I have a function that loops over an array of objects and builds an object depending on some parameters. It should return the build object
which represents a state object of a component that I will set. However, I would like to use the Array.foreach
but I have no idea how to call the function after the foreach loop is done.
The function looks something like this:
buildStateObject= (someArray: Array) => {
let stateobject= {};
someArray.foreach(item => {
switch (item.Someparameter) {
case 1:
stateobject.someProp1= item.message;
break;
case 2:
stateobject.someProp2= item.message;
break;
// code omitted
}
});
return stateobject;
};
and in my component I have something like this which obviously does not work :
if(someJson.jsonArray)
this.setState(this.buildStateObject(someJson));
So what I am looking for is something like this:
Promise.all(buildStateObject).
then((theResultObjectMaybe)=>{this.setState(theResultObjectMaybe);})
I tried to figure this out but I was not able to. I am also not sure if this is a good practice todo.
[Edit]
@PaulJanicki thank you for pointing the error out. There were just type errors. However one error you pointed out was also in my code which results in a Unhandled promise rejection
and I assumed this was because the forEac
h was async and the result was not yet processed.
The problem was a type error foreach
instead of the correct forEach
You are missing the return statement outside of the forEach method, in the buildStateObject
function. Also forEach
should be camelCase.
function buildStateObject(someArray) {
let stateobject = {};
someArray.forEach(item => {
switch (item.someparameter) {
case 1:
stateobject.someProp= item.message;
break;
case 2:
stateobject.someProp= item.message;
break;
// code omitted
}
});
return stateobject;
}
function setState(state) {
console.log(state);
}
var someJson = [{
message: 'first',
someparameter: 1
}, {
message: 'second',
someparameter: 2
}]
setState(buildStateObject(someJson))
Also consider that stateobject.someProp
will be overwritten with each loop execution, not sure if that's the intended behaviour.