Skip to content
Search

    CDS Design Time APIs

    This guide is about consuming CDS design-time APIs programmatically.

    Import @sap/cds-dk

    The design-time APIs are provided with package @sap/cds-dk and can be used as follows:

    1. Install it locally:
      npm add @sap/cds-dk
      
    2. Import it in Node.js:
      const cds = require('@sap/cds-dk')
      

    cds.import (file, options) csn

    As an application developer, you have the option to convert OData specification (EDMX / XML), or OpenAPI specification (JSON) files to CSN from JavaScript API as an alternative to the cds import command.

    cds.import is available in the CDS development tool kit version 4.3.1 onwards .

    The API signature looks like this:

    const csn = await cds.import(file, options)
    
    Arguments:
    • file — Specify the path to a single input file to be converted for CSN.
    • optionscds.import() support the following options:

    options.keepNamespace

    This option is only applicable for OData conversion.

    Value Description
    true Keep the original namespace from the EDMX content.
    false Take the filename as namespace.

    If the option is not defined, then the CSN is generated with the namespace defined as EDMX filename.

    options.includeNamespaces

    This option is only applicable for OData conversion.
    It accepts a list of namespaces whose attributes are to be retained in the CSN / CDS file. To include all the namespaces present in the EDMX pass “*”.

    For OData V2 EDMX attributes with the namespace “sap” & “m” are captured by default.

    cds.import.from.edmx (file, options) csn

    This API can be used to convert the OData specification file (EDMX / XML) into CSN. The API signature looks like this:

    const csn = await cds.import.from.edmx(ODATA_EDMX_file, options)
    


    cds.import.from.openapi (file) csn

    This API can be used to convert the OpenAPI specification file (JSON) into CSN. The API signature looks like this:

    const csn = await cds.import.from.openapi(OpenAPI_JSON_file)
    


    Example:

    const cds = require('@sap/cds-dk')
    module.exports = async (srv) => {
      const csns = await Promise.all([
        // for odata
        cds.import('./odata_sample.edmx', { includeNamespaces: 'sap,c4c', keepNamespace: true }),
        // for openapi
        cds.import('./openapi_sample.json'),
        // for odata
        cds.import.from.edmx('./odata_sample.xml', { includeNamespaces: '*', keepNamespace: false }),
        // for openapi
        cds.import.from.openapi('./openapi_sample.json')
      ]);
    
      for (let i = 0; i < csns.length; i++) {
        let json = cds.compile.to.json (csns[i])
        console.log (json)
      }
    }
    

    Special Type Mappings

    The following mapping is used during the import of an external service API, see Using Services. In addition, the Mapping of CDS Types shows import-related mappings.

    OData CDS Type
    Edm.Single cds.Double + @odata.Type: 'Edm.Single'
    Edm.Byte cds.Integer + @odata.Type: 'Edm.Byte'
    Edm.SByte cds.Integer + @odata.Type: 'Edm.SByte'
    Edm.Stream cds.LargeBinary + @odata.Type: 'Edm.Stream'
    Edm.DateTimeOffset
    Precision : Microsecond
    cds.Timestamp + @odata.Type:'Edm.DateTimeOffset' + @odata.Precision:<>
    Edm.DateTimeOffset
    Precision : Second
    cds.DateTime + @odata.Type:'Edm.DateTimeOffset' + @odata.Precision:0
    Edm.DateTime
    Precision : Microsecond
    1
    cds.Timestamp + @odata.Type:'Edm.DateTime' + @odata.Precision:<>
    Edm.DateTime
    Precision : Second
    1
    cds.DateTime + @odata.Type:'Edm.DateTime' + @odata.Precision:0

    1 only OData V2