# Computed property does not update when nested dependent property changes if computed setter is called

**URL:** <https://discuss.emberjs.com/t/computed-property-does-not-update-when-nested-dependent-property-changes-if-computed-setter-is-called/17123>\
**Category:** Questions\
**Created:** [October 14, 2019, 2:44pm UTC](https://discuss.emberjs.com/t/computed-property-does-not-update-when-nested-dependent-property-changes-if-computed-setter-is-called/17123 "2019-10-14T14:44:48Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Akash\_D\_Souza](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.emberjs.com/akash_d_souza/32/12939_2.png) [@Akash\_D\_Souza](https://discuss.emberjs.com/u/Akash_D_Souza)\
**Post date:** [October 14, 2019, 2:44pm UTC](https://discuss.emberjs.com/t/computed-property-does-not-update-when-nested-dependent-property-changes-if-computed-setter-is-called/17123/1 "2019-10-14T14:44:48Z")

</div>

Twiddle: [Ember Twiddle](https://ember-twiddle.com/706dc2003c71ffee87e85a87f467b1ef?numColumns=2&openFiles=controllers.application.js%2Ctemplates.application.hbs)

I have a computed property (`comp2`) which depends on another computed property(`comp1`) which depends on a property, `foo`, in the controller. I also have another property `valueOfComp2` in the controller which, for the sake of simplicity, is updated with the value of `comp2` through `update` method

During `init`, I set `comp2` to some value. After this, any update to `foo` will not reflect in `comp2` or `valueOfComp2`

If I access `comp1` or `comp2` directly in the template, then there is no issue. If `foo` is declared as a dependency in `comp2`, then there is no issue. If I access `comp1` at least once in `update` method, then everything works.

I sort of understand why this happens. But, why does it break only when there is a `setter` involved?

---

<div class="post-metadata">

**Author:** ![dknutsen](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.emberjs.com/dknutsen/32/16471_2.png) [@dknutsen](https://discuss.emberjs.com/u/dknutsen)\
**Post date:** [October 14, 2019, 5:03pm UTC](https://discuss.emberjs.com/t/computed-property-does-not-update-when-nested-dependent-property-changes-if-computed-setter-is-called/17123/2 "2019-10-14T17:03:08Z")

</div>

I think the problem is that if you set comp2 on init, it never has to calculate comp1 because it caches the comp2 value, but if you don’t set comp2 it gets comp1 and then comp1 will recalculate whenever foo changes. Because comp1 is only used as a dependency of comp2 and never used directly if you short-circuit the comp2 calculation by setting it you never `get` comp1 and because computed properties don’t calculate/recalculate unless they are fetched at least once it never gets calculated and therefore never gets recalculated.

IMO this is an indication that this data flow could probably be refactored to be cleaner and less confusing. That said the computed property optimizations can be tricky and a little confusing, so it’s nice that they will be replaced with tracked properties in the future and hopefully this kind of thing will happen less.