Problem:
I'm looking for a clean way to show a title tooltip on items that have a CSS ellipsis applied. (Within a React component)
What I've tried:
I setup a ref, but it doesn't exist until componentDidUpdate, so within componentDidUpdate I forceUpdate. (This needs some more rework to handle prop changes and such and I would probably use setState instead.) This kind of works but there are a lot of caveats that I feel are unacceptable.
setState/forceUpdate - Maybe this is a necessary evil
What if the browser size changes? Do I need to re-render with every resize? I suppose I'd need a debounce on that as well. Yuck.
Question:
Is there a more graceful way to accomplish this goal?
Semi-functional MCVE:
https://codepen.io/anon/pen/mjYzMM
class App extends React.Component {
render() {
return (
<div>
<Test message="Overflow Ellipsis" />
<Test message="Fits" />
</div>
);
}
}
class Test extends React.Component {
constructor(props) {
super(props);
this.element = React.createRef();
}
componentDidMount() {
this.forceUpdate();
}
doesTextFit = () => {
if (!this.element) return false;
if (!this.element.current) return false;
console.log(
"***",
"offsetWidth: ",
this.element.current.offsetWidth,
"scrollWidth:",
this.element.current.scrollWidth,
"doesTextFit?",
this.element.current.scrollWidth <= this.element.current.offsetWidth
);
return this.element.current.scrollWidth <= this.element.current.offsetWidth;
};
render() {
return (
<p
className="collapse"
ref={this.element}
title={this.doesTextFit() ? "it fits!" : "overflow"}
>
{this.props.message}
</p>
);
}
}
ReactDOM.render(<App />, document.getElementById("container"));
.collapse {
width:60px;
white-space: nowrap;
overflow: hidden;
text-overflow: ellipsis;
}
<script crossorigin src="https://unpkg.com/react#16/umd/react.production.min.js"></script>
<script crossorigin src="https://unpkg.com/react-dom#16/umd/react-dom.production.min.js"></script>
<div id="container"></div>
Since a lot of people are still viewing this question. I did finally figure out how to do it. I'll try to rewrite this into a working example at some point but here's the gist.
// Setup a ref
const labelRef = useRef(null);
// State for tracking if ellipsis is active
const [isEllipsisActive, setIsEllipsisActive] = useState(false);
// Setup a use effect
useEffect(() => {
if(labelRef?.current?.offsetWidth < labelRef?.current?.scrollWidth) {
setIsEllipsisActive(true);
}
}, [labelRef?.current, value, isLoading]); // I was also tracking if the data was loading
// Div you want to check if ellipsis is active
<div ref={labelRef}>{value}</div>
I use this framework agnostic snippet to this. Just include it on your page and see the magic happen ;)
(function() {
let lastMouseOverElement = null;
document.addEventListener("mouseover", function(event) {
let element = event.target;
if (element instanceof Element && element != lastMouseOverElement) {
lastMouseOverElement = element;
const style = window.getComputedStyle(element);
const whiteSpace = style.getPropertyValue("white-space");
const textOverflow = style.getPropertyValue("text-overflow");
if (whiteSpace == "nowrap" && textOverflow == "ellipsis" && element.offsetWidth < element.scrollWidth) {
element.setAttribute("title", element.textContent);
} else {
element.removeAttribute("title");
}
}
});
})();
From:
https://gist.github.com/JoackimPennerup/06592b655402d1d6181af32def40189d
Using ReactJS and GatsbyJS (v2) I have a header component that sits fixed over div id="outerContainer" in the parent layout component.
To toggle class on scroll position below 100px, I would generally use window.scrollY < 100.
However, due to the body class with the style overflow:hidden and outerContainer with overflow: scroll, the window scroll position does not change.
How can I define outerContainer.scrollY < 100 from a child component, whilst referencing the outerContainer of the parent for scroll position?
Layout.js
const Layout = ({ children }) => (
<div>
<div id="outerContainer" ref={el => (this.outerContainer = el)}>
<div className="content">{children}</div>
</div>
<Header />
</div>
);
Header.js
class Header extends React.Component {
constructor(props) {
super(props);
this.state = {
navScrolled: true
};
this.onScroll = this.onScroll.bind(this);
}
componentDidMount() {
document.addEventListener('scroll', () => {
const navScrolled = outerContainer.scrollY < 100;
if (navScrolled !== this.state.navScrolled) {
this.onScroll(navScrolled);
}
});
}
componentWillUnmount() {...}
...
