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Nesting Classes

Differences from Mongoose​

Typegoose Nesting is slightly different from mongoose, the following will show a basic mongoose schema which has nesting and how it would be translated to typegoose.

const AnimalSchema = new mongoose.Schema({
  name: String,
  properties: {
    hasEaten: Boolean,
    nicknames: [String]
  }
});

It is required to put nested properties in their own class because of how typescript reflection works, it currently just translates { someprop: string } to Object in reflection.

Also, under the hood, typegoose creates the schemas that would be equivalent to writing:

const PropertiesSchema = new mongoose.Schema({
  hasEaten: {
    type: Boolean
  },
  nicknames: [{
    type: String
  }]
});

const AnimalSchema = new mongoose.Schema({
  name: {
    type: String
  },
  properties: {
    type: PropertiesSchema
  }
});
note

Typegoose does not support native "nested paths" (unless using Passthrough), each class in typegoose will be a nested schema (each class is its own Schema instance), so it is not a 1:1 translation of the initial mongoose example to typegoose, but similar enough to initially think that way.

Using the Passthrough Class​

danger

It is not recommended to use the Passthrough Class unless explicitly required to workaround something. In case you have found a problem that could only be solved with the Passthrough class, please open a new issue in the typegoose repository so that we can fix having to use the Passthrough Class.

In Typegoose there also exists a special class called Passthrough which can be used to write a mongoose schema-like directly, without typegoose processing it.

Here is a Example of how a mongoose schema would look like writing it with Passthrough:

Mongoose Initial Schema:

const AnimalSchema = new mongoose.Schema({
  name: String,
  properties: {
    hasEaten: Boolean,
    nicknames: [String]
  }
});

With Passthrough and the Direct mode, the typegoose class above is fully equivalent in how it is given to mongoose as the mongoose schema example.

Difference to References​

In Typegoose, references and subdocuments are written similarly:

class Animal {
  @prop()
  public name?: string;

  @prop()
  public properties?: Properties;
}

class Properties {
  @prop()
  public hasEaten?: boolean;

  @prop({ type: String })
  public nicknames?: string[];
}

For more on referencing other classes, read Reference other Classes.