Create a Data Model

Enable Development Mode Sync

Development Mode is set in the App Services UI.

To enable Development Mode, click the slider to the right of Development Mode.

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Edit Your Realm Object Schema

As you continue to develop your application, you will need to modify your data model with it to enforce different data validation rules based on those changes. While Development Mode is on, you can edit your Realm Object Schema in your client code. Data Validation occurs when Development Mode is off, so App Services does not accept changes to your Realm Object Schema while Development Mode is not on.

const realmObjectModel = {
  name: 'User',
  properties: {
    _id: 'objectId',
    _partition: 'string',
    name: 'string',
    // developers set optional: true to adhere to the new requirement
    birthday: {type: 'date', optional: true},
  },
  primaryKey: '_id'
};
Realm.open({schema: realmObjectModel, sync: {/*...*/}})
  .then(realm => {
    // ... use the realm instance to read and modify data
  })

Update Your App Services Schema with the Realm Object Schema Changes

While Development Mode is on, App Services doesn't validate writes against your data model, allowing you to freely update your Realm Object Model. When you turn off Development Mode, MongoDB App Services automatically updates your App Services Schema and starts to enforce data validation for your Atlas cluster based on it.

In the Sync screen, turn off Development Mode by clicking the slider next to Development Mode. The UI indicates that Development Mode has been turned off.

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Define an App Services Schema

To get started, ensure you have an App Services Schema defined. App Services will translate this App Services Schema into a Realm Object Schema to be configured and utilized in your mobile application.

Note the following requirements:

• The App Services Schema must have a primary key field called _id. _id can be of type string, int, or objectId.

• Your schema object type names cannot exceed 57 UTF-8 characters.

View the Realm Object Schema

The Realm Object Schema defines and validates your data in your mobile client application. To view your Realm Object Schema, navigate to the Atlas Device SDKs page, then click the Realm Object Models tab. On this page, you can view your App Services Schema as a generated Realm Object Schema in your language of choice.

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Open a Realm with the Realm Object Schema

You can use the generated Realm Object Schema in your client application. In order to begin enforcing data validation with your data model, you can open a realm with the Realm Object Schema. This will prevent improper data from entering your database from your mobile client.

Click Copy on the right-hand side of the Realm Object Schema for the Object Model you want to integrate into your mobile application code. This will copy the Realm Object Schema code for the SDK of your choice into your clipboard.

Open your mobile application code in your IDE and paste the Realm Object Schema code in.

const UserSchema = { // your copied and pasted Realm Object Schema
  name: 'User',
  properties: {
    _id: 'objectId',
    _partition: 'string',
    name: 'string',
    birthday: 'date'
  },
  primaryKey: '_id'
};
// Initialize a realm with your Realm Object Schema
Realm.open({schema: UserSchema, sync: { /* ... */ }})
  .then(realm => {
    // ... use the realm instance to read and modify data
  })