Custom Handlers

andrew.js

const cds = require('@sap/cds')
class northbreeze { 
  async selectProduct(req) {  
    const { communityid } = req.data  
    ...
    const { ProductName } = await SELECT.one.from(Products).columns(....)  
    return `${ProductName}` }
}
module.exports = northbreeze

custom.js

// Style 1 - Function no extending 
module.exports = function Sue(){
  this.on('sum', ({data:{x,y}}) => x+y)
  this.on('add', ({data:{x,to}}) => stocks[to] += x)
  this.on('stock', ({data:{id}}) => stocks[id])
  this.on('getStock','Foo', ({params:[id]}) => stocks[id])
  this.on('order','Foo', ({params:[id],data:{x}}) => stocks[id] -= x)
}
// Style 2 - Extending cds.Service ( and sometimes I see extending cds.ApplicationService )
module.exports = class Sue extends cds.Service {
  sum(x,y) { return x+y }
  add(x,to) { return stocks[to] += x }
  stock(id) { return stocks[id] }
  getStock(Foo,id) { return stocks[id] }
  order(Foo,id,x) { return stocks[id] -= x }  
}