在打字稿类构造函数中将值动态设置为“this”

Question

Here is a simplified class. I try to loop over key values in constructor, to dynamically assign values to this. But it doesn't work. Is it a syntax problem ? Or is it not possible ?

class DirectoryModel {

    public link_title: string
    public link_desc: string

    constructor(fields: any) {
        console.log(fields) // ok
        _.forOwn(fields, function (value, key) {
            console.log(key) // ok
            console.log(value) // ok
            this[key] = value // "Cannot set property 'link_title' of undefined"
        })

       // this.link_title = fields.link_title
       // this.link_desc = fields.link_desc
    }
}

Answer 1

As Yasser commented, this is not bound to your DirectoryModel. Use arrow functions to bind this to your instance:

class DirectoryModel
{

    public link_title: string
    public link_desc: string

    constructor(fields: any)
    {
        _.forOwn(fields, (value, key) => //This binds `this`
        {
            this[key] = value
        })
    }
}