Vue Computed Property not updating; Troubleshooting Steps

Vue.js is a very popular JavaScript library that is known for its reactivity, flexibility, and intuitive API. However, reactivity and flexibility come with some drawbacks, leading to the developer’s performance or a headache. The computed property is a very famous and most known feature of Vue.js, which is used to update some variable or perform some calculation depending upon some other variable’s updation.

This post will try to troubleshoot the problems that occurred when the computed property does not work or update what we want. Let’s have a look at the scenarios, what might go wrong, and Vue Computed Property not updating.

Scenario # 1:

First of all, make sure you did not make any logical error like implementing the wrong logic. To avoid the possible logical errors, check the following things:

• Verify that variable names are correct.
• You are taking care of the scopes of the variable using “this”.

Scenario # 2:

The second thing you might have mistaken in the computed property is that you are not caring about the Computed property’s side effects like editing some data inside a computed property or calling other functions. For example, reversing the array within a computed property.

Suppose we have an array in our component.

  data(){
    return{
      arrVar:[1,2,3]
    }
  },

In the computed property, we are reversing the array.

  computed:{
    arrayReverse(){
      return this.arrVar.reverse();
    }
  }

But, when we run the project, it will show an error of ‘Unexpected side effect in “arrayReverse” computed property.’ because it will always do the same task again and again and reverse the original array every time.

So, try to avoid data manipulation in the computed property, and it will work perfectly fine for you.

Scenario # 3:

Another scenario could be that the computed property is stuck in an infinite loop, and it keeps on re-computing something. Since computed property watches every variable included in the computed property and reacts or gets recomputed on the change of any variable involved in this property, if you change the state of any variable inside the computed property, the computed property detects the change. It starts to re-compute itself, and it won’t be able to get out of this infinite loop.

These are some of the possible ways which could lead to the computed property not updating problem.

Conclusion

This post has gone through the most common scenarios the developers faced for Vue Computed property not updating and provided profound and to-the-point troubleshooting steps for each scenario. If you still have not found your solution yet, feel free to ask your questions on the Vue community platforms and get your questions answered within no time.

from Linux Hint https://ift.tt/3c8Yg2A