Files
cloud-cap-samples/bookshop/server.js
Christian Georgi f593265687 Cosmetics
2020-11-14 21:56:08 +01:00

59 lines
2.0 KiB
JavaScript

const {resolve} = require ('path')
const {promisify} = require('util')
const readFile = promisify(require('fs').readFile)
const swaggerUi = require ('swagger-ui-express')
const cds = require ('@sap/cds')
const trace = cds.debug('openapi')
let app, host, docCache={}
cds
.on ('bootstrap', _app => { app = _app })
.on ('serving', service => {
const apiPath = '/api-docs'+service.path
console.log (`[Open API] - serving ${service.name} at ${apiPath}`)
app.use(apiPath, async (req, _, next) => {
req.swaggerDoc = await toOpenApiDoc(service, host, docCache)
next()
}, swaggerUi.serve, swaggerUi.setup())
addLinkToIndexHtml(service, apiPath)
})
.on ('listening', ({server})=> { host = 'localhost:'+server.address().port })
async function toOpenApiDoc(service, host, cache) {
if (!cache[service.name]) {
const spec = await openApiFromFile(service, host)
if (spec) { // pre-compiled spec file available?
cache[service.name] = spec
}
else if (cds.compile.to.openapi) { // on-the-fly exporter available?
trace && trace ('Compiling Open API spec for', service.name)
cache[service.name] = cds.compile.to.openapi (service.model, {
service: service.name,
'openapi:url': service.path,
'openapi:diagram': true
})
}
}
return cache[service.name]
}
async function openApiFromFile(service) {
const fileName = resolve(`srv/${service.name}.openapi3.json`)
const file = await readFile(fileName).catch(()=>{/*no such file*/})
if (file) {
trace && trace ('Using Open API spec from file', fileName)
return JSON.parse(file)
}
}
function addLinkToIndexHtml(service, apiPath) {
const provider = (entity) => {
if (entity) return // avoid link on entity level, looks too messy
return { href:apiPath, name:'Swagger UI', title:'Show in Swagger UI' }
}
service.$linkProviders ? service.$linkProviders.push(provider) : service.$linkProviders = [provider]
}
module.exports = cds.server