How to conditionally display data in Vuejs - vuejs2

I have to display api returned data or No Data message. Below is my code in Vuejs:
<div v-if="resp.length > 0">
<div>data displayed here from api</data>
</div>
<div v-else>
No Data
</div>
Another approach I have tried:
<div v-show="resp.length > 0">
<div>data displayed here from api</data>
</div>
<div v-show="resp.length === 0">
No Data
</div>
Whether api returns data or not, "No Data" is getting displayed initially. If api returns data "No Data" disappears and actual data is shown. If no data from api, "No Data" stays.
Api data is getting loaded in beforeMount() lifecycle method. Any clue how to handle this? Appreciate your effort.

initially set default value false for isLoaded ,after the api data is loaded change the value of isLoaded to true
<div v-if="isLoaded">
<div v-if="resp.length > 0">
<div>data displayed here from api</data>
</div>
<div v-else>
No Data
</div>
</div>
<div v-else>
Loading
</div>

Related

Vue.js 3 and Modal with DaisyUI (Tailwind CSS)

I'm tinkering with DaisyUI within Vue.js 3 (porting an existing Vue+Bootstrap application to Tailwind CSS). I liked the idea that DaisyUI doesn't have JS wizardry going on behind the scenes, yet there seems to be some CSS voodoo magic that is doing things more complicated than they need to be (or at least this is my impression).
From the DaisyUI examples, here's the modal I'm trying to integrate:
<input type="checkbox" id="my-modal" class="modal-toggle"/>
<div class="modal">
<div class="modal-box">
<h3 class="font-bold text-lg">Congratulations random Internet user!</h3>
<p class="py-4">You've been selected for a chance to get one year of subscription to use Wikipedia for free!</p>
<div class="modal-action">
<label for="my-modal" class="btn">Yay!</label>
</div>
</div>
</div>
no javascript, yet the problem is that the modal will come and go according to some obscure logic under the hood that tests the value of the my-modal input checkbox at the top. That's not what I want. I want my modal to come and go based on my v-show="showModal" vue3 reactive logic!
Daisy doesn't seem to make that possible. Or at least not easily. What am I missing?
The modal is controller by the input field, so to open or close the modal just toggle the value of that input:
<template>
<!-- The button to open payment modal -->
<label class="btn" #click="openPaymentModal">open modal</label>
<!-- Put this part before </body> tag -->
<input type="checkbox" v-model="paymentModalInput" id="payment-modal" class="modal-toggle" />
<div class="modal modal-bottom sm:modal-middle">
<div class="modal-box">
<h3 class="font-bold text-lg">Congratulations random Internet user!</h3>
<p class="py-4">You've been selected for a chance to get one year of subscription to use Wikipedia for free!</p>
<div class="modal-action">
<label class="btn" #click="closePaymentModal">Yay!</label>
</div>
</div>
</div>
</template>
<script lang="ts" setup>
const paymentModalInput = ref()
const openPaymentModal = () => {
paymentModalInput.value = true
}
const closePaymentModal = () => {
paymentModalInput.value = false
}
</script>

Vue.js: Loading template (or div) when user clicks button?

So I currently have a template sitting in a ".vue" file like so:
<template>
<div id="dataAttachToMe"></div>
</template>
I don't want this to load, unless a user clicks a button, something like
<button #click="loadTheTemplateAbove">See Data</button>
I've tried using this example:https://v2.vuejs.org/v2/guide/conditional.html#Controlling-Reusable-Elements-with-key. But it says something like "Component template should contain exactly one root element" in the error message.
I need more than a show/hide here I think, something that can initiate the template dynamically.
<template>
<div id="data">
<button #click="loadTemplate">Load the template</button>
<div v-if="buttonClicked">
<div id="dataAttachedToThisDiv"></div>
</div>
</div>
</template>
The error you are getting, means that there is more than one root element inside <template></template> tag.
It is required in Vue.js (and other template based frameworks/libraries) to have only one root element.
This will NOT work:
<template>
<div id="dataAttachToMe"></div>
<button #click="loadTheTemplateAbove">See Data</button>
</template>
This will work:
<template>
<div id="someRootDiv">
<div id="dataAttachToMe">Some data</div>
<button #click="loadTheTemplateAbove">See Data</button>
</div>
</template>
Here is a code example (App.vue) of what you are trying to achieve:
Basic idea: we have to create a variable, that will be changed upon button click. We add v-if directive that depends on that variable and will handle element's visibility.
Welcome to StackOverflow. When you get the error Component template should contain exactly one root element it means that you can only have one root element in your template. You can fix that error by wrapping everything in a blank div like so
<template>
<div>
<template v-if="loginType === 'username'">
<label>Username</label>
<input placeholder="Enter your username">
</template>
<template v-else>
<label>Email</label>
<input placeholder="Enter your email address">
</template>
</div>
</template>
Please edit your post and place you <script> tag. Conditional Rendering requires a data field of a boolean that you can place in your if statement on your template
<template>
<div>
<div v-if="show">{{message}}</div>
<div v-if="#show">Not Showing when show is set to false</div>
<button v-on:click="show = true">Show</button>
</div>
</template>
<script>
module.exports {
data: function () {
message: 'Hello Vue!',
show: false
}
}
</script>

