NodeJS中模型的可选更改

Question

I'm using Nodejs with Sequelizejs but I suppose this question could apply to other situations.

An object comes in to my method with a some properties attempting to update the model I pull from the database (if I find a match).

var changes = {
   firstName: "foo",
   loginPin: 0000
}

The model contains many more properties but for the sake of this discussion here is an example.

var existingEmployeeModel = {
    firstName: "bar",
    middleInitial: "f",
    loginPin: 1111,
    email: "foo@bar.com"
}

So right now I basically look at processing it like this:

if (changes.firstName) existingEmployeeModel.firstName = changes.firstName;

Is there a better way to do this? Ocassionally I may .trim() , etc but I can't imagine this is ideal.

Answer 1

For example, lodash apply http://lodash.com/docs#assign function does something similar. Just call it as follows:

_.assign(existingEmployeeModel, changes);

It should copy all the properties from the changes to the model.

If you do not want to add a dependency, you can use this one:

function apply(model, changes) {
  Object.keys(changes).forEach(function (key) {
    if ('string' === typeof changes[key]) {
      model[key] = changes[key].trim();
    } else {
      model[key] = changes[key];
    }
  });
}

Done.