Generically create object in Javascript from a string class name

Question

Is it possible to create an object in Javascript generically from a string class name similar to Java? Maybe some type of Factory?

I want a database to hold a list of class names. Each class name will be associated with a user friendly name. These user friendly names would populate a menu. When a user selects a menu item, the respective class name will be retrieved and the class (object) created. I currently do something similar in Java.

For example, instead of

var obj = new demo.view.CustomObject({});

I would like something like this

var obj = Factory.create('demo.view.CustomObject', params);

Thank you

Arash Milani Arash Milani · Accepted Answer · 2017-01-13T03:18:07

What you are looking for is using bracket notation to access object properties using a string. Here I have created a factory method that splits the string by dot. Then using array reduce I get into the constructor function and finally create the object.

function construct(constructorPath, params) {
  var constructorFunc = constructorPath.split('.')
    .reduce((prev, next) => prev[next], window)
  return new constructorFunc(params)
}

// Usage:
var obj = construct('demo.view.CustomObject', someParams)

Generically create object in Javascript from a string class name

1 Answers