CAP Service SDK for Node.js

Reference Documentation

Introduction

As an application developer you’d primarily use the Node.js APIs documented herein to implement domain-specific custom logic along these lines:

1. Define services in CDS → see Cookbook > Providing & Consuming Services
2. Add service implementations → cds.Service > Implementations
3. Register custom event handlers in which → srv.on/before/after
4. Read/write data from other services in which → srv.run + cds.ql
5. …, i.e. from your primary database → cds.DatabaseService
6. …, i.e. from other connected services → cds.RemoteService

All the rest is largely handled by the CAP runtime framework behind the scenes. This especially applies to bootstrapping the cds.server and the generic features provided through cds.ApplicationService.

Content

• The cds Facade Object
• cds.Service APIs
• cds.Events
• cds.ql → queries
• cds.log → logging
• cds.env → config
• cds.serve… ⇢ service(s)
• cds.connect ⇢ service
• cds.compile… ⇢ model
• cds.reflect ⇢ linked model
• cds.test → testing
• req.user — Authentication
• srv.tx — Transactions
• Best Practices
• Using Typescript
• @sap/cds-dk APIs

Conventions

We use the following notations in method signatures:

Read them as follows:

• param? — appended question marks denote optional parameters
• → result — solid line arrows: returns the given result
• ⇢ result — dashed arrows: returns a [Promise] resolving to the given result
• ... — denotes a fluent API, eventually returning/resolving to given result
• ↳ — denotes subsequent methods to add options in a fluent API