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Use the OData v4 Type-safe Client API

This guide explains how to use features of the OData v4 protocol supported by the SAP Cloud SDK. We will use People service from OData v4 tutorial and Business Partner Service from the SAP S/4HANA ERP suit.

note

For more details on how to execute requests using a OData type-safe client by the SAP Cloud SDK, refer to this guide.

Entities

In OData, entity collections are the resource against which you execute requests and CRUD operations. The SAP Cloud SDK operates on entity classes, that represent those resources.

An OData JSON representation of a single business partner could be something like this:

{
"FirstName": "Peter",
"LastName": "Pan",
"to_BusinessPartnerAddress": [
{
"Country": "Neverland"
}
]
}

When using the SAP Cloud SDK this entity would be represented as an instance of the BusinessPartner entity class from the according business partner service. The properties of entity class instances are held in camel case as is common in JavaScript:

BusinessPartner {
firstName: 'Peter',
lastName: 'Pan',
toBusinessPartnerAddress: [ BusinessPartnerAddress { country: 'Neverland' } ]
}

OData responses, that contain entities are automatically deserialized to the respective entity class when using the SAP Cloud SDK. To execute create or update requests you have to build an instance of an entity class, that represents the data to be created or updated. There are three ways to build entities on your own as described below.

Custom Fields

In the real world, OData service implementations can differ from their original service specifications. This can happen due to incorrect specifications or customizations of the service. The SAP Cloud SDK supports custom fields on your entities, that are not covered by the specification the according service is based on.

You can set custom fields on an entity through the .setCustomFields and .setCustomField methods. Setting custom fields with existing keys overrides the existing fields. Non-existent fields are added without removing other fields.

// add custom fields to the existing fields
businessPartner.setCustomFields({
myCustomField: 'this is custom'
});

// add specific custom field
businessPartner.setCustomField('myCustomField', 'this is custom');

You can also access existing fields using the .getCustomField and .getCustomFields methods.

// get all custom fields
const customFields = businessPartner.getCustomFields(); // { myCustomField: 'this is custom' }

// get specific custom field
const customFields: = businessPartner.getCustomField(); // 'this is custom'
Custom fields are not serialized or deserialized

As custom fields are not defined through the service specification, the type of their values is unknown. Therefore, custom fields are never automatically serialized or deserialized. If you are using custom fields, you might have to take care of serialization on your own.

Build an Entity From Scratch

In version 2.0 of the SAP Cloud SDK, two new changes have been introduced:

  • an API class for each entity (e.g. BusinessPartnerApi), providing access to its properties via a schema, and
  • a common method, e.g. businessPartnerService, with accessors for all the API classes.

To build an entity by assigning its properties, use the entity builders provided by the API class. First invoke the .entityBuilder method to access the builder, then you can set the properties and finally call the .build method to yield the entity. To set navigation properties that link to other entities, you have to create the linked entities using their respective builders. Navigation properties that are linked through a one-to-many relation, are set by passing an array (even if that array only contains one entity). One-to-one relations are assigned as objects. The example below shows how you can create the data from above using the entity builder. The relation to the business partner address is a one-to-many relation here.

import { businessPartnerService } from '@sap/cloud-sdk-vdm-business-partner-service';

const { businessPartnerApi, businessPartnerAddressApi } =
businessPartnerService();
businessPartnerApi
.entityBuilder()
.firstName('Peter')
.lastName('Pan')
.toBusinessPartnerAddress([
businessPartnerAddressApi.entityBuilder().country('Neverland').build()
])
.build();

You can also add fields, that are unknown according to the specification, if you add them as custom fields. To achieve this, pass an object the .withCustomFields method, where the keys denote the names of the custom fields, and the values their respective values.

import { businessPartnerService } from '@sap/cloud-sdk-vdm-business-partner-service';

const { businessPartnerApi } = businessPartnerService();
businessPartnerApi
.entityBuilder()
.firstName('Peter')
.withCustomFields({
myCustomField: 'this is custom'
})
.build();

Build an Entity From a JSON Representation

Sometimes, it makes sense for you to store your data as a JSON object, that is based on the entity type. For example, when using the property names of the entity class as properties of your object. If you are looking for a way to create an entity from a JSON response, that you got from an OData service, you are probably looking for entity deserialization.

This would be the JSON representation of a business partner in the SAP Cloud SDK:

{
"firstName": "Peter",
"lastName": "Pan",
"toBusinessPartnerAddress": [
{
"country": "Neverland"
}
]
}

You can use this data to build an entity using the .fromJson method. The example below shows how you would create an instance of the business partner class using the .fromJson method.

import { businessPartnerService } from '@sap/cloud-sdk-vdm-business-partner-service';

const { businessPartnerApi } = businessPartnerService();
const businessPartner = businessPartnerApi.entityBuilder().fromJson({
firstName: 'Peter',
lastName: 'Pan',
toBusinessPartnerAddress: [
{
country: 'Neverland'
}
]
});

If there are unknown fields present in the JSON object, they will be treated as custom fields.

