I'm using the Vue Multiselect component, along with a list that displays suggested items.
I've basically got
selectedItems: []
allItems: []
onSelectOfItem(item) {
item.selected = true;
}
My HTML has the #select="onSelectOfItem" event which fires when multiselect picks an item, and it passes in the item.
I've also got a list of suggested items thats like
<li v-for="item in allItems" v-if="!item.selected"></li>
However when the onSelectOfItem method fires and I assign selected = true the v-for I have does not hide the item, however if I use the vue debug tools and inspect the data selected is set to false
If i add a #click="onSelectOfItem(item)" to the repeater, it works fine.
Id expect that changing the value on the object would update throughout, I'm from an Angular background which passes everything by reference, so no matter where i update item.selected from the whole UI will be in sync.
Why is the UI not reacting to the change within the object?? and how can I fix.
Thanks
Related
I'm trying to build a mobile small application using v-expansion-panels to display a list.
The idea is that when the user adds a new item in such list it will open the new panel and scroll down to such new panel.
I found a goTo() method in the $vuetify variable, unfortunatly the v-expansion-panels transition (the "opening") take some time and the goTo() won't completely scroll down because of the scrollbar height changes.
So from my understanding I need to detect the end of the transition (enter/afterEnter hook).
Per the vuetifyjs documentation, I could hope to have a "transition" property on my component. (Which isn't the case anyway). But such property is only a string so I can't hook into it.
My other idea is to, somehow, find the transition component and hook into it. Unfortunatly I have trouble understanding el/vnode and the way vuejs is building is tree like the vue-devtool show and I can't get the transition component. When debugging (in the enter hook callback of the transition) it is like the component/el/vnode has a parent but isn't the child of anybody.
Is there a way to do what I'm looking for?
Here is a jsfiddler of what I currently do: https://jsfiddle.net/kdgn80sb/
Basically it is the method I'm defining in the Vue:
methods: {
newAlarm: function() {
const newAlarmPanelIndex = this.alarms.length - 1;
this.alarms.push({title: "New line"});
this.activePanelIndex = newAlarmPanelIndex;
// TODO:
this.$vuetify.goTo(this.$refs.alarmPanels[newAlarmPanelIndex]);
}
}
Firstly you should open manually panel and then use goTo with a timeout.
It works for me, just give some time to a panel to open.
<v-expansion-panels v-model="alarmPanels">
<v-expansion-panel>
<div id="example" />
</v-expansion-panel>
</v-expansion-panels>
this.alarmPanels.push(0); // Use index of expansion-panel
setTimeout(() => {
this.$vuetify.goTo(`#${resultId}`);
}, 500);
When I have
data: {
pictures: [
'http://lorempixel.com/1920/1920?0',
'http://lorempixel.com/1920/1920?1',
'http://lorempixel.com/1920/1920?2',
'http://lorempixel.com/1920/1920?3',
'http://lorempixel.com/1920/1920?4',
'http://lorempixel.com/1920/1920?5',
'http://lorempixel.com/1920/1920?6',
'http://lorempixel.com/1920/1920?7',
'http://lorempixel.com/1920/1920?8',
'http://lorempixel.com/1920/1920?9',
]
}
it renders perfectly, but when I fetch the data and get it like this in the console and perfect data in the vue dev tools
["https://picsum.photos/id/1020/4288/2848",
"https://picsum.photos/id/1021/2048/1206",
"https://picsum.photos/id/1022/6000/3376",
"https://picsum.photos/id/1023/3955/2094",
"https://picsum.photos/id/1024/1920/1280",
__ob__: Observer]
it populates the dom but not rendered.
what am I missing??
If I face that situation then I check if I have created that property as reactive.
Means I have added v-model on it or not.
Other way is to add it in watch propery as shown below
watch:{
//just write name of the data propery and make it function
picutres(){}
//that's it
}
Now it will listen for the changes.
If you still somehow cannot fix that problem then other solution it to use custom events or a function
You will call function or trigger an event whenever you change your pictures array.
Then in function or event you can update your pictures array
I cannot for the life of me figure this out.
Fiddle at: https://jsfiddle.net/s8xvkt10/
I want
User clicks checkbox
Then based on separate conditions
Checkbox calculatedCheckedValue returns a data property /v-model of true/false
And the checked state reflects the calculatedCheckedValue
I can get:
The calculatedCheckedValue calculates and interpolates properly
But I fail at:
Having the :checked attribute render the calculatedCheckedValue properly in the DOM
e.g. If a false checkbox is clicked and the calculatedCheckedValue still returns false, the checkbox toggles onscreen between checked and unchecked
I’ve tried:
Using a v-model with a custom set that does the calculation and sets the local state which the custom get returns
Imitating a v-model using #change.prevent.stop="updateCalculatedValue" and :checked="calculatedValue"
Assuming the #change happens after the #click (which i think is wrong) and using #click.prevent.stop="updateCalculatedValue" and :checked="calculatedValue"
The model is working and rendering the calculated value as string in a DOM span,
but the checked value doesn't seem to respect the model value
Can someone please help me out?
I've solved the problem at: https://jsfiddle.net/pc7y2kwg/2/
As far as I can tell, the click event is triggered even by keyboard events (src)
And happens before the #change or #input events (src)
So you can click.prevent the event, but you need to either prevent it selectively or retrigger the event after the calculation.
