具有特定值的Mongoose模式属性

Question

Here's my code:

var userSchema = new mongoose.Schema({
  email: String,
  password: String,
  role: Something
});

My goal is to define the role property to have specific values ('admin', 'member', 'guest' and so on..), what's the better way to achieve this? Thanks in advance!

Answer 1

You can do enum.

var userSchema = new mongoose.Schema({
  // ...
  , role: { type: String, enum: ['admin', 'guest'] }
}

var user = new User({
 // ...
 , role: 'admin'
});

Answer 2

There isn't really a way that I know of to have specific values possible for role, but maybe you'd like to create multiple object types based off of a master object type, each with their own roles (and anything else you want to distinguish). For example...

var userSchema = function userSchema() {};
userSchema.prototype = {
  email: String,
  password: String,
  role: undefined
}
var member = function member() {};
member.prototype = new userSchema();
member.prototype.role = 'member';

var notSupposedToBeUsed = new userSchema();
var billTheMember = new member();
console.log(notSupposedToBeUsed.role); // undefined
console.log(billTheMember.role); // member

Another possibility is have userSchema with a constructor that easily allows you to select one of the built in values. An example...

var userSchema = function userSchema(role) {
    this.role = this.role[role];
    // Gets the value in userSchema.role based off of the parameter
};
userSchema.prototype = {
  email: String,
  password: String,
  role: { admin: 'admin', member: 'member', guest: 'guest' }
}
var a = new userSchema('admin');
var b = new userSchema('blah');
console.log(a.role); // 'admin'
console.log(b.role); // undefined

More: http://pivotallabs.com/users/pjaros/blog/articles/1368-javascript-constructors-prototypes-and-the-new-keyword