Deserialize an OData JSON Response to an Entity

In some cases you might retrieve raw data from an OData response. If you need to transform it to an SAP Cloud SDK representation of an entity, you can deserialize it using the deserializeEntity function. Fields unknown according to the specification are added as custom fields, without deserializing the according value. Note that this function is not part of a specific service and has to be imported from the SAP Cloud SDK core package.

import { deserializeEntity } from '@sap-cloud-sdk/odata-v2';

const businessPartner = deserializeEntity(
{
FirstName: 'Peter',
LastName: 'Pan',
to_BusinessPartnerAddress: [
{
Country: 'Neverland'
}
]
},
BusinessPartner
);

Customize (De-)Serialization

Since version 2 of the SAP Cloud SDK you can customize how the data you get from a service is deserialized and serialize when sending it back to the service.

To influence (de-)serialization you have to provide your custom (de-)serializers to a service.

A (de-)serializer is an object of type DeSerializer that defines the following callback functions:

  • deserialize: Takes a value as given by the service and returns a deserialized value, i.e. its represenation in code.
  • serialize: Takes a deserialized value and transforms it to the format and type expected by the service.
  • serializeToUri (optional): For some EDM types the serialized format differs between values in a payload and URI. This function takes a deserialized value and transforms it to a string with the format expected by the service for URIs. The second parameter of this callback function references the serialize function, which can optionally be used as a basis for URI serialization. If this function is not specified, the URI serialization defaults to the serialize function.

The type DeSerializer has one generic parameter, that represents the deserialized type.

Example:

const doubleDeSerializer: DeSerializer<number> = {
deserialize: (val: string) => Number(val),
serialize: (val: number) => val.toString(),
serializeToUri: (value, serialize) => `${serialize(value)}D`
};

The example above shows a simplified version of the SAP Cloud SDK default (de-)serializer for the EDM type Edm.Double. The deserialize function converts the raw value to a number. The serialize function converts the deserialized value to a string. The serializeToUri function makes use of the serialize function and appends a "D" at the end of the string.

To specify custom (de-)serializers for a service, you have to pass an object to the service function, that maps from EDM type(s) to your custom (de-)serializer. All unspecified EDM types are still (de-)serialized using the SAP Cloud SDK defaults.

Example, using the above doubleDeSerializer for the business partner service:

const customDeSerializers = { 'Edm.Double': doubleDeSerializer };
const { businessPartnerApi } = businessPartnerService(customDeSerializers);

All requests against the businessPartnerApi will now use the custom (de-)serializers for "Edm.Double" and the default (de-)serializers for all other EDM types.

Using (De-)Serializers for Temporal

The SAP Cloud SDK currently uses Moment.js to handle dates and time. Moment.js makes up a major portion of the SAP Cloud SDK's dependencies and it is not actively developed anymore. We did't want to replace Moment.js with another library, but rather use the capabilities of the JavaScript language. Temporal is a stage 3 proposal for a date/time API in ECMAScript. At the time, there is polyfill available, but it is not recommended for productive use. Once it is recommended for productive use, the SAP Cloud SDK will adapt it as a default. However, for non-productive use cases, you can exchange the default date/time handling with Temporal-based (de-)serializers as of today. For this we provide the Temporal-based (de-)serializers as a separate npm package, @sap-cloud-sdk/temporal-de-serializers.

Adapt your code to use this package, for example:

import { temporalDeSerializersV2 } from '@sap-cloud-sdk/temporal-de-serializers';
const { businessPartnerApi } = businessPartnerService(temporalDeSerializersV2);

businessPartnerApi
.entityBuilder()
.organizationFoundationDate(
Temporal.PlainDateTime.from('1995-12-07T03:24:30')
)
.build();

GetAll Request Builder

The GetAll request builder allows you to create a request to retrieve all entities that match the request configuration.

const { businessPartnerApi } = businessPartnerService();
businessPartnerApi.requestBuilder().getAll();

The example above creates a request to get all BusinessPartner entities.

Select

When reading entities, the API offers select( ... ) on the builders. Note that for OData v4 a select does not automatically expand navigation properties. See here for details on select and expand. For non-navigational property the select behaves as follows:

const { businessPartnerApi } = businessPartnerService();
businessPartnerApi
.requestBuilder()
.getAll()
.select(
businessPartnerApi.schema.FIRST_NAME,
businessPartnerApi.schema.LAST_NAME
)
.execute(destination);

The above translates to the following query parameters:

$select=FirstName,LastName

Filter

When operating on a collection of entities, the API offers filter( ... ) on the builders. It directly corresponds to the $filter parameter of the request.

Filters are built via the fields available on the schema property of the entities API class:

/*
Get all business partners that either:
- Have first name 'Alice' but not last name 'Bob'
- Or have first name 'Mallory'
*/
const { businessPartnerApi } = businessPartnerService();
businessPartnerApi
.requestBuilder()
.getAll()
.filter(
or(
and(
businessPartnerApi.schema.FIRST_NAME.equals('Alice'),
businessPartnerApi.schema.LAST_NAME.notEquals('Bob')
),
businessPartnerApi.schema.FIRST_NAME.equals('Mallory')
)
)
.execute(destination);

The EDM primitive types support all six comparison operators:

  • lessThan()
  • lessOrEqual()
  • equals()
  • notEquals()
  • greaterOrEqual()
  • greaterThan()

The example above will translate to this filter parameter:

$filter=(((FirstName eq 'Alice') and (LastName ne 'Bob')) or (FirstName eq 'Mallory'))

Take note of the order of and and or. As or is invoked on the result of and it will form the outer expression while and is an inner expression in the first branch of or.

