JS How to check if a class variable changed?
I have a variable in a class that can change at any time? Is there a way that js can reactively check if it changed and if it did perform a function? I don't have control of the object, I can view it and modify it, but my code is not the only code that can do that.
javascript meteor javascript-events meteor-blaze
asked Nov 16 '18 at 0:08
user10011538user10011538
216
add a comment |
I have a variable in a class that can change at any time? Is there a way that js can reactively check if it changed and if it did perform a function? I don't have control of the object, I can view it and modify it, but my code is not the only code that can do that.
javascript meteor javascript-events meteor-blaze
asked Nov 16 '18 at 0:08
user10011538user10011538
216
You can manage the way this variable changes, like for example make any changes to this variable only through a certain function, in which you change the value, and do any other checks or changes you like in it.
– Ahmed Hammad
Nov 16 '18 at 0:13
I don't manage the variable, I can just view it.
– user10011538
Nov 16 '18 at 0:24
Well, one costly solution, is to run an interval every short perion of time, which checks on the value of this variable and act upon change. But don’t do this unless the change to the variable is frequent.
– Ahmed Hammad
Nov 16 '18 at 0:31
@user10011538 I provided you a Meteor specific answer below. Did it help you to solve your issue? If not please provide more detail so we can work this out.
– Jankapunkt
Dec 19 '18 at 9:32
add a comment |
I have a variable in a class that can change at any time? Is there a way that js can reactively check if it changed and if it did perform a function? I don't have control of the object, I can view it and modify it, but my code is not the only code that can do that.
javascript meteor javascript-events meteor-blaze
asked Nov 16 '18 at 0:08
user10011538user10011538
216
I have a variable in a class that can change at any time? Is there a way that js can reactively check if it changed and if it did perform a function? I don't have control of the object, I can view it and modify it, but my code is not the only code that can do that.
javascript meteor javascript-events meteor-blaze
javascript meteor javascript-events meteor-blaze
asked Nov 16 '18 at 0:08
user10011538user10011538
216
asked Nov 16 '18 at 0:08
user10011538user10011538
216
edited Nov 16 '18 at 0:24
user10011538
asked Nov 16 '18 at 0:08
user10011538user10011538
216
asked Nov 16 '18 at 0:08
user10011538user10011538
216
asked Nov 16 '18 at 0:08
user10011538user10011538
216
216
You can manage the way this variable changes, like for example make any changes to this variable only through a certain function, in which you change the value, and do any other checks or changes you like in it.
– Ahmed Hammad
Nov 16 '18 at 0:13
I don't manage the variable, I can just view it.
– user10011538
Nov 16 '18 at 0:24
Well, one costly solution, is to run an interval every short perion of time, which checks on the value of this variable and act upon change. But don’t do this unless the change to the variable is frequent.
– Ahmed Hammad
Nov 16 '18 at 0:31
@user10011538 I provided you a Meteor specific answer below. Did it help you to solve your issue? If not please provide more detail so we can work this out.
– Jankapunkt
Dec 19 '18 at 9:32
add a comment |
You can manage the way this variable changes, like for example make any changes to this variable only through a certain function, in which you change the value, and do any other checks or changes you like in it.
– Ahmed Hammad
Nov 16 '18 at 0:13
I don't manage the variable, I can just view it.
– user10011538
Nov 16 '18 at 0:24
Well, one costly solution, is to run an interval every short perion of time, which checks on the value of this variable and act upon change. But don’t do this unless the change to the variable is frequent.
– Ahmed Hammad
Nov 16 '18 at 0:31
@user10011538 I provided you a Meteor specific answer below. Did it help you to solve your issue? If not please provide more detail so we can work this out.
– Jankapunkt
Dec 19 '18 at 9:32
You can manage the way this variable changes, like for example make any changes to this variable only through a certain function, in which you change the value, and do any other checks or changes you like in it.
– Ahmed Hammad
Nov 16 '18 at 0:13
You can manage the way this variable changes, like for example make any changes to this variable only through a certain function, in which you change the value, and do any other checks or changes you like in it.
– Ahmed Hammad
Nov 16 '18 at 0:13
I don't manage the variable, I can just view it.
– user10011538
Nov 16 '18 at 0:24
I don't manage the variable, I can just view it.
– user10011538
Nov 16 '18 at 0:24
Well, one costly solution, is to run an interval every short perion of time, which checks on the value of this variable and act upon change. But don’t do this unless the change to the variable is frequent.
– Ahmed Hammad
Nov 16 '18 at 0:31
Well, one costly solution, is to run an interval every short perion of time, which checks on the value of this variable and act upon change. But don’t do this unless the change to the variable is frequent.
