I have an HTML element like below
<div v-if="showOriginalContent"> original content</div>
<div v-else> default content </div>
initial value of showOriginalContent is false
and from mounted method am calling an another method where i will make the value of showOriginalContent to true based on some conditions . Currently even if the showOriginalContent is true i can see that v-else is getting displayed for a fraction of seconds before v-if is rendered in the DOM . How can i solve this issue ? I tried to move the function call to all other life cycle methods but nothing is working . I have gone through before and after navigation approach in vue js ,Is it possible to apply that logic here?
I think it's normal if I understood correctly what you posed as the problem.
Because the mounted state is called when the view has already been OK and displayed and only once.
So a variable declaring in this method its change will not necessarily have an effect on what should be displayed.
Try to see the lifecycle in Vuejs for more detail.
Put it in computed or watch methods to see.
Use an outer div and control this div with another variable that will be true when you are done with your condition parts in mounted hook.. like this..
<div v-if="conditioncheckdone">
<div v-if="showOriginalContent"> original content</div>
<div v-else> default content </div>
</div>
It will resolve your issue of displaying v-else stuff while you are checking your conditions in mounted
turn the default showOriginalContent value to null instead of false
Related
I have tried / guessed at every combination of v-bind/v-model/:checked/:value I can think of, but I can't get these damn checkboxes checked on load:
Using Vue Material / Vue3:
<div v-if="items.length">
<div
v-for="(value,key,index) in this.items"
:key="index"
:ref="'icon'+items[key].id">
<md-checkbox
:id="'TDS'+key"
v-model="items[key].complete"
true-value="1"
#change="doDo(items[key].id)"
class="md-primary m-0"
>
{{ items[key].item }} {{items[key].complete}}
</md-checkbox>
</div>
</div>
The bit I can't figure out is how to make the checkbox checked if items[key].complete=1 when data is loaded.
You are already inside the loop
v-model="value.complete"
Same goes for all other bindings.
And your data should not be accessed with this in your template
v-for="(value,key,index) in items"
This one should already work, if you receive your data properly, it may update itself due to reactivity. Maybe try v-model="!!items[key].complete" just to be sure that your value is coerced to a Boolean.
I'm using a UIKit library for a tab component that listens to a uk-tab property that targets an id. The problem with this, is that it creates the same ID for every tabbed component. I like the UI, but whoever thought of this, didn't think too far into it. I could fix it by making the id dynamic but I am having trouble calling it in the uk-tab property because it is rendering a string. Coming from a react background, I would do a string literal and some JSX, something like #item-${_id}to show #item-12, #item-13....and so on. But That's not working. How can I do this in Vue?
Here is an example of how it works
<div class="mytrigger">
<ul uk-tab="connect: #component-tab-left; animation: uk-animation-fade">
</div>
<div class="mytargetedtab">
<ul id="component-tab-left" class="uk-switcher">
</div>
Here is an example of how what I need
<div class="mytrigger">
<ul uk-tab="connect: #_uid+'switcher'; animation: uk-animation-fade">
</div>
<div class="mytargetedtab">
<ul :id="_uid+'switcher'" class="uk-switcher">
</div>
Check out the dev tools. It should be 810switcher, but instead is taking it as a string
Any ideas? Thanks
I believe what you need is:
<ul :uk-tab="`connect: #${_uid}switcher; animation: uk-animation-fade`">
Or if you prefer not to use backticks:
<ul :uk-tab="'connect: #' + _uid + 'switcher; animation: uk-animation-fade'">
The output will be:
<ul uk-tab="connect: #22switcher; animation: uk-animation-fade">
A few notes:
Using a : is short for v-bind: but don't let the name confuse you. v-bind doesn't necessarily bind anything, it just makes the attribute value a JavaScript expression.
I'd avoid using numbers at the start of element ids, I've seen that cause problems in the past. It'd be better to put the numbers at the end.
The underscore at the start of _uid indicates that it's private to Vue. There are no guarantees about what form it will take or whether it will even exist going forward.
Use data-uk-tab instead of uk-tab like below.
<div class="mytrigger">
<ul data-uk-tab="{connect: `#${_uid}switcher`, animation: 'uk-animation-fade'}">
</div>
<div class="mytargetedtab">
<ul :id="_uid+'switcher'" class="uk-switcher">
</div>
For more information => Switcher with tabs
You can use any javascript expression in a data binding in vue. So, if you bind a string template to the attribute, it'll populate what you expect.
<ul :uk-tab="`connect: #${uid}switcher`'; animation: uk-animation-fade">
I have a primeng (angular 2) dialog with a dropdown. I want to set focus to the dropdown when the dialog shows. The problem appears to be that my div is rendered conditionally.
My code:
<p-dialog (onShow)="fe.applyFocus()">
<div *ngIf="selectedItem">
<button pButton type="button" (click)="fe.applyFocus()" label="Focus"></button>
<p-dropdown #fe id="reason" [options]="reasonSelects" [(ngModel)]="selectedReason" ></p-dropdown>
</div>
</p-dialog>
In this code the button works fine, but the onShow() (outside the *ngIf div) tells me fe is undefined.