//HTML Template
<input :checked="calculatedValue5" #click="correctAnswer" type="checkbox">
//VUE component
data() {
return {
calculatedValue5: false,
};
},
methods: {
correctAnswer(e){
const newDomValue = e.target.checked;
this.calculatedValue5 = this._calculateNewValue(newDomValue);
if(this.calculatedValue5 !== newDomValue){
e.preventDefault();
}
}
}
I think this is preventing checkbox value from updating before the data value, which seems to break the reactivity. I'm not sure the technical reason why, but the demo does work
I am creating a tab component that loads its v-tab-item components dynamically, given an array of configuration objects that consist of tabName, id, and tabContent which is a resource location for the component. I have it successfully loading the components. However, they don't actually initialize (or run their created() methods) until I switch tabs. I just get empty tabs with the correct labels. Using the DOM inspector initially shows just <componentId></componentId>, and then when I switch tabs, those tags are replaced with all of the component's content.
How do I get the dynamic components to initialize as soon as they are loaded?
EDIT: I created a CodePen here:
https://codepen.io/sgarfio/project/editor/DKgQON
But as this is my first CodePen, I haven't yet figured out how to reference other files in the project (i.e. what to set tabContent to so that require.js can load them up). I'm seeing "Access is denied" in the console, which makes it sound like it found the files but isn't allowed to access them, which is weird because all the files belong to the same project. So my CodePen doesn't even work as well as my actual project. But maybe it will help someone understand what I'm trying to do.
Also, after poking around a bit more, I found this:
http://michaelnthiessen.com/force-re-render/
that says I should change the key on the component and that will force the component to re-render. I also found this:
https://v2.vuejs.org/v2/guide/components-dynamic-async.html
Which has a pretty good example of what I'm trying to do, but it doesn't force the async component to initialize in the first place. That's what I need the async components to do - they don't initialize until I switch tabs. In fact they don't even show up in the network calls. Vue is simply generating a placeholder for them.
I got it working! What I ended up doing was to emit an event from the code that loads the async components to indicate that that component was loaded. The listener for that event keeps a count of how many components have been loaded (it already knows how many there should be), and as soon as it receives the right number of these events, it changes the value of this.active (v-model value for the v-tabs component, which indicates which tab is currently active) to "0". I tried this because as I noted before, the async components were loading/rendering whenever I switched tabs. I also have prev/next buttons to set this.active, and today I noticed that if I used the "next" button instead of clicking on a tab, it would load the async components but not advance the tab. I had already figured out how to emit an event from the loading code, so all I had to do at that point was capture the number of loaded components and then manipulate this.active.
I might try to update my CodePen to reflect this, and if I do I'll come back and comment accordingly. For now, here's a sample of what I ended up with. I'm still adding things to make it more robust (e.g. in case the configuration object contains a non-existent component URL), but this is the basic gist of it.
created: function() {
this.$on("componentLoaded", () => {
this.numTabsInitialized++;
if(this.numTabsInitialized == this.numTabs) {
// All tabs loaded; update active to force them to load
this.active = "0";
}
})
},
methods: {
loadComponent: function(config) {
var id = config.id;
var compPath = config.tabContent;
var self = this;
require([compPath], function(comp) {
Vue.component(id, comp);
self.$emit("componentLoaded");
});
}
}
I have a template in Vue.js that looks like this:
<div class="filter">
<div class="checkbox" v-for="(value, index) in range" :key="index">
<span class="hotels">{{ count(index) }}</span>
</div><!-- /.checkbox -->
</div><<!-- /.filter -->
The count method is important here. It triggers twice and also seems to be the cause of the second trigger and re-render.
This is my method:
count(value) {
console.log('count');
// Get the filtered AJAX data.
let hotels = this.allHotels;
const filters = Object.entries(this.filters);
for (let i = 0; i < filters.length; i += 1) {
// Get the Object from the array(index 0 being the name).
const filter = filters[i][1];
// Break the v-model reference by creating a shallow copy.
const values = filter.values.slice(0);
// Merge any selected checkbox values with the one we are currently iterating.
if (!values.includes(value)) values.push(Number(value));
// Check if the current filter has selected checkboxes and filter if it does.
hotels = filter.function(hotels, values);
}
return hotels.length;
}
Whenever I everything except the console.log() it works fine. Whenever I leave in the rest of the code the entire template seems to re-trigger. This seems strange because I am leaving the data in the template and the computed properties that the template relies on alone.
Is there any way to debug what is causing the second re-render?
Entire component:
https://gist.github.com/stephan-v/a5fd0b6bae854276666536da445bbf86
Edit
My components count function has a computed property in it called allHotels. This property is being set as a prop.
On the very first console.log it seems empty and then straight away it will get set causing the re-render. I was hoping that because this prop is coming from the backend it would take it as the initial value but this is not the case.
Is there anything to overcome this and prevent a re-render? There is no need for a re-render if Vue would take the prop data from the backend as initial data straight away.
Hopefully it is clear what I mean by this.
Replication:
Somehow I can't seem to replicate this, I would expect this to also work like my code and show an empty title on the first pass with a console.log:
https://jsfiddle.net/cckLd9te/123/
Perhaps because my prop data that I am passing into my component is a pretty big json_encoded block it takes time for Vue.js to interpret the data?