– Ahmed Hammad
Nov 16 '18 at 0:31
@user10011538 I provided you a Meteor specific answer below. Did it help you to solve your issue? If not please provide more detail so we can work this out.
– Jankapunkt
Dec 19 '18 at 9:32
@user10011538 I provided you a Meteor specific answer below. Did it help you to solve your issue? If not please provide more detail so we can work this out.
– Jankapunkt
Dec 19 '18 at 9:32
add a comment |
2 Answers
2
active
oldest
votes
If you are the owner of this object you can use Proxy object on it to be used instead of original object. And this case you will have the total control on every single operation is produced with your object
answered Nov 16 '18 at 0:19
bva inbbva inb
212
Sorry I did not mention this, I don't have absolute control of the object, I can view it and modify it, but my code is not the only code that can do that.
– user10011538
Nov 16 '18 at 0:25
add a comment |
In Meteor (you have tagged it) you have the Tracker which autoruns a function if a reactive data source has been changed, no matter by whom or what.
Read: https://docs.meteor.com/api/tracker.html
Now in Blaze (which you have also tagged) you have also a Template internal Tracker:
Template.myTemplate.onCreated(function (){
const instance = this
instance.autorun(() => {
// this behaves like Tracker.autorun
})
})
How to to make a variable reactive?
If you access a reactive variable inside an autorun, you trigger the given function. A normal Object is not reactive. In Meteor you can store data using
ReactiveVar: https://docs.meteor.com/api/reactive-var.html
ReactiveDict: https://atmospherejs.com/meteor/reactive-dict
(Mini)mongo Cursor: https://docs.meteor.com/api/collections.html#mongo_cursor
Accessing data from these data stores triggers computations of your trackers.
Reading these docs should make it clear to understand the reactive concept of Meteor and you should be able to write a reactive Template.
answered Nov 16 '18 at 6:56
JankapunktJankapunkt
4,09531835
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
If you are the owner of this object you can use Proxy object on it to be used instead of original object. And this case you will have the total control on every single operation is produced with your object
answered Nov 16 '18 at 0:19
bva inbbva inb
212
Sorry I did not mention this, I don't have absolute control of the object, I can view it and modify it, but my code is not the only code that can do that.
– user10011538
Nov 16 '18 at 0:25
add a comment |
If you are the owner of this object you can use Proxy object on it to be used instead of original object. And this case you will have the total control on every single operation is produced with your object
answered Nov 16 '18 at 0:19
bva inbbva inb
212
Sorry I did not mention this, I don't have absolute control of the object, I can view it and modify it, but my code is not the only code that can do that.
– user10011538
Nov 16 '18 at 0:25
add a comment |
If you are the owner of this object you can use Proxy object on it to be used instead of original object. And this case you will have the total control on every single operation is produced with your object
answered Nov 16 '18 at 0:19
bva inbbva inb
212
If you are the owner of this object you can use Proxy object on it to be used instead of original object. And this case you will have the total control on every single operation is produced with your object
answered Nov 16 '18 at 0:19
bva inbbva inb
212
answered Nov 16 '18 at 0:19
bva inbbva inb
212
answered Nov 16 '18 at 0:19
bva inbbva inb
212
answered Nov 16 '18 at 0:19
bva inbbva inb
212
212
Sorry I did not mention this, I don't have absolute control of the object, I can view it and modify it, but my code is not the only code that can do that.
– user10011538
Nov 16 '18 at 0:25
add a comment |
Sorry I did not mention this, I don't have absolute control of the object, I can view it and modify it, but my code is not the only code that can do that.
– user10011538
Nov 16 '18 at 0:25
Sorry I did not mention this, I don't have absolute control of the object, I can view it and modify it, but my code is not the only code that can do that.
– user10011538
Nov 16 '18 at 0:25
Sorry I did not mention this, I don't have absolute control of the object, I can view it and modify it, but my code is not the only code that can do that.
– user10011538
Nov 16 '18 at 0:25
add a comment |
In Meteor (you have tagged it) you have the Tracker which autoruns a function if a reactive data source has been changed, no matter by whom or what.
Read: https://docs.meteor.com/api/tracker.html
Now in Blaze (which you have also tagged) you have also a Template internal Tracker:
Template.myTemplate.onCreated(function (){
const instance = this
instance.autorun(() => {
// this behaves like Tracker.autorun
})
})
How to to make a variable reactive?