}
My first thought is that I should perform function in layout.js and use props pass the state down. Is this the best option or perhaps is there another way that would keen everything in header.js?
Your first thought is correct, parent class is proper place for your onScroll callback, because the scroll position is a property of your entire layout, not of header which only uses it.
Also, by keeping onScroll in parent class, you keep yourself able to pass it to outerContainer as well, if it grows into separate class during the development, which is likely to happen.
I'm using Waypoint (7.3.2) in React (16) to try and create a list of scrollable items where each item fades to invisible as it reaches the top of the div. My basic question is how do I get a reference to the element that enters/leaves the waypoint in the event or callback?
I thought that by including ref={} in the element I wanted to get in the callback I would get a reference to the element and be able to change the opacity. The following is the code where Waypoint is plugged in:
class Division extends Component {
constructor(props) {
super(props);
}
_handleWayPointEnter = (event) => {
console.log("Waypoint enter " + JSON.stringify(event, 4));
}
_handleWayPointLeave = (event) => {
console.log("Waypoint leave " + JSON.stringify(event, 4));
}
render() {
let inlineStyle= {opacity : this.state.opacity};
return (
<Waypoint debug={false} onEnter={this._handleWayPointEnter} onLeave={this._handleWayPointLeave} >
<div style={inlineStyle} ref={this.props.innerRef} className="sch-division">
{this.props.name}<br/>
<SomeOtherComponent />
</div>
</Waypoint>
);
}
}
export default Division;
Any/all replies appreciated!
-- griff
From react-waypoint docs :
If you do pass a child, it can be a single DOM component (e.g. <div>)
or a composite component (e.g. <MyComponent />).
Waypoint needs a DOM node to compute its boundaries. When you pass a
DOM component to Waypoint, it handles getting a reference to the DOM
node through the ref prop automatically. If you pass a composite
component, you need to make use of the innerRef prop passed by
Waypoint to your component. Simply pass it through as the ref of a DOM
component and you're all set. Like in this example:
class Block extends React.Component {
render() {
return <div ref={this.props.innerRef}>Hello</div>
}
}
Block.propTypes = {
innerRef: PropTypes.func.isRequired,
}
const App = () => (
<Waypoint>
<Block />
</Waypoint>
)
Here you're using a single DOM component (<div>), i suggest you store your div ref like this :
<div style={inlineStyle} ref={(div) => { this.divinwaypoint = div; }} className="sch-division">
Then use it in your functions :
_handleWayPointEnter = (event) => {
console.log("Waypoint enter " + JSON.stringify(event, 4));
this.divinwaypoint.style.opacity = 0;
}
Edit: i'm not using waypoint but i think it should display your component ref in the event prop.
I have a Vue.js component with several elements in it. I want to automatically scroll to the bottom of that element when a method in the component is called.
Basically, do the same as this. However, I haven't found a way to get the element within my component and modify scrollTop
I'm currently using Vue.js 2.0.8.
2022 easy, readable, smooth scrolling ability, & won't hurt your brain... use el.scrollIntoView()
scrollIntoView() has options you can pass it like scrollIntoView({behavior: 'smooth'}) to get smooth scrolling out of the box and does not require any external libraries.
Here is a fiddle.
methods: {
scrollToElement() {
const el = this.$refs.scrollToMe;
if (el) {
// Use el.scrollIntoView() to instantly scroll to the element
el.scrollIntoView({behavior: 'smooth'});
}
}
}
Then if you wanted to scroll to this element on page load you could call this method like this:
mounted() {
this.scrollToElement();
}
Else if you wanted to scroll to it on a button click or some other action you could call it the same way:
<button #click="scrollToElement">scroll to me</button>
The scroll works all the way down to IE 8. The smooth scroll effect does not work out of the box in IE or Safari. If needed there is a polyfill available for this here as #mostafaznv mentioned in the comments.