Modal memory leak as more modals added

I am developing an Angular 4 application using ngx-bootstrap modals heavily. I am currently using the template + modalService way of opening up modals. During a click event, this line of code is called:
#ViewChild() worklistTemplate;
// ...
this.modalRef = this.modalService.show(this.worklistTemplate, this.config);
And the worklist template looks like this:
<ng-template #worklistTemplate>
<app-action-view
[leftButtons]="leftButtons"
[labelHeader]="modalHeader"
[labelIcon]="modalIcon"
[modalRef]="modalRef">
<div class="row modal-info-panel">
<div class="col-xs-4 modal-user-info">
<fa name="mars" class="gender-icon"></fa>
<div class="field-panel">
<input type="text"
[ngModel]="rowInfo.lastName"
[ngClass]="{ 'modal-editable-field': modalFieldsEditable }"
[disabled]="!modalFieldsEditable">
<input type="text"
[ngModel]="rowInfo.firstName"
[ngClass]="{ 'modal-editable-field': modalFieldsEditable }"
[disabled]="!modalFieldsEditable">
<div>
<label for="modal-mrn">MRN --</label>
<input id="modal-mrn" type="text"
[ngModel]="rowInfo.mrn"
[ngClass]="{ 'modal-editable-field': modalFieldsEditable }"
[disabled]="!modalFieldsEditable">
</div>
<div>
<label for="modal-dob">DOB --</label>
<input id="modal-dob" type="text"
[ngModel]="rowInfo.birthDate"
[ngClass]="{ 'modal-editable-field': modalFieldsEditable }"
[disabled]="!modalFieldsEditable">
</div>
<div class="edit-panel">
<fa *ngIf=modalFieldsEditable class="worklist-edit-buttons green-hover link" name="floppy-o" tooltip="Save" (click)=saveChanges()></fa>
<fa *ngIf=modalFieldsEditable class="worklist-edit-buttons red-hover link" name="times" tooltip="Cancel" (click)=toggleModalFields()></fa>
</div>
</div>
</div>
<div class="col-xs-8 modal-id-info">
Associated ID
<div class="full-width">
<div class="row" *ngFor="let i of rowInfo.associatedIDs">
<div class="col-xs-6 cell">{{i.id}}</div><div class="col-xs-6 cell">{{i.source}}</div>
</div>
</div>
</div>
</div>
<div class="row" id="modal-table">
<app-table-view
[columns]="objDetailsCols"
[tableData]="objDetailsData"
[expandTemplate]="rowImageContainer"
[expandColStyle]="expandColStyle">
</app-table-view>
</div>
<div *ngIf="resolvePanelVisible" class="resolve-panel"
[#slideRight]>
<div class="resolve-label">
<fa class="lt-icon" name="wrench"></fa>
Resolve QA Issue
</div>
<div class="resolve-body">
Hello, World!
</div>
<div class="resolve-footer">
<a>Validate</a>
<a>Resolve</a>
<a>Reload</a>
<a (click)="toggleResolvePanel()">Close</a>
</div>
</div>
</app-action-view>
</ng-template>
The modal can be closed by clicking outside of the modal boundaries or there is a button inside the ActionViewComponent that calls modalRef.hide().
Memory usage increases drastically as more and more modals are opened. In fact, if I open the modal around 5 times, the application becomes sluggish and almost unusable. This is especially apparent if there are many rows in our TableViewComponent.
Is there a problem with the way I am using the modals, or is this an issue related to ngx-bootstrap modals? OR, is the issue related to the browser and unavoidable? I am developing on Chrome 62 right now.
I have verified that onDestroy is never called on the TableViewComponent inside the modal. It is not even called if I navigate to a different page component, though another table (not in the template) does have onDestroy called when navigating from the page.
Any feedback is appreciated greatly- I have been stuck for way too long on this.
This is an issue of ngx-bootstrap, unfortunately. I created a pull request (https://github.com/valor-software/ngx-bootstrap/pull/3179) so this will be fixed as soon as my PR is merged and new version is released.