If you access a reactive variable inside an autorun, you trigger the given function. A normal Object is not reactive. In Meteor you can store data using
ReactiveVar: https://docs.meteor.com/api/reactive-var.html
ReactiveDict: https://atmospherejs.com/meteor/reactive-dict
(Mini)mongo Cursor: https://docs.meteor.com/api/collections.html#mongo_cursor
Accessing data from these data stores triggers computations of your trackers.
Reading these docs should make it clear to understand the reactive concept of Meteor and you should be able to write a reactive Template.
answered Nov 16 '18 at 6:56
JankapunktJankapunkt
4,09531835
add a comment |
In Meteor (you have tagged it) you have the Tracker which autoruns a function if a reactive data source has been changed, no matter by whom or what.
Read: https://docs.meteor.com/api/tracker.html
Now in Blaze (which you have also tagged) you have also a Template internal Tracker:
Template.myTemplate.onCreated(function (){
const instance = this
instance.autorun(() => {
// this behaves like Tracker.autorun
})
})
How to to make a variable reactive?
If you access a reactive variable inside an autorun, you trigger the given function. A normal Object is not reactive. In Meteor you can store data using
ReactiveVar: https://docs.meteor.com/api/reactive-var.html
ReactiveDict: https://atmospherejs.com/meteor/reactive-dict
(Mini)mongo Cursor: https://docs.meteor.com/api/collections.html#mongo_cursor
Accessing data from these data stores triggers computations of your trackers.
Reading these docs should make it clear to understand the reactive concept of Meteor and you should be able to write a reactive Template.
answered Nov 16 '18 at 6:56
JankapunktJankapunkt
4,09531835
add a comment |
In Meteor (you have tagged it) you have the Tracker which autoruns a function if a reactive data source has been changed, no matter by whom or what.
Read: https://docs.meteor.com/api/tracker.html
Now in Blaze (which you have also tagged) you have also a Template internal Tracker:
Template.myTemplate.onCreated(function (){
const instance = this
instance.autorun(() => {
// this behaves like Tracker.autorun
})
})
How to to make a variable reactive?
If you access a reactive variable inside an autorun, you trigger the given function. A normal Object is not reactive. In Meteor you can store data using
ReactiveVar: https://docs.meteor.com/api/reactive-var.html
ReactiveDict: https://atmospherejs.com/meteor/reactive-dict
(Mini)mongo Cursor: https://docs.meteor.com/api/collections.html#mongo_cursor
Accessing data from these data stores triggers computations of your trackers.
Reading these docs should make it clear to understand the reactive concept of Meteor and you should be able to write a reactive Template.
answered Nov 16 '18 at 6:56
JankapunktJankapunkt
4,09531835
In Meteor (you have tagged it) you have the Tracker which autoruns a function if a reactive data source has been changed, no matter by whom or what.
Read: https://docs.meteor.com/api/tracker.html
Now in Blaze (which you have also tagged) you have also a Template internal Tracker:
Template.myTemplate.onCreated(function (){
const instance = this
instance.autorun(() => {
// this behaves like Tracker.autorun
})
})
How to to make a variable reactive?
If you access a reactive variable inside an autorun, you trigger the given function. A normal Object is not reactive. In Meteor you can store data using
ReactiveVar: https://docs.meteor.com/api/reactive-var.html
ReactiveDict: https://atmospherejs.com/meteor/reactive-dict
(Mini)mongo Cursor: https://docs.meteor.com/api/collections.html#mongo_cursor
Accessing data from these data stores triggers computations of your trackers.
Reading these docs should make it clear to understand the reactive concept of Meteor and you should be able to write a reactive Template.
answered Nov 16 '18 at 6:56
JankapunktJankapunkt
4,09531835
answered Nov 16 '18 at 6:56
JankapunktJankapunkt
4,09531835
answered Nov 16 '18 at 6:56
JankapunktJankapunkt
4,09531835
answered Nov 16 '18 at 6:56
JankapunktJankapunkt
4,09531835
4,09531835
add a comment |
add a comment |
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You can manage the way this variable changes, like for example make any changes to this variable only through a certain function, in which you change the value, and do any other checks or changes you like in it.
– Ahmed Hammad
Nov 16 '18 at 0:13
I don't manage the variable, I can just view it.
– user10011538
Nov 16 '18 at 0:24
Well, one costly solution, is to run an interval every short perion of time, which checks on the value of this variable and act upon change. But don’t do this unless the change to the variable is frequent.
– Ahmed Hammad
Nov 16 '18 at 0:31
@user10011538 I provided you a Meteor specific answer below. Did it help you to solve your issue? If not please provide more detail so we can work this out.
– Jankapunkt
Dec 19 '18 at 9:32