As I understand, the desired effect you want is to scroll to the end of a list (or scrollable div) when something happens (e.g.: an item is added to the list). If so, you can scroll to the end of a container element (or even the page it self) using only pure JavaScript and the VueJS selectors.
var container = this.$el.querySelector("#container");
container.scrollTop = container.scrollHeight;
I've provided a working example in this fiddle.
Every time a item is added to the list, the list is scrolled to the end to show the new item.
I tried the accepted solution and it didn't work for me. I use the browser debugger and found out the actual height that should be used is the clientHeight BUT you have to put this into the updated() hook for the whole solution to work.
data(){
return {
conversation: [
{
}
]
},
mounted(){
EventBus.$on('msg-ctr--push-msg-in-conversation', textMsg => {
this.conversation.push(textMsg)
// Didn't work doing scroll here
})
},
updated(){ <=== PUT IT HERE !!
var elem = this.$el
elem.scrollTop = elem.clientHeight;
},
Use the ref attribute on the DOM element for reference
<div class="content scrollable" ref="msgContainer">
<!-- content -->
</div>
You need to setup a WATCH
data() {
return {
count: 5
};
},
watch: {
count: function() {
this.$nextTick(function() {
var container = this.$refs.msgContainer;
container.scrollTop = container.scrollHeight + 120;
});
}
}
Ensure you're using proper CSS
.scrollable {
overflow: hidden;
overflow-y: scroll;
height: calc(100vh - 20px);
}
Here is a simple example using ref to scroll to the bottom of a div.
/*
Defined somewhere:
var vueContent = new Vue({
el: '#vue-content',
...
*/
var messageDisplay = vueContent.$refs.messageDisplay;
messageDisplay.scrollTop = messageDisplay.scrollHeight;
<div id='vue-content'>
<div ref='messageDisplay' id='messages'>
<div v-for="message in messages">
{{ message }}
</div>
</div>
</div>
Notice that by putting ref='messageDisplay' in the HTML, you have access to the element through vueContent.$refs.messageDisplay
If you need to support IE11 and (old) Edge, you can use:
scrollToBottom() {
let element = document.getElementById("yourID");
element.scrollIntoView(false);
}
If you don't need to support IE11, the following will work (clearer code):
scrollToBottom() {
let element = document.getElementById("yourID");
element.scrollIntoView({behavior: "smooth", block: "end"});
}
Try vue-chat-scroll:
Install via npm: npm install --save vue-chat-scroll
Import:
import Vue from 'vue'
import VueChatScroll from 'vue-chat-scroll'
Vue.use(VueChatScroll)
in app.js after window.Vue = require('vue').default;
then use it with :
<ul class="messages" v-chat-scroll>
// your message/chat code...
</ul>
For those that haven't found a working solution above, I believe I have a working one. My specific use case was that I wanted to scroll to the bottom of a specific div - in my case a chatbox - whenever a new message was added to the array.
const container = this.$el.querySelector('#messagesCardContent');
this.$nextTick(() => {
// DOM updated
container.scrollTop = container.scrollHeight;
});
I have to use nextTick as we need to wait for the dom to update from the data change before doing the scroll!
I just put the above code in a watcher for the messages array, like so:
messages: {
handler() {
// this scrolls the messages to the bottom on loading data
const container = this.$el.querySelector('#messagesCard');
this.$nextTick(() => {
// DOM updated
container.scrollTop = container.scrollHeight;
});
},
deep: true,
},
The solution did not work for me but the following code works for me. I am working on dynamic items with class of message-box.
scrollToEnd() {
setTimeout(() => {
this.$el
.getElementsByClassName("message-box")
[
this.$el.getElementsByClassName("message-box").length -
1
].scrollIntoView();
}, 50);
}
Remember to put the method in mounted() not created() and add class message-box to the dynamic item. setTimeout() is essential for this to work. You can refer to https://forum.vuejs.org/t/getelementsbyclassname-and-htmlcollection-within-a-watcher/26478 for more information about this.
This is what worked for me
this.$nextTick(() => {
let scrollHeight = this.$refs.messages.scrollHeight
window.scrollTo(0, scrollHeight)
})
In the related question you posted, we already have a way to achieve that in plain javascript, so we only need to get the js reference to the dom node we want to scroll.
