[Immutable.js] Using fromJS() to Convert Plain JavaScript Objects into Immutable Data-优快云博客

本文介绍了如何使用Immutable.js库从普通的JavaScript对象和数组构建不可变的数据结构。包括将对象转换为Immutable Map，数组转换为Immutable List的方法，并展示了如何通过getIn()方法获取嵌套数据。

Immutable.js offers the fromJS() method to build immutable structures from objects and array. Objects are converted into maps. Arrays are converted into lists. The fromJS() method can also take a reviver function for custom conversions.

Object to Immutable Map:

check by isMap():

    const plainJSObject = {
      title: "Go to grocery",
      text: "I need milk and eggs",
      completed: false,
      category: {title: "House Duties", priority: 10}
    };
    
    const immutableTodo = Immutable.fromJS(plainJSObject);
    
    expect(Immutable.Map.isMap(immutableTodo)).to.be.true

We cat get value by getIn() method:

expect(immtableTodo.getIn(["category", "title"])).to.equal("House Duties");

Array to Immutable List:

check by isList():

    const plainJSArray = [
      "Go to grocery",
      "Buy milk and eggs",
      "Help kids with homework",
      ["Buy Lemons", "Make Lemonade"]
    ];
    
    const immutableTodoList = Immutable.fromJS(plainJSArray);
    expect(Immutable.List.isList(immutableTodoList)).to.be.true;

get value by getIn():

expect(immutableTodoList.getIn([3, 1])).to.equal("Make Lemonade")

Convert a plain array to Immutable Map:

    const plainJSArray = [
      "Go to grocery",
      "Buy milk and eggs",
      "Help kids with homework",
      ["Buy Lemons", "Make Lemonade"]
    ];

    const immutableTodoList = Immutable.formJS(plainJSArray, (key, value)=>{

         return value.toMap();
    });


    expect(immutableTodoList.getIn([3,1])).to.equal("Make Lemonade");

转载于:https://www.cnblogs.com/Answer1215/p/5205810.html