Ottoman.js

This section is for those who want to understand how Ottoman works in depth.

# Key Generation Layer

Ottoman provides an abstraction layer to handle the keys that will be used to store/access the documents on the Database Server.

Developers will only have to work with the document ids while ottoman handles the keys automatically for them.

# keyGenerator function

The default keyGenerator function is used to generate all keys by Ottoman in your Couchbase datastore.

const keyGenerator = ({metadata}) => `${metadata.modelName}`

Using the default keyGenerator function that Ottoman provides and assuming your modelName is 'User', the key for your document would look like:

  • User::0477024c

Notice

This resulted key is a combination of the prefix as provided by the default keyGenerator function (${metadata.modelName}) appended with an ID (0477024c).

# Override keyGenerator function

The keyGenerator function allows you to only override the prefix for a key, or completely remove the prefix such that the key always matches the ID of the document generated.

const keyGenerator = ({metadata}) => `${metadata.scopeName}`
const User = model('User', schema, { keyGenerator, scopeName: 'myScope' })

In this example we are overiding the keyGenerator function and replacing the ${metadata.modelName} with ${metadata.scopeName}. Using this override, the key for your document would look like:

  • myScope::0477024c

To understand how ID differs from keys in Ottoman we need to explore creating a model, understand how Ottoman deals with IDs which affect your key and then how to retrieve your document by ID.

# Defining a Model

...
const userSchema = new Schema({ name: string });
const User = model('User', userSchema);
  1. Set your rules in the Schema.
  2. Now you can create your Model with the Schema defined.

# Creating a document

Let see how Ottoman handles a new document creation.

How to Use

Notice

Using Ottoman you only need to think about id in order to execute CRUD Operations over documents. All the key management will be automatically handled by Ottoman.

# Retrieving a document

Ottoman provides a findById method at the Model level to retrieve a document by id. See the picture below to understand how it works.

How to Use