How can I track deep properties/objects change by using reaction?

[mannok]

By using deepObserve we can track any nested properties/objects change. However, I don't find there is one for reaction? May I know if the can track deep properties/objects change by using reaction?

[mweststrate]

MobX tracks anything you access. So by merely reading the properties you are interested in, it will start observing them. With autorun that happens for the entire callback function, for react that happens for everything you access in the first function you pass it.

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On Wed, Apr 5, 2023 at 12:48 PM Xanthus Wong ***@***.***> wrote: By using deepObserve <https://github.com/mobxjs/mobx-utils#deepobserve> we can track any nested properties/objects change. However, I don't find there is one for reaction? May I know if the can track deep properties/objects change by using reaction? — Reply to this email directly, view it on GitHub <#3677>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAN4NBD6DP57VM6DZPJF6C3W7VLZNANCNFSM6AAAAAAWT63NJE> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[mannok]

@mweststrate thanks for help. However, for my case, I want to know if any of the object's nested property has been updated while the object has dynamic shape, by then I will trigger an alert to user. That means I am not accessing to any specific property of the object, what I need is whether there is any change under the the grand children of the objects

[mweststrate]

In that case access all the grandchildren

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On Wed, 5 Apr 2023, 16:38 Xanthus Wong, ***@***.***> wrote: @mweststrate <https://github.com/mweststrate> thanks for help. However, for my case, I want to know if any of the object's nested property has been updated while the object has dynamic shape, by then I will trigger an alert to user. That means I am not accessing to any specific property of the object, what I need is whether there is any change under the the grand children of the objects — Reply to this email directly, view it on GitHub <#3677 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAN4NBBIBOESVCKDRZNP4OLW7WGYZANCNFSM6AAAAAAWT63NJE> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[mannok]

@mweststrate In my case the target object has dynamic data shape, so I am not able to know what grandchildren properties should be accessed

[mweststrate]

Sorry, I'm missing how that is relevant. You can loop over them like you'd do in any other place you'd be using them? Any normal JS approach to iterating whatever data structure you have should work, as long as the iteration isn't async.

[mweststrate]

e.g. for (const key of obj) obj[key] etc. etc. is all tracked

[mannok]

This could run into infinite circular dependency. Also, as I don't know the data shape of the target object, it can only be determined at runtime, it may contains nested object and nested property. The above solution assumed we know it at coding time and only 1 level of nested object

[mweststrate]

Reflecting on runtime is completely fine, how you traverse is up to you, for MobX it doesn't matter, it will track with your traversal at runtime.

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On Wed, 5 Apr 2023, 19:27 Xanthus Wong, ***@***.***> wrote: This could run into infinite circular dependency. Also, as I don't know the data shape of the target object, it can only be determined at runtime, it may contains nested object and nested property. The above solution assumed we know it at coding time and only 1 level of nested object — Reply to this email directly, view it on GitHub <#3677 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAN4NBFKOFTCKVBSRSGSMX3W7W2SVANCNFSM6AAAAAAWT63NJE> . You are receiving this because you were mentioned.Message ID: ***@***.***>