Develop Reference

Conditionally hide the nth element of a v-for loop without modifying the array. vue 3 composition api search function

I have a ref variable (foxArticles ), which holds a list that contains 100 items. In a v-for loop i loop over each value. As a result, i have 100 values rendered on the page.
<template>
<div class="news_container">
<div
v-for="article in foxArticles"
v-bind:key="article"
class="article_single_cell"
>
<div
class="news_box shadow hover:bg-red-100 "
v-if="containsKeyword(article, keywordInput)"
>
<div class="news_box_right">
<div class="news_headline text-red-500">
<a :href="article.url" target="_blank">
{{ article.title }}
</a>
</div>
</div>
</div>
</div>
</div>
</template>
<script>
const foxArticles = ref([]);
</script>
I also have a search function, which returns the value, if it includes the passed in keyword. The function is used in the child of the v-for loop.
<div class="search_input_container">
<input
type="text"
class="search_input"
v-model="keywordInput"
/>
</div>
<script>
const keywordInput = ref("");
function containsKeyword(article, keywordInput) {
if (article.title.toLowerCase().includes(keywordInput.toLowerCase())) {
return article;
}
}
</script>
The problem is, i can't use .slice() on the foxArticles array in the v-for loop, because that screws up the search functionality, as it returns only the values from the sliced range.
How can i have the access the all of the values of the array, while not rendering all 100 of returned articles on the initial load?
Any suggestions?

I think your approach will make it incredibly complex to achieve. It would be simpler to always iterate over some set, this set is either filtered based on a search-term, or it will be the first 100 items.
I'm not very familiar yet with the Vue 3 composition api so I'll demonstrate with a regular (vue 2) component.
<template>
<div class="news_container">
<div
v-for="article in matchingArticles"
v-bind:key="article"
class="article_single_cell"
>
... news_box ...
</div>
</div>
</template>
<script>
export default {
...
computed: {
matchingArticles() {
var articles = this.foxArticles;
if (this.keywordInput) {
articles = articles.filter(article => {
return this.containsKeyword(article, this.keywordInput)
})
} else {
// we will limit the result to 100
articles = articles.slice(0, 100);
}
// you may want to always limit results to 100
// but i'll leave that up to you.
return articles;
}
},
....
}
</script>
Another benefit is that the template does not need to worry about filtering results.

ok, so i kind of came up with another solution, for which you don't have to change the script part...
instead of having one v-for loop , you can make two of them, where each one is wrapped in a v-if statement div
The first v-if statement says, If the client has not used the search (keywordInput == ''), display articles in the range of (index, index)
The second one says = If the user has written something (keywordInput != ''), return those articles.
<template>
<div class="news_container">
<!-- if no search has been done -->
<div v-if="keywordInput == ''">
<div
v-for="article in foxArticles.slice(0, 4)"
v-bind:key="article"
class="article_single_cell"
>
<div class="news_box shadow hover:bg-red-100 ">
<div class="news_box_right">
<div class="news_headline text-red-500">
<a :href="article.url" target="_blank">
{{ article.title }}
</a>
</div>
</div>
</div>
</div>
</div>
<!-- if searched something -->
<div v-else-if="keywordInput != ''">
<div
v-for="article in foxArticles"
v-bind:key="article"
class="article_single_cell"
>
<div
class="news_box shadow hover:bg-red-100 "
v-if="containsKeyword(article, keywordInput) && keywordInput != ''"
>
<div class="news_box_right">
<div class="news_headline text-red-500">
<a :href="article.url" target="_blank">
{{ article.title }}
</a>
</div>
</div>
</div>
</div>
</div>
</div>
</template>
im not sure how this impacts performance tho, but that's a problem for another day

How to loop through unknow number of nested json object in Angular with ngFor?

