Vuejs undefined object inside a watched property

Question

I am having an issue with watched property in Vuejs. The error i am getting - Cannot read property 'list' of undefined even though the list is defined. I am getting the error after it does the if check (at the var index .... line).

watch: {
   selectedRole: () => {
     if (this.modifiedUser.list) {
        var index = this.modifiedUser.list.findIndex(obj => obj.id == 
               this.selectedObj);
        this.modifiedUser.list[index].object = Object.assign({}, this.selectedObj);
  }
}

Any idea why it passes the check in the if statement but fails on the next line?

VueJs - v2.5.2.

The error doesn't mean `list` is undefined but `modifiedUser` is. — RobDil, Feb 21 '18 at 13:07
Can you try `if (this.modifiedUser && this.modifiedUser.list)` as your condition? — m3characters, Feb 21 '18 at 13:07
@MicaelNussbaumer I did, now it still get into the if statement but the `var index` variable is undefined. — Fima Taf, Feb 21 '18 at 13:39
take the `var index` out of the if statement, and give it a default value above it. Then update it in the if statement, if the if-statement is true — Jeffrey, Feb 21 '18 at 13:40

score 0 · Answer 1 · answered Feb 21 '18 at 13:57

0

In if (this.modifiedUser.list) { try check if modifiedUser is undefined, please.

Check also if index isn't undefined after:

var index = this.modifiedUser.list.findIndex(obj => obj.id == this.selectedObj);

Hope this helps

answered Feb 21 '18 at 13:57

Luiz Antônio da Silva Júnior

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The modified user is defined, but the check fails. – Fima Taf Feb 21 '18 at 15:48

Vuejs undefined object inside a watched property

1 Answers1