EDIT: It worked by adding prevent modifier to the element in the template
I'm working on a slider that changes the slides on wheel event, I'm throttling the event to get it work just one time on each scroll, I have this piece of code
<div
ref="animated-figure"
class="animated-figure-wrapper"
>
<h1 class="animated-figure__caption">YOU</h1>
</div>
mounted() {
this.$refs['animated-figure'].addEventListener('wheel', this.throttle(this.scrollDirection, 800));
},
methods: {
throttle(func, interval) {
let lastCall = 0;
return function() {
const now = Date.now();
if (lastCall + interval < now) {
lastCall = now;
return func.apply(this, arguments);
}
};
},
scrollDirection(e) {
e.preventDefault();
e.wheelDeltaY > 0
? console.log("DOWN")
: console.log("UP")
e.stopImmediatePropagation();
}
}
Prevent default here is not working as intended and it's continue scrolling, any ideas?
Related
I'm trying to build a calendar in which you can scroll. I would like to achieve the scrolling also by dragging. So I use EventListeners.
mousemove continuously triggers, after the first mousedown, even if I already released the mouse. So the removeEventListeners don't really work. I don't quite understand what's wrong or how to get the interactions between all Listeners to work correctly.
Here is my CodeSandBox
mounted() {
this.initScrollCalendar()
},
methods: {
initScrollCalendar() {
const calendar = this.$refs.calendar
calendar.scrollLeft = this.position.left;
calendar.addEventListener('mousedown', (e) => this.mouseDownHandler())
},
mouseDownHandler() {
const calendar = this.$refs.calendar
calendar.addEventListener('mousemove', (e) => this.mouseMoveHandler(e) )
calendar.addEventListener('mouseup', this.mouseUpHandler());
},
mouseMoveHandler(e) {
console.log("Move")
const calendar = this.$refs.calendar
const rect = calendar.getBoundingClientRect()
const clientX = e.clientX - rect.left
const dx = clientX - this.position.x
calendar.scrollLeft = this.position.left + dx
},
mouseUpHandler() {
console.log("Up")
const calendar = this.$refs.calendar
calendar.removeEventListener('mousemove', (e) => this.mouseMoveHandler(e));
calendar.removeEventListener('mouseup', this.mouseUpHandler());
}
}
I ended up using vue-dragscroll. Works like a charm and the setup is totally simple. If needed, I can also set a starting position of my scroll container.
Don't forget overflow: auto in css
<div ref="scrollContainer" v-dragscroll>
...
</div>
// Setting starting point
const scrollContainer = this.$refs.scrollContainer
scrollContainer.scrollLeft = 500;
Ask for help from the community. For two weeks I can not overcome the problem with repeated firing of 'mooveend' in the project. I have tried all the advice given here. Here's what I've read and researched already, but it didn't work for me.
This is one of the tips:
moveend event fired many times when page is load with Leaflet
<template>
<div id="map"></div>
</template>
<script>
export default {
name: "ObjectMapView",
props: ['coordinate'],
data: function () {
return {
map: null,
addressPoints: null,
markers: null,
}
},
mounted: function() {
this.initializedMap();
},
watch: {
coordinate: function (val) {
this.run();
}
},
methods: {
initializedMap: function () {
this.map = L.map('map').setView([52.5073390000,5.4742833000], 13);
L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', {
attribution: '© OpenStreetMap contributors'
}).addTo(this.map);
this.markers = L.markerClusterGroup();
},
run: function () {
var map = this.map;
var markers = this.markers;
var getAllObjects = this.coordinate;
var getBoundsMarkers;
//Clearing Layers When Switching a Filter
markers.clearLayers();
this.addressPoints = getAllObjects.map(function (latlng){
return [latlng.latitude, latlng.longitude, latlng.zip, latlng.object_id, latlng.archived];
});
map.addLayer(markers);
//We give to the map only those coordinates that are in the zone of visibility of the map during the first
getBoundsMarkers = getAllObjects.filter((coord) => {
if(!coord.latitude && !coord.longitude){
return false;
}
return map.getBounds().contains(L.latLng(coord.latitude, coord.longitude));
});
/*
Responds to changing the boundaries of the map visibility zone and
transmits a list of coordinates that are in the visibility zone
*/
console.log('getAllObjects_1', getAllObjects);
map.on('moveend', function() {
console.log('moveend');
console.log('getAllObjects_2', getAllObjects);
getBoundsMarkers = getAllObjects.filter((coord) => {
if(!coord.latitude && !coord.longitude){
return false;
}
return map.getBounds().contains(L.latLng(coord.latitude, coord.longitude));
});
eventHub.$emit('sendMarkers', getBoundsMarkers);
});
// In the loop, we iterate over the coordinates and give them to the map
for (var i = 0; i < this.addressPoints.length; i++) {
var a = this.addressPoints[i];
var title = '' + a[2] + ''; //bubble
var marker = L.marker(new L.LatLng(a[0], a[1]), {
title: title
});
marker.bindPopup(title);
markers.addLayer(marker);
}
eventHub.$emit('sendMarkers', getBoundsMarkers);
}
}
}
</script>
<style scoped>
#map {
width: 97%;
height: 100%;
}
</style>
I figured it out myself.