How can I access the local variable inside the *ngIf?
Yes, this is a real pain. Unfortunately, due to the way *ngIf works, it completely encapsulates everything inside (including the tag it's on).
This means anything declared on, or inside, the tag with the ngIf will not be "visible" outside of the ngIf.
And you can't even simply put a #ViewChild in the ts, because on first run it might not be present... So there are 2 known solutions to this problem...
a) You can use #ViewChildren. This will give you a QueryList that you can subscribe to, which will fire off every time the tempalte variable changes (ie. the ngIf turns on or off).
(html template)
<div>{{thing.stuff}}</div>
<my-component #thing></my-component>
(ts code)
#ViewChildren('thing') thingQ: QueryList<MyComponent>;
thing: MyComponent;
ngAfterViewInit() {
this.doChanges();
this.thingQ.changes.subscribe(() => { this.doChanges(); });
}
doChanges() {
this.thing = this.thingQ.first;
}
b) You can use #ViewChild with a setter. This will fire the setter every time the ngIf changes.
(html template)
<div>{{thing.stuff}}</div>
<my-component #thing></my-component>
(ts code)
#ViewChild('thing') set SetThing(e: MyComponent) {
this.thing = e;
}
thing: MyComponent;
Both of these examples should give you a "thing" variable you can now use in your template, outside of the ngIf. You may want to give the ts variable a different name to the template (#) variable, in case there are clashes.
You can separate the use of template on NgIf level:
<ng-container *ngIf="selectedItem; else elseTemplate">
<p-dialog (onShow)="fe.applyFocus()">
<div>
<button pButton type="button" (click)="fe.applyFocus()" label="Focus"></button>
<p-dropdown #fe id="reason" [options]="reasonSelects" [(ngModel)]="selectedReason"></p-dropdown>
</div>
</p-dialog>
</ng-container>
<ng-template #elseTemplate>
<p-dialog>
</p-dialog>
</ng-template>
I have a template with several divs, each containing an #click that triggers a specific function and a corresponding visual effect
<template>
<div #click="function doThis(param1)></div>
<div #click="function doThis(param2)></div>
<div #click="function doThis(param3)></div>
<div #click="function doThis(param4)></div>
<div #click="function doThis(param5)></div>
</template>
method: {
doThis(param) {
lightUpDiv(corresponding param)
}
}
I'm also calling doThis from the parent via a $broadcast. What if any, is the best Vueish way to trigger the corresponding lightUpDiv call from the $broadcast? (just use getElementById and .click()???). I used individual divs vs a v-for in the hope that this is easier.
I should note that there are several instances of the template On the page. Even if the same visual effect is caused simultaneously on all the templates that is fine. If there is a way to call them on the specific template instances that is even better.
I've spent hours trying to figure this out and cannot seem to do it. Have read all the guide and API. I know there is some way to bind the data to make the template instances unique but can't seem to get it. Definitely couldn't see the #click from $broadcast solution
Thanks for any help!!
<div #click="doThis"></div>
OR
<div #click="doThis($event)"></div>
Both are functionally equivalent, but second version is recommended as it is more explicit.
In javascript,
doThis: function(ev){
//ev is event object and ev.target refers to the div you need.
alert(ev.target.innerHTML);
}
Demo
Event object details
Given the following:
<div id="#my-container">
<div class="title">Companies</div>
<div class="tab active tab-apple">Apple</div>
<div class="tab tab-google">Google</div>
</div>
When page is loaded without any tab clicks yet, whichever tab with the default active class, needs to go in the .title div. For the example above, <div class="title">Apple</div>
On click of a tab, the class is switched to active, and vue.js needs to update the .title div once again.
How can this be done with vue.js? I've tried but not able to get it to work as intended.
The answer by David is one way to do it. But Vuejs offers in-line computations for this. So, no need to hook into any CSS event. Here's some code to explain:
Create a data property active_tab, just like David mentioned. And then bind it's value just like he's done it. In your tabs, add an click event and at that event, assign appropriate value to active_tab.
<div class="tab active tab-apple" #click="active_tab = Apple">Apple</div>
<div class="tab tab-google" #click="active_tab = Google">Google</div>
Now, to dynamically assign the active class to the respective tab, make the class attribute, a computed property, like this:
<div
:class="['tab', active_tab == 'Apple' ? 'active' : '', 'tab-apple']"
>
Apple
</div>
What this code is basically doing is, :class makes class a computed property. Then the commas in the array divide the statement. So, the computation will always add tab and tab-apple classes. But, only if active_tab == 'Apple' then ? add 'active' else : add ''
Not sure which CSS framework you are using, but normally I hook into the events thrown by the tab switching (many CSS frameworks provide this access). Once hooked into it, you can write a Vue custom directive that will take that event and use it to update a VM attribute that indicates which tab is active.
Then you can use normal mustache templating to get it into your template:
<div class="title">{{ active_tab }}</div>