Difficulty arising from implementing v-if as a filter within a v-for loop in Vue.js

Question

Difficulty arising from implementing v-if as a filter within a v-for loop in Vue.js

I'm struggling a bit with setting up a conditional statement using v-if along with a loop using v-for in Vue. Here's what I have so far:

<div class="row form-group" v-for="(article, key, index) in articles" :key="key" v-if="article.pubdate(first four characters)">={{ filterYear}} >

I'm unsure of how to extract the first four characters from the pubdate and treat it as a number, as well as how to pass in the filterYear. The data structure for articles is JSON returned via Axios. However, the format of pubdate is: year, space, then month (e.g., 2007 Aug or 2009 Aug 1).

My goal is to isolate a year and use it within the v-if, displaying only articles written during or after that specific year. I also have similar functionality on the JavaScript side where values are identified and converted into a string (uid_string). Check out this example on CodePen.

javascript vue.js vuejs2

Answer 1

Answer №1

One way to simplify the loop filter instead of using a v-if condition is by utilizing a computed property. This method not only streamlines the template for the loop but also eliminates the need for extra calculations to determine the ordinal number for each item, as the index of the array can naturally serve as the ordinal number.

For instance, you can integrate the suggested filter from @Stephen into a computed property:

<script>
export default {
  computed: {
    filteredArticles() {
      const { articles, filterYear } = this
      return Object.values(articles)
        .filter(article => parseInt(article.pubdate.substring(0,4)) >= filterYear)
    }
  }
}
</script>

After defining the computed property, simply utilize it in your template like so:

<template>
  <div v-for="(article, index) in filteredArticles" :key="article.uid">
   ...
  </div>
</template>

To see a demonstration of this approach, check out this demo.

Answer 2

One way to simplify the loop filter instead of using a v-if condition is by utilizing a computed property. This method not only streamlines the template for the loop but also eliminates the need for extra calculations to determine the ordinal number for each item, as the index of the array can naturally serve as the ordinal number.

For instance, you can integrate the suggested filter from @Stephen into a computed property:

<script>
export default {
  computed: {
    filteredArticles() {
      const { articles, filterYear } = this
      return Object.values(articles)
        .filter(article => parseInt(article.pubdate.substring(0,4)) >= filterYear)
    }
  }
}
</script>

After defining the computed property, simply utilize it in your template like so:

<template>
  <div v-for="(article, index) in filteredArticles" :key="article.uid">
   ...
  </div>
</template>

To see a demonstration of this approach, check out this demo.

Answer 3

Answer №2

If you want to extract an integer year from the first four characters:

parseInt(article.pubdate.substring(0, 4))

<div  
v-for="(article, key, index) in articles" 
:key="key" 
v-if="parseInt(article.pubdate.substring(0, 4))>=filterYear">

Your code goes here... 
To display the article JSON, use curly braces: {{article}}.
Similarly for the date {{article.date}}, etc.
Avoid using curly braces within template attributes.

</div>

An advantage of Vue is that all template properties are relative to the component, eliminating the need to use this. as a reference.

To tidy up the template, consider moving the parseInt(...) and comparison logic to a component method.

You can see these changes in action on your updated codepen: https://codepen.io/anon/pen/NVrvre?editors=1111

Answer 4

If you want to extract an integer year from the first four characters:

parseInt(article.pubdate.substring(0, 4))

<div  
v-for="(article, key, index) in articles" 
:key="key" 
v-if="parseInt(article.pubdate.substring(0, 4))>=filterYear">

Your code goes here... 
To display the article JSON, use curly braces: {{article}}.
Similarly for the date {{article.date}}, etc.
Avoid using curly braces within template attributes.

</div>

An advantage of Vue is that all template properties are relative to the component, eliminating the need to use this. as a reference.

To tidy up the template, consider moving the parseInt(...) and comparison logic to a component method.

You can see these changes in action on your updated codepen: https://codepen.io/anon/pen/NVrvre?editors=1111

Difficulty arising from implementing v-if as a filter within a v-for loop in Vue.js

Answer №1

Answer №2

Similar questions

Having trouble accessing portlet resource URL from JavaScript in Liferay 6.2

Encountering a VUE error during unit testing operations

Enhance vue.js by adding your own custom filters

Is it possible to customize componentWillLeave(callback) in ReactCSSTransitionGroup?

Having trouble with rendering prop values in Vue.js?

Leverage the retrieved JSON data from the database within an HTML template using the Play

Node.js not resetting array properly

Utilizing jQuery AJAX to enable a functional back button feature upon modifying HTML

Exploring JSON without taking into account letter case

Upon initiating a React Native project, five critical vulnerabilities become apparent

What is the best way to ensure a function waits for a stable database connection before proceeding?

Create an array using modern ES6 imports syntax

Switching between rows in a table once information has been added to an array | Vue

Perform a JSON POST request from an HTML script to a Node.JS application hosted on a different domain

"Can you provide some guidance on transferring the selected row value to a button that is located outside the grid, including a parameter in v-data-table

Add a fading transition feature to images that are loaded at a later time

Error: Knockout sortable array failing to render nested elements accurately

Ways to ensure the synchronous execution of asynchronously invoked functions

Discover the process for breaking down JSON data into separate stages using the Express API

My browser is being overwhelmed by jQuery's each() function while trying to manipulate a large set of elements. How can I optimize my code to reduce the strain on my browser