I'm trying to display all the reply from this json :
https://www.reddit.com/r/AskReddit/comments/k8w43d/people_with_the_last_name_pepper_who_have.json
So, depending of the post im loading and the reply, my number of children will differ. How can I loop throught it until I reach the last reply with children (body[2].data.children) ?
Like this :
<div class="replies-box" *ngFor="let reply of comments.body[1].data.children">
<div class="reply-header">
<p class="reply-author"><b>From</b> : {{ reply.data.author }}</p>
<p class="reply-send"><b>Send</b> : {{ this.getDateReply(reply.data.created_utc) }}</p>
</div>
<div class="text-first-reply" [innerHTML]="this.getHtmlDecode(reply.data.body_html)">
</div>
</div>
I have only the first level of reply, is there a way to simply loop through them all ?
Thanks in advance.

I would use a recursion type of approach.
Develop a app-comment component and if comment has children, loop over the children and display the app-comment. That way it will loop over the comments until no more children
<div *ngIf='comment'>
<span *ngIf='comment.kind; else showComment'>Kind: {{ comment.kind }}</span>
<ng-template #showComment>
<span>{{ comment }}</span>
</ng-template>
<div>
<app-comment *ngFor='let child of comment.data?.children' [comment]='child'> </app-comment>
</div>
</div>
See this sample illustration

Simply use ngFor inside ngFor with help of ng-container (will not create extra dom elements)
<div class="replies-box">
<ng-container *ngFor="let commentBody of comments.body">
<ng-container *ngFor="let reply of commentBody.data.children">
<div class="reply-header">
<p class="reply-author">
<b>From</b> : {{ reply.data.author }}
</p>
<p class="reply-send">
<b>Send</b> : {{ this.getDateReply(reply.data.created_utc) }}
</p>
</div>
<div class="text-first-reply" [innerHTML]="this.getHtmlDecode(reply.data.body_html)">
</div>
</ng-container>
</ng-container>
</div>

how to add :key in v-for with multiple divs

I want to make v-for loop without any html element so I decided to use <template as parent. I don't know to assign :key for this loop. I can't assign it to template and to every div inside loop. Any ideas?
<template
v-for="{ id, text, option, percentage, value } in reports"
>
<div class="table-row__index">
{{ id }}
</div>
<div class="table-row__title">
<p>{{ text }} - <strong>{{ option }}</strong></p>
</div>
<div class="table-row__info">
{{ percentage }}%
</div>
<div class="table-row__info">
{{ value }}
</div>
</template>

As a good practice we should always have a parent element inside. But due to your constraints, it's okay to use for loop on template as given in official docs
https://v2.vuejs.org/v2/guide/list.html#v-for-on-a-lt-template-gt
In this case, any keys have to be added to child elements/components and this is what officially recommended.
See this example and please add keys to your div's inside template.
new Vue({
el: '#app'
})
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
<template v-for="n in 5">
<span :key="'number' + n">{{ n }}</span>
<span :key="'dot' + n">. </span>
</template>
</div>

you just can't have the for loop in your template. The for loop directive is only allowed to be inside the first child component ( or root component) inside your template.
Here is an example of how you can render your loop:
<template>
<div class="cant-have-for-loop-this-is-the-root-component">
<div v-for="{ id, text, option, percentage, value } in reports" :key="{id}">
<div class="table-row__index">
{{ id }}
</div>
<div class="table-row__title">
<p> {{ text }} - <strong>{{ option }}</strong></p>
</div>
<div class="table-row__info">
{{ percentage }}%
</div>
<div class="table-row__info">
{{ value }}
</div>
</div>
</div>
</template>
This runs soomthly, and with no hesitations. And renders with no styling as this screenshots depicts:
Hope this answers what you want to achieve.