The 'zoomend' and 'dragend' option didn't work for me. I searched a lot for a suitable option and realized that the "moveend" event fires several times because this event is created every time you move the map. Therefore it is necessary to stop this event. I got out of the situation in this way. Immediately after the map was initialized, I wrote:
map.off('moveend');
and for me it worked. Now it works fine. I will be very happy if this is useful to someone.
I am using element ui el-image. And I want to preview my image when clicked with (:preview-src-list). But When I click first time it doesnt preview anything. just add's my downloaded image. So I need to click 2 times. But I want to click 1 time.
Here is my template code:
<el-image :src="src"
:preview-src-list="srcList"
#click="imgClick"></el-image>
ts code:
src = null;
srcList = [];
product = 'shoe1';
imgClick() {
prevImg(product).then(resp => {
const url = window.URL.createObjectURL(new Blob([resp.data]));
this.srclist = [url];
});
}
#Watch("product")
changed(value) {
getProductImage(value).then(resp => {
const url = window.URL.createObjectURL(new Blob([resp.data]));
this.src = url;
}).catc(e => {
alert(e);
});
}
mounted() {
this.changed(product);
}
I think these things happen because when you click on that image it will trigger clickHandler:
...
clickHandler() {
// don't show viewer when preview is false
if (!this.preview) {
return;
}
...
}
...
From source
And the preview is the computed property:
...
preview() {
const { previewSrcList } = this;
return Array.isArray(previewSrcList) && previewSrcList.length > 0;
}
...
From source
So nothing happened in the first click but after that you set preview-src-list and click it again then it works.
If you code is synchronous you can use event like mousedown which will trigger before click event.
<el-image
:src="url"
:preview-src-list="srcList"
#mousedown="loadImages">
</el-image>
Example
But if you code is asynchronous you can use refs and call clickHandler after that.
...
// fetch something
this.$nextTick(() => {
this.$refs.elImage.clickHandler()
})
...
Example
Hi I am new to vuejs and currently working on an application which requires the method to be called on Ctrl + z and Ctrl + y.
This is what I have tried till now
https://codesandbox.io/s/funny-sky-mqdg0?file=/src/components/HelloWorld.vue
Problem: keyup works only when I ctrl+z is pressed over the input, how do I make it work on div container or make it work on the particular page? is it possible in pure vuejs or i need to install any external library or use traditional event listener way? any suggestions would be helpful
<input #keyup.ctrl.90="method1()" />
<input #keyup.ctrl.89="method2()" />
You could set up a keyup handler for the whole page.
If you want to undo / redo data outside of an input, I think you have to save each change somewhere and then undo / redo it in the keyup handler.
<div>{{ output }}</div>
data () {
return {
changes: [],
output: ''
}
},
mounted () {
document.addEventListener('keyup', this.keyupHandler)
},
destroyed () {
document.removeEventListener('keyup', this.keyupHandler)
},
methods: {
logChange (string) {
this.changes.push(string)
}
keyupHandler (event) {
if (event.ctrlKey && event.key === 'z') {
this.undoHandler()
}
else if (event.ctrlKey && event.key === 'y') {
this.redoHandler()
}
},
undoHandler () {
// Get the data from "this.changes" and set the output
this.output = ...
},
redoHandler () {
// Get the data from "this.changes" and set the output
this.output = ...
}
}
I created a custom select2 input element for Vue 2.
My question is: why is
<select2 v-model="vacancy.staff_member_id" #input="update(vacancy)"></select2>
working, but
<select2 v-model="vacancy.staff_member_id" #change="update(vacancy)"></select2>
not?
Since normal <input> elements in Vue have a #change handler, it would be nice if my custom select2 input has the same.
Some information on my custom element:
The purpose of this element is to not render all <option> elements but only those needed, because we have many select2 inputs on one page and many options inside a select2 input, causing page load to become slow.
This solution makes it much faster.
