What I try to achieve:
I want to update a value in an obj, which is part of the element of array. See the code below will give you better idea.
There is an issue that I update the value of object, via reference, instead of making a copy. This causes the state behave strangely.
I try to change it to making a copy, but I am not sure.
e.g.
const returnObj = {
...objs,
fields: [{name, value}, {name, value}, {name, value_update_this_only}, ...],
};
// This is the current code
export function* onChange(action) {
// get partial state from redux state
const list = yield select((state) => state.list);
let objs = list[action.index];
// * e.g. objs.fields === [{name, value}, {name, value}, ...]
// * basically following, find the correct field and update its value
// * following has problem, beause we change the value of a reference,
// * instead we should make a new copy, so redux can react
objs.fields.map((field) => {
if (field.name === action.fieldName) {
field["value"] = action.fieldValue;
}
return field;
});
// fire to redux reducer
yield put({
type: "UPDATE",
prop: obj,
docIndex: action.index,
});
}
// the problem: I don't know how to do it in destructing manner.
const returnObj = {
...objs,
fields: [],
};