ng-click to affect only the element it is inside

I am using ng-repeat to generate some elements...
<div class="form-block" ng-repeat="form in formblock | filter:dateFilter">
<div ng-click="showResults()" ng-if="repeat == true" class="drop">{{ form.form_name }} <span class="caret"></span></div>
<div ng-show="results" class="formURL">{{ form.url }}</div>
<div ng-show="results" class="formCount">{{ form.count }}</div>
<div ng-show="results" class="formSubmit">{{ form.submit }}</div>
</div>
As you can see, ng-click="showResults()" toggles the display of the other elements. The problem is, I only want the ng-click to toggle the elements inside the same container, not toggle all elements.
In short, I only want the click event to affect the elements in the same container that the function is called, how can I do this?
this is showResults in my controller...
$scope.showResults = function(){
return ($scope.results ? $scope.results=false : $scope.results=true)
}

ng-repeat provides you with a special variable (unless you already have an identfier): $index.
Using this, you can store (instead of a single boolean value) an object $index => toggleState in your angular code:
$scope.hiddenHeroes = {};
$scope.toggleHero = function (idx) {
$scope.hiddenHeroes[idx] = !$scope.hiddenHeroes[idx];
}
And in your HTML:
<div ng-repeat="hero in heroes">
<div class="hero" ng-hide="hiddenHeroes[$index]">
<h1>
{{hero}}
</h1>
All you want to know about {{hero}}!
<br />
</div>
<a ng-click="toggleHero($index)">Toggle {{hero}}</a>
</div>
See it live on jsfiddle.net!

You can use $index to index item/containers and show the corresponding results:
<div ng-click="showResults($index)" ng-if="repeat == true" class="drop">{{ form.form_name }} <span class="caret"></span></div>
<div ng-show="results[$index]" class="formURL">{{ form.url }}</div>
<div ng-show="results[$index]" class="formCount">{{ form.count }}</div>
<div ng-show="results[$index]" class="formSubmit">{{ form.submit }}</div>
And your function
$scope.showResults = function(index){
return ($scope.results[index] ? $scope.results[index]=false : $scope.results[index]=true)
}

Assign value to dynamically created scope variables

I'm trying to create a means to toggle dynamically created rows of information. I've tried using ng-init, and then passing it to a function, but I'm screwing up somewhere and I can't seem to wrap my head around how or if this is possible. The gap, I believe, is in getting the concatenated scope variable to be referenced elsewhere. I'm using Bootstrap 3 and AngularJS 1.5.
The HTML:
<div class="row" data-ng-repeat="equipment in task.equipment">
<div class="col-md-12">
<h4 class="green-text">
{{ equipment.equipId }}
<small class="green-text">
<i class="glyphicon"
data-ng-class="{'glyphicon-triangle-bottom': field{{ $index }}, 'glyphicon-triangle-right': !field{{ $index }}}"
data-ng-init="equipment['field' + $index] = true"
data-ng-click="toggleTaskEquip('field{{ $index }}')">
field{{ $index }}: I WANT THIS TO WORK</i>
</small>
</h4>
</div>
<div data-ng-show="field{{ $index }}">
...stuff here...
</div>
</div>
The JS:
$scope.toggleTaskEquip = function(toggleBool)
{
if (toggleBool === true)
$scope.isTaskEquipOpen = false;
else if (toggleBool === false)
$scope.isTaskEquipOpen = true;
};

If I understand the problem correctly, you want to be able to toggle the boolean created in the ng-init with a click.
I think you need this:
<div class="container-fluid">
<div ng-controller="MyCtrl">
<div class="row" data-ng-repeat="equipment in task.equipment">
<div class="col-md-12">
<h4 class="green-text">
{{equipment.equipId}}
<small class="green-text">
<i class="glyphicon"
data-ng-class="{'glyphicon-triangle-bottom': isVisible, 'glyphicon-triangle-right': !isVisible}"
data-ng-init="isVisible = true"
data-ng-click="isVisible = !isVisible">I WANT THIS TO WORK</i>
</small>
</h4>
</div>
<div data-ng-show="isVisible">
...stuff here...
</div>
</div>
</div>
</div>
You don't even need the function toggleTaskEquip on the $scope.
JSFiddle here.
ng-repeat creates a new scope for each template instance, so you can just create a separate isVisible for each equipment with isVisible = true in the ng-init.