Vue.component('select2', {
props: ['options', 'value', 'placeholder', 'config', 'disabled'],
template: '<select><slot></slot></select>',
data: function() {
return {
newValue: null
}
},
mounted: function () {
var vm = this;
$.fn.select2.amd.require([
'select2/data/array',
'select2/utils'
], function (ArrayData, Utils) {
function CustomData ($element, options) {
CustomData.__super__.constructor.call(this, $element, options);
}
Utils.Extend(CustomData, ArrayData);
CustomData.prototype.query = function (params, callback) {
if (params.term && params.term !== '') {
// search for term
var results;
var termLC = params.term.toLowerCase();
var length = termLC.length;
if (length < 3) {
// if only one or two characters, search for words in string that start with it
// the string starts with the term, or the term is used directly after a space
results = _.filter(vm.options, function(option){
return option.text.substr(0,length).toLowerCase() === termLC ||
_.includes(option.text.toLowerCase(), ' '+termLC.substr(0,2));
});
}
if (length > 2 || results.length < 2) {
// if more than two characters, or the previous search give less then 2 results
// look anywhere in the texts
results = _.filter(vm.options, function(option){
return _.includes(option.text.toLowerCase(), termLC);
});
}
callback({results: results});
} else {
callback({results: vm.options}); // no search input -> return all options to scroll through
}
};
var config = {
// dataAdapter for displaying all options when opening the input
// and for filtering when the user starts typing
dataAdapter: CustomData,
// only the selected value, needed for un-opened display
// we are not using all options because that might become slow if we have many select2 inputs
data:_.filter(vm.options, function(option){return option.id === parseInt(vm.value);}),
placeholder:vm.placeholder
};
for (var attr in vm.config) {
config[attr] = vm.config[attr];
}
if (vm.disabled) {
config.disabled = vm.disabled;
}
if (vm.placeholder && vm.placeholder !== '') {
$(vm.$el).append('<option></option>');
}
$(vm.$el)
// init select2
.select2(config)
.val(vm.value)
.trigger('change')
// prevent dropdown to open when clicking the unselect-cross
.on("select2:unselecting", function (e) {
$(this).val('').trigger('change');
e.preventDefault();
})
// emit event on change.
.on('change', function () {
var newValue = $(this).val();
if (newValue !== null) {
Vue.nextTick(function(){
vm.$emit('input', newValue);
});
}
})
});
},
watch: {
value: function (value, value2) {
if (value === null) return;
var isChanged = false;
if (_.isArray(value)) {
if (value.length !== value2.length) {
isChanged = true;
} else {
for (var i=0; i<value.length; i++) {
if (value[i] !== value2[i]) {
isChanged = true;
}
}
}
} else {
if (value !== value2) {
isChanged = true;
}
}
if (isChanged) {
var selectOptions = $(this.$el).find('option');
var selectOptionsIds = _.map(selectOptions, 'value');
if (! _.includes(selectOptionsIds, value)) {
var missingOption = _.find(this.options, {id: value});
var missingText = _.find(this.options, function(opt){
return opt.id === parseInt(value);
}).text;
$(this.$el).append('<option value='+value+'>'+missingText+'</option>');
}
// update value only if there is a real change
// (without checking isSame, we enter a loop)
$(this.$el).val(value).trigger('change');
}
}
},
destroyed: function () {
$(this.$el).off().select2('destroy')
}
The reason is because you are listening to events on a component <select2> and not an actual DOM node. Events on components will refer to the custom events emitted from within, unless you use the .native modifier.
Custom events are different from native DOM events: they do not bubble up the DOM tree, and cannot be captured unless you use the .native modifier. From the docs:
Note that Vue’s event system is separate from the browser’s EventTarget API. Though they work similarly, $on and $emit are not aliases for addEventListener and dispatchEvent.
If you look into the code you posted, you will see this at the end of it:
Vue.nextTick(function(){
vm.$emit('input', newValue);
});
This code emits a custom event input in the VueJS event namespace, and is not a native DOM event. This event will be captured by v-on:input or #input on your <select2> VueJS component. Conversely, since no change event is emitted using vm.$emit, the binding v-on:change will never be fired and hence the non-action you have observed.
Terry pointed out the reason, but actually you can simply pass your update event to the child component as a prop. Check demo below.
Vue.component('select2', {
template: '<select #change="change"><option value="value1">Value 1</option><option value="value2">Value 2</option></select>',
props: [ 'change' ]
})
new Vue({
el: '#app',
methods: {
onChange() {
console.log('on change');
}
}
});
<script src="https://unpkg.com/vue#2.4.2/dist/vue.min.js"></script>
<div id="app">
<div>
<p>custom select</p>
<select2 :change="onChange"></select2>
</div>
<div>
<p>default select</p>
<select #change="onChange">
<option value="value1">Value 1</option>
<option value="value2">Value 2</option>
</select>
</div>
</div>
fiddle