } from 'react-navigation';
let navigator;
function setTopLevelNavigator(navigatorRef) {
navigator = navigatorRef;
}
function navigate(routeName, params) {
navigator.dispatch(
NavigationActions.navigate({
routeName,
params
})
);
}
function goBack(routeName, params) {
navigator.dispatch(
StackActions.reset({
index: 0,
actions: [
NavigationActions.navigate({
routeName,
params
})
]
})
);
}
function replace(routeName, params) {
navigator.dispatch(
StackActions.replace({
index: 0,
actions: [
NavigationActions.navigate({
routeName,
params
})
]
})
);
}
function pop() {
navigator.dispatch(StackActions.pop());
}
function popToTop() {
navigator.dispatch(StackActions.popToTop());
}
// add other navigation functions that you need and export them
export default {
navigate,
goBack,
replace,
pop,
popToTop,
setTopLevelNavigator
};
Now import this file in your app.js and set the TopLevelNavigator, your app.js will look something like this
import React, { Component } from 'react';
import NavigationService from './routes/NavigationService';
export default class App extends Component {
constructor() {
super();
}
render() {
return (
<View style={{ flex: 1, backgroundColor: '#fff' }}>
<AppNavigator
ref={navigatorRef => {
NavigationService.setTopLevelNavigator(navigatorRef);
}}
/>
</View>
);
}
}
Now you are good to go, you can import your NavigationService where ever you want, you can use it like this in any of the components and non-component files
import NavigationService from 'path to the NavigationService file';
/* you can use any screen name you have defined in your StackNavigators
* just replace the LogInScreen with your screen name and it will work like a
* charm
*/
NavigationService.navigate('LogInScreen');
/*
* you can also pass params or extra data into the ongoing screen like this
*/
NavigationService.navigate('LogInScreen',{
orderId: this.state.data.orderId
});

React props using Meteor Apollo

I am playing with the Meteor Apollo demo repo.
I am having difficulty passing variables down to children with React. I am getting an error
imports/ui/Container.jsx:10:6: Unexpected token (10:6)
The below code is the Container.jsx component:
import React from 'react';
import { Accounts } from 'meteor/std:accounts-ui';
class Container extends React.Component {
render() {
let userId = this.props.userId;
let currentUser = this.props.currentUser;
}
return (
<Accounts.ui.LoginForm />
{ userId ? (
<div>
<pre>{JSON.stringify(currentUser, null, 2)}</pre>
<button onClick={() => currentUser.refetch()}>Refetch!</button>
</div>
) : 'Please log in!' }
);
}
}
It is passed props via the Meteor Apollo data system (I have omitted some imports at the top):
const App = ({ userId, currentUser }) => {
return (
<div>
<Sidebar />
<Header />
<Container userId={userId} currentUser={currentUser} />
</div>
)
}
// This container brings in Apollo GraphQL data
const AppWithData = connect({
mapQueriesToProps({ ownProps }) {
if (ownProps.userId) {
return {
currentUser: {
query: `
query getUserData ($id: String!) {
user(id: $id) {
emails {
address
verified
}
randomString
}
}
`,
variables: {
id: ownProps.userId,
},
},
};
}
},
})(App);
// This container brings in Tracker-enabled Meteor data
const AppWithUserId = createContainer(() => {
return {
userId: Meteor.userId(),
};
}, AppWithData);
export default AppWithUserId;
I would really appreciate some pointers.
I believe the error is that you accidentally ended the render function before the return statement.
render() { // <- here it starts
let userId = this.props.userId;
let currentUser = this.props.currentUser;
} // <- here it ends
Another error is that your return statement doesn't return a single DOM element, but two of them: an Accounts.ui.LoginForm and a div. The return function should only return one element. Just put the entire thing into a single <div>.

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