preventing Vue from aggresively reusing dom-elements

Condider the following snippet:
<template v-if="tryIsMobile" >
<div class='device device-mobile-portrait' :class="deviceClass">
<div class="device-scroller-container">
<div class='device-scroller'>
<img id='tryit-img-mobile' :src="srcUrlMobile" v-on:load="onImgLoad" v-on:error="onImgError"/>
</div>
</div>
</div>
</template>
<template v-else>
<div class='device device-tablet-landscape' :class="deviceClass" >
<div class="device-scroller-container">
<div class='device-scroller'>
<img id='tryit-img-tablet' :src="srcUrlTablet" v-on:load="onImgLoad" v-on:error="onImgError"/>
</div>
</div>
</div>
</template>
This code conditionally renders one of the two images. Some user action results in the actual shown image to be toggled.
What I'm seeing is the following: When toggling from say, tryit-img-mobile to tryit-img-tablet, the image loaded as part of tryit-img-mobile will get displayed with different dimensions instantly. However, during the time the image loads it's new source :src="srcUrlTablet", the image with src :src="srcUrlMobile" still displays.
This is probably due to Vue using the same img-tag for both the templates. How can I prevent Vue from doing this, and instead use seperate img-tags?
In cases such as this, Vue uses a special key attribute that tells it not to reuse the same element. Give each element this attribute with a unique value, and Vue will no longer reuse the same element:
<div v-if="tryIsMobile"
class="device device-mobile-portrait"
:class="deviceClass"
key="mobile"
>
...
</div>
<div v-else
class="device device-tablet-landscape"
:class="deviceClass"
key="tablet"
>
...
</div>

Dijit: Why am I getting an "Uncaught Error: Invalid Template"?

I have a dijit that looks fine as far as I can tell, but it is raising Uncaught Error: Invalid template every time. I have not been able to figure out why. All variables (e.g. ${variableName} are defined in the widget correctly.
Here is the widget:
<div class="${classPrefix}-wrapper">
<div class="${classPrefix} flair" dojoAttachPoint="flairNode"></div>
<div class="${classPrefix}-count hidden" dojoAttachPoint="countWrapperNode">
<div class="count" dojoAttachPoint="countNode">0</div>
</div>
<div class="${classPrefix} ${secondaryClass} action hidden" dojoAttachPoint="secondaryClickNode" dojoAttachEvent="onclick:_onSecondaryClick">
<div class="${classPrefix}-inner"></div>
<div class="${classPrefix}-icon"></div>
</div>
<div class="${classPrefix} ${primaryClass} action" dojoAttachPoint="primaryClickNode" dojoAttachEvent="onclick:_onPrimaryClick">
<div class="${classPrefix}-inner"></div>
<div class="${classPrefix}-icon"></div>
</div>
<div class="${classPrefix}-message hidden" dojoAttachPoint="messageNode"></div>
</div>
<div class="${actionPromptNodeClass}" dojoAttachPoint="actionPromptMessageNode">
<span dojoAttachPoint="actionPromptMessage">${actionPromptText}</span>
<span dojoAttachPoint="actionCompletedMessage" class="hidden">${actionCompletedText</span>
</div>
Found the answer to my question. It turns out that you can only have one root node in a Dijit. I missed this in the docs, but it is at the bottom of this tutorial:
Common Pitfalls
Be sure to only have one root node in your template
Don’t start or end your template with a comment because that means you technically have two nodes
Avoid a trailing </div> at the end of your template
There may be only one root element in the template. Wrap your template into <div></div> and it should work.