Question

我有ImmutableJS Record，我想更新多个字段，推荐的方式是什么？

我试过withMutations但由于某种原因，我得到的副本是空的，我不能改变它：

const UserRecord = Record({
  firstName: null,
  lastName: null, 
  address: {
    city: null, 
    zipCode: null
  }
});

export function createUserRecord(data) {
  return new UserRecord(fromJS(data));
}

let u = createUserRecord({
  firstName: 'John',
  lastName: 'Don', 
  address: {
    city: 'New York', 
    zipCode: 1111
  }
});

let newU = u.withMutations((uCopy) => {
  // uCopy is empty (with default values)
  uCopy.set('firstName', 'New FirstName');
  uCopy.set('lastName', 'New LastName');
  // uCopy is still empty (not mutated)
});

console.log(u.toJS()); // {firstName: "John", lastName: "Don", address: {city: null, zipCode: null}}
console.log(newU.toJS()); // {firstName: null, lastName: null, address: {city: null, zipCode: null}}

谢谢！

Answer 1

方法withMutations不会更改对象u。它改为返回一个变异的对象，所以你需要像这样调用它

let newU = u.withMutations((uCopy) => {
  // uCopy is empty (with default values)
  uCopy.set('firstName', 'New FirstName');
  uCopy.set('lastName', 'New LastName');
  // uCopy is still empty (not mutated)
});

在https://facebook.github.io/immutable-js/

的文档中查看此示例

var list1 = Immutable.List.of(1,2,3);
var list2 = list1.withMutations(function (list) {
  list.push(4).push(5).push(6);
});
assert(list1.size === 3);
assert(list2.size === 6);

更新ImmutableJS Record的多个字段的推荐方法是什么？

1 个答案: