69 lines
2.2 KiB
JavaScript
69 lines
2.2 KiB
JavaScript
// Serves a Swagger UI with API definitions either created on the fly
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// or loaded from file system.
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//
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// Needs @sap/cds-dk >= 3.3.0 installed
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const {resolve} = require ('path')
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const {promisify} = require('util')
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const readFile = promisify(require('fs').readFile)
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const swaggerUi = require ('swagger-ui-express')
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const cds = require ('@sap/cds')
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const cors = require('cors')
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const debug = cds.debug('openapi')
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let app, docCache={}
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cds
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.on ('bootstrap', _app => {
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app = _app
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app.use(cors()) // allow to be called from e.g. editor.swagger.io
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})
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.on ('serving', service => {
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const apiPath = '/api-docs'+service.path
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console.log (`[Open API] - serving ${service.name} at ${apiPath}`)
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app.use(apiPath, async (req, _, next) => {
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req.swaggerDoc = await toOpenApiDoc(service, docCache)
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next()
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}, swaggerUi.serve, swaggerUi.setup())
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addLinkToIndexHtml(service, apiPath)
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})
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async function toOpenApiDoc(service, cache) {
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if (!cache[service.name]) {
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const spec = await openApiFromFile(service)
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if (spec) { // pre-compiled spec file available?
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cache[service.name] = spec
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}
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// On-the-fly exporter available? Needs @sap/cds-dk >= 3.3.0
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else if (cds.compile.to.openapi) {
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debug && debug ('Compiling Open API spec for', service.name)
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cache[service.name] = cds.compile.to.openapi (service.model, {
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service: service.name,
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'openapi:url': service.path,
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'openapi:diagram': true
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})
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}
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}
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return cache[service.name]
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}
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async function openApiFromFile(service) {
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const fileName = resolve(`srv/${service.name}.openapi3.json`)
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const file = await readFile(fileName).catch(()=>{/*no such file*/})
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if (file) {
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debug && debug ('Using Open API spec from file', fileName)
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return JSON.parse(file)
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}
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}
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function addLinkToIndexHtml(service, apiPath) {
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const provider = (entity) => {
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if (entity) return // avoid link on entity level, looks too messy
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return { href:apiPath, name:'Swagger UI', title:'Show in Swagger UI' }
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}
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// Needs @sap/cds >= 4.4.0
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service.$linkProviders ? service.$linkProviders.push(provider) : service.$linkProviders = [provider]
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}
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module.exports = cds.server
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