Trying to make a component in Vue.js, which first shows image via thumbnail, loading full image in background, and when loaded, show full image.
The thing which does not work, component does not react on change of showThumb flag in watch section. What is wrong?
Vue.component('page-image',
{
props: ['data'],
template:
'<img v-if="showThumb == true" v-bind:src="thumbSrc"></img>'+
'<img v-else v-bind:src="fullSrc"></img>',
data: function()
{
return { thumbSrc: '', fullSrc: '', showThumb: true };
},
watch:
{
data: function()
{
this.thumbSrc = data.thumbImg.url;
this.fullSrc = data.fullImg.url;
this.showThumb = true;
var imgElement = new Image();
imgElement.src = this.fullSrc;
imgElement.onload = (function()
{
this.showThumb = false; // <<-- this part is broken
} );
}
}
} );
Note: there is a reason why I do it via 2 img tags - this example is simplified.
Your onload callback will have a different scope than the surrounding watch function, so you cannot set your data property like this. Change it to an arrow function to keep scope:
imgElement.onload = () =>
{
this.showThumb = false;
};
See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/Arrow_functions
Related
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'm facing an issue where the events happening in the owl carousel does not update data values outside of the function
This is my code:
endScenario: function() {
$(".owl-carousel").on('changed.owl.carousel', function(e) {
this.carouselIndex = e.item.index;
var numCarouselItems = $('.carousel__item').length - 1;
if (numCarouselItems === this.carouselIndex) {
this.isEndingActive = true
}
console.log(this.carouselIndex)
console.log(this.numCarouselItems)
console.log("this is inside the owl function : " + this.isEndingActive)
});
console.log("this is outside the owl function : " + this.isEndingActive)
}
data: {
isEndingActive: false,
}
The user is supposed to scroll through the carousel and when the user is at the final slide of the carousel, it will trigger the endScenario function which suppose to update the isEndingActive: false -> true but when the requirement is fulfil, it does not trigger the change from false to true. Is there a reason why and how do I rectify this?
it seems the usage of this
the outside this is not equal the inside this
you can resolve it by arrow function
$(".owl-carousel").on('changed.owl.carousel', e => {}
or you can save a variable
endScenario: function() {
const self = this;
$(".owl-carousel").on('changed.owl.carousel', function(e){
//use self replace this
});
}
I am trying to change the value of an hidden input with vue js. I added a v-model to the input and I am trying to update it in a method.
My input looks like this:
<input type="hidden" name="payment_method" v-model="payment_method">
My vue js:
data: function() {
return {
name: '',
payment_method: '',
.
.
.
methods: {
submitAddPaymentMethod(){
window.stripe.handleCardSetup(
this.clientSecret, card, {
payment_method_data: {
//billing_details: { name: cardHolderName.value }
}
}
).then(function(result) {
if(result.error) {
var errorElement = document.getElementById('card-errors');
errorElement.textContent = result.error.message;
} else {
// has no effect on my input
this.payment_method = result.setupIntent.payment_method;
this.$refs.form.submit();
}
}.bind(this));
Maybe someone has an idea how to do this. Would appreciate that!
Best
You are getting a different this in the promise callback than the one you're expecting.
Use fat arrow to solve this.
.then(result => {
if(result.error) {
var errorElement = document.getElementById('card-errors');
errorElement.textContent = result.error.message;
} else {
// has no effect on my input
this.payment_method = result.setupIntent.payment_method;
this.$refs.form.submit();
}
}
I needed to add nextick() to wait for the DOM to be updated.
I am trying to implement font-awesome-picker to a website that i am making using vue2/php/mysql, but within standard js scripting, so no imports, .vue etc.
The script i am trying to add is taken from here: https://github.com/laistomazz/font-awesome-picker
The problem that i am facing is that i have 3 columns that have a title and an icon picker next it, that will allow the user to select 1 icon for each title. It is kinda working well...but if the same icon is used in 2 different columns then any time the user clicks again any of the 2 icons both instances of the picker will fire up, thus showing 2 popups. I need to somehow make them unique.
I've tried using
:key="list.id"
or
v-for="icon in icons" :icon:icon :key="icon"
but nothing worked. Somehow i have to separate all the instances (i think) so they are unique.
This is the template code:
Vue.component('font-awesome-picker', {
template: ' <div><div class="iconPicker__header"><input type="text" class="form-control" :placeholder="searchPlaceholder" #keyup="filterIcons($event)" #blur="resetNew" #keydown.esc="resetNew"></div><div class="iconPicker__body"><div class="iconPicker__icons"><i :class="\'fa \'+icon"></i></div></div></div>',
name: 'fontAwesomePicker',
props: ['seachbox','parentdata'],
data () {
return {
selected: '',
icons,
listobj: {
type: Object
}
};
},
computed: {
searchPlaceholder () {
return this.seachbox || 'search box';
},
},
methods: {
resetNew () {
vm.addNewTo = null;
},
getIcon (icon) {
this.selected = icon;
this.getContent(this.selected);
},
getContent (icon) {
const iconContent = window
.getComputedStyle(document.querySelector(`.fa.${icon}`), ':before')
.getPropertyValue('content');
this.convert(iconContent);
},
convert (value) {
const newValue = value
.charCodeAt(1)
.toString(10)
.replace(/\D/g, '');
let hexValue = Number(newValue).toString(16);
while (hexValue.length < 4) {
hexValue = `0${hexValue}`;
}
this.selecticon(hexValue.toUpperCase());
},
selecticon (value) {
this.listobj = this.$props.parentdata;
const result = {
className: this.selected,
cssValue: value,
listobj: this.listobj
};
this.$emit('selecticon', result);
},
filterIcons (event) {
const search = event.target.value.trim();
let filter = [];
if (search.length > 3) {
filter = icons.filter((item) => {
const regex = new RegExp(search, 'gi');
return item.match(regex);
});
}else{
this.icons = icons;
}
if (filter.length > 0) {
this.icons = filter;
}
}
},
});
I've setup a fiddle with the problem here:
https://jsfiddle.net/3yxk1ahb/1/
Just pick the same icon in both cases, and then click any of the icons again. You'll see that the popups opens for both columns.
How can i separate the pickers ?
problem is in your #click and v-show
you should use list.id instead of list.icon (i.e #click="addNewTo = list.id")
working fiddle https://jsfiddle.net/q513mhwt/
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