The ref attribute can be used to declare reference to html elements to make them available in vue's component methods.
Or, if the method in the component is a handler for some UI event, and the target is related to the div you want to scroll in space, you can simply pass in the event object along with your wanted arguments, and do the scroll like scroll(event.target.nextSibling).
I had the same need in my app (with complex nested components structure) and I unfortunately did not succeed to make it work.
Finally I used vue-scrollto that works fine !
My solutions without modules:
Template
<div class="scrollable-content" ref="conversations" />
Script
scrollToBottom() {
const container = this.$refs.conversations;
container.scrollTop = container.scrollHeight;
},
scrollToBottom() {
this.$nextTick(function () {
let BoxEl = document.querySelector('#Box');
if(BoxEl)
BoxEl.scrollTop = BoxEl.scrollHeight;
});
}
Agree with Lurein Perera
Just want to add extra info
watch: {
arrayName: {
handler() {
const container = this.$el.querySelector("#idName");
this.$nextTick(() => {
container.scrollTop = container.scrollHeight;
});
},
deep: true,
},
},
Where as:
arrayName = Name of array
idName = The id attribute has to be added to the div where you want the scrollbar to auto-scroll down when arrayName length increases.
scrollToElement() {
const element = this.$refs.abc; // here abc is the ref of the element
if (element) {
el.scrollIntoView({behavior: 'smooth'});
}
}
}
here you need to use ref for the particular div or element which you want make visible on scroll.
if you have a table and you want to locate the last row of the table then you have to use -
element.lastElementChild.scrollIntoView({behaviour:'smooth'})
Here not that if you ware asynchronously adding the element to the table then you have to take care of it. you can test it using setTimeout, if that is making any difference.
e.g.
const element = this.$refs.abc;
if (element) {
setTimeout(() => {
element.lastElementChild.scrollIntoView({behaviour:'smooth'})
}, 1000);
}
}
replace set timeout with your own async logic.
Using Composition API and TypeScript
I set the parameter scrollTop equal to scrollHeightfrom the HTMLDivElment API.
<template>
<div id="container" ref="comments">
Content ...
</div>
</template>
<script lang="ts">
import { defineComponent, ref, Ref, watchEffect } from 'vue'
export default defineComponent({
setup() {
const comments: Ref<null | HTMLDivElement> = ref(null)
watchEffect(() => {
if(comments.value) {
comments.value.scrollTop = comments.value.scrollHeight
}
})
return {
comments
}
}
})
</script>
I have a full screen landing page, and I want to know when that screen is full scrolled out, so I can bring in and fix the navbar. I am managing to get the hight of the device/window, but I can't get pageYOffset to fire of.
Here is my code:
export default class NavbarComp extends Component {
constructor() {
super();
this.state = {
windowHight:"",
navbarfix: ""
};
this.handleScroll = this.handleScroll.bind(this)
}
getWindowHight(){
let deviceWindow = document.getElementById('landing-section');
let deviceWindowHight = window.getComputedStyle(deviceWindow).getPropertyValue('height');
console.log("from getinitiatlhight" + deviceWindowHight);
this.setState({
windowHight: deviceWindowHight
});
}
componentDidMount(){
window.addEventListener('scroll', this.handleScroll);
this.getWindowHight();
}
handleScroll() {
console.log("scrolll" + this.state.windowHight);
if (window.pageYOffset >= this.state.windowHight) {
console.log("fix");
} else if (window.scrollY < this.state.windowHight) {
console.log("unfix" );
}
}
I don't really know much about React, but
this.handleScroll = this.handleScroll.bind(this)
doesn't seem right. handleScroll() isn't defined within the scope provided by this (hence why you're binding it after the fact. As such, shouldn't the code read:
this.handleScroll = handleScroll.bind(this)
The problem was
window.getComputedStyle(deviceWindow).getPropertyValue('height');
always return the value as a string like 2000px. But, you need that to be a integer to do comparison. So, use the following to get the height in numbers
let deviceWindowHight = deviceWindow.clientHeight
The rest should work fine.
Check this fiddle http://jsfiddle.net/Pranesh456/0ycfru3n/15/
Don't forget to open the console