Can a getter return data from 2 different sources

Asked Aug 30 '18 at 21:04

Active Aug 30 '18 at 22:05

Viewed 54 times

can I have a getter which can match 2 different sources?

I have an array of commands.Each command is an object (JSON):

Commands= [{
opCode: anOpCode,
field: aField,// matching the field in html
parser: 'referenceToAfunction',
params:aParam, //the param can be null or have some value
value: null//I have a getter to that value
}, //many other commands...]

The ViewModel (getters from my commands):

    Object.defineProperty(VM, aField, {
      get: function () {
        return Commands.find(function(cmd) {
              if(cmd.field == aField)
                 return cmd.value;
             });
         }
    });

I have some specials commands where 2 different params match the same field in html.

In my array it will be 2 different object (where only params value is different), but I would like the getter to be updated if any of them changes

edited Aug 30 '18 at 22:05

asked Aug 30 '18 at 21:04

IsraGab

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A getter can do whatever it wants to find the result. – Barmar Aug 30 '18 at 21:56
You have a syntax error in your call to `defineProperty()`. – Barmar Aug 30 '18 at 21:57
Did you mean `Object.defineProperty(VM, 'aField', {`? – Barmar Aug 30 '18 at 21:58
The getter should refer to `this` so it's getting from the correct object. – Barmar Aug 30 '18 at 22:00
i fixed the syntax error. my question isn't because my code wasn't working but more how to do that... – IsraGab Aug 30 '18 at 22:00
What is `Commands` and how does it relate to the object you're trying to get from? – Barmar Aug 30 '18 at 22:01
What is the value of `aField` when you call `Object.defineProperty()`? – Barmar Aug 30 '18 at 22:02
Commands is the array I defined. I have updated the question. is it understandable now ? – IsraGab Aug 30 '18 at 22:06
It's still not clear how it relates to the `VM` object. You want `VM.foo` to return the value from the element of `Commands` where `field = "foo"`? – Barmar Aug 30 '18 at 22:07
valueofafield is null or undefined. Is getting defined on server response – IsraGab Aug 30 '18 at 22:08
that is exactly what I want. but i can have two or more elements where field=='foo' – IsraGab Aug 30 '18 at 22:11
for same field in VM, server can send notification with different params – IsraGab Aug 30 '18 at 22:13
A getter can only return one thing at a time, unless you want to return an array. – Barmar Aug 30 '18 at 22:14
it's like an alias – IsraGab Aug 30 '18 at 22:14

Can a getter return data from 2 different sources

0 Answers0