59 lines
2.4 KiB
JavaScript
59 lines
2.4 KiB
JavaScript
const cds = require('@sap/cds')
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const log = cds.log('data')
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class DataService extends cds.ApplicationService { init(){
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this.on ('READ', 'Entities', req => {
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const { dataSource } = req.req.query
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const srvPrefixes = cds.db.model.all('service').map(srv => srv.name+'.')
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const dataSourceFilter = dataSource === 'db'
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? e => e['@cds.persistence.skip'] !== true // for DB, excl. entities w/o persistence
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: e => !!srvPrefixes.find(srvName => e.name.startsWith(srvName)) // only entities reachable from a service
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return cds.db.model.all('entity')
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.filter (e => req.data && req.data.name ? e.name === req.data.name : true) // honor name filter from request, if any
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.filter (e => !e.name.startsWith('DRAFT.')) // exclude synthetic stuff
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.filter (e => !e.name.startsWith('DataService.')) // exclude this service
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.filter (dataSourceFilter)
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.sort((e1, e2) => e1.name.localeCompare(e2.name))
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.map(e => {
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const columns = Object.entries(e.elements)
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.filter(([_, el]) => !(el instanceof cds.Association)) // exclude assocs+compositions
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.map(([name, el]) => { return { name, type: el.type, isKey:!!el.key }})
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return { name: e.name, columns }
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})
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})
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this.on ('READ', 'Data', async req => {
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const { entity: entityName, dataSource: dataSourceName } = req.req.query
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if (!entityName) return req.reject(400, `Must provide 'entity' query`)
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const entity = cds.db.model.definitions[entityName]
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if (!entity) return req.reject(404, 'No such entity: ' + entityName)
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const query = SELECT.from(entity)
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query.SELECT.limit = req.query.SELECT.limit // forward $skip / $top
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const dataSource = findDataSource(dataSourceName, entityName)
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const res = await dataSource.run(query)
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return res.map((line) => {
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const record = Object.entries(line).map(([column, data]) => {return {column, data}})
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return { record }
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})
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})
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return super.init()
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}}
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module.exports = { DataService }
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function findDataSource(dataSourceName, entityName) {
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for (let srv of Object.values(cds.services)) { // all connected services
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if (!srv.name) continue // FIXME intermediate/pending in cds.services ?
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if (dataSourceName === srv.name || entityName.startsWith(srv.name+'.')) {
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log._debug && log.debug(`using ${srv.name} as data source`)
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return srv
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}
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}
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return cds.services.db // fallback
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}
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