In addition, the negation operator not can also be used for wrapping any filter expressions.

/*
Get all business partners that do not match any of the cases:
- Have first name 'Alice'
- Have last name 'Bob'
*/
.filter(
not(
or(
businessPartnerApi.schema.FIRST_NAME.equals('Alice'),
businessPartnerApi.schema.LAST_NAME.equals('Bob')
)
)
)

The $filter parameter will then be generated like below:

$filter=not (FirstName eq 'Alice') or (LastName eq 'Bob'))

It is also possible to pass multiple filters to the same filter function without concatenating them with and or or. They will be concatenated with and by default. The two following examples are equal:

.filter(
and(
businessPartnerApi.schema.FIRST_NAME.equals('Alice'),
businessPartnerApi.schema.LAST_NAME.notEquals('Bob')
)
)

The example above can be shortened to:

.filter(
businessPartnerApi.schema.FIRST_NAME.equals('Alice'),
businessPartnerApi.schema.LAST_NAME.notEquals('Bob')
)

Filter on One-to-One Navigation Properties

In addition to basic properties, filters can also be applied on one-to-one navigation properties. The example below shows how to filter on the TO_CUSTOMER, which is a one-to-one navigation property of the BusinessPartner entity. Please note, the CUSTOMER_NAME and CUSTOMER_ACCOUNT_GROUP are properties of the entity Customer, which is the type of the one-to-one navigation property TO_CUSTOMER.

/*
Get all business partners that match all the following conditions:
- Have customer with the customer name 'John'
- Have customer with the customer account group '0001'
*/
.filter(
businessPartnerApi.schema.TO_CUSTOMER.filter(
customerApi.schema.CUSTOMER_NAME.equals('John'),
customerApi.schema.CUSTOMER_ACCOUNT_GROUP.equals('0001')
)
)

The generated $filter will be:

$filter=((to_Customer/CustomerName eq 'John' and to_Customer/CustomerAccountGroup  eq '0001'))

Filter on One-to-Many Navigation Properties

OData V4 introduces lambda operators e.g., any/all, so that the root property of the one-to-many navigation properties can be filtered. Below is an example that demonstrates how to use the lambda operator any.

/*
Get all people that have at least one friend that matches all the following conditions:
- Has first name 'John'
- Has last name 'Miller'
*/
.filter(
any(
peopleApi.schema.FRIENDS.filter(
peopleApi.schema.FIRST_NAME.equals('John'),
peopleApi.schema.LAST_NAME.equals('Miller')
)
)
)

The generated $filter parameter of the URL will be:

$filter=(/any(a0:((a0/Friends/FirstName eq 'John' and a0/Friends/LastName eq 'Miller'))))

More Filter Expressions

More advanced filter expressions can be found here.

Expand

Expand and Select

In contrast to the OData v2 implementation, you have to select and expand separately. In other words selected properties are not expanded automatically as in v2.

The reason for this difference originates in the way select and expand work in OData v4. In OData v4 you select within the expand-argument $expand=Friends($select=FirstName) whereas in OData v2 you select via a path $select=Friends/FirstName&$expand=Friends. That's why we mimic this behavior for select and expand operations in our API for OData v4 type-safe client.

const { peopleApi } = peopleService();
peopleApi
.requestBuilder()
.getAll()
.select(peopleApi.schema.LAST_NAME)
.expand(
peopleApi.schema.FRIENDS.select(
peopleApi.schema.FIRST_NAME,
peopleApi.schema.ADDRESS_INFO
)
);

In the example above you select the LAST_NAME of the root entity and expand the navigation property FRIENDS. In the expanded entity the selected fields are FIRST_NAME and ADDRESS_INFO.

The generated URL for this request will be:

/People?$select=LastName&$expand=Friends($select=FirstName,AddressInfo)

If no select is given, all non-navigational properties are included in the response.

Sub-Queries in Expand

Note that you can create very complex queries within the expand scope:

const { peopleApi } = peopleService();
peopleApi
.requestBuilder()
.getAll()
.expand(
peopleApi.schema.FRIENDS.select(
peopleApi.schema.FIRST_NAME,
peopleApi.schema.ADDRESS_INFO
)
.filter(peopleApi.schema.LAST_NAME.equals('Miller'))
.orderBy(asc(peopleApi.schema.GENDER))
.top(1)
.skip(1)
);

In this example, the filter will reduce the friends to be shown. The effect of a filter depends on whether it is used inside or outside an expand. The different cases are explained in Filters in Expand.

The URL for the query will be:

/People?$expand=Friends($select=FirstName,AddressInfo;$filter=(LastName eq 'Miller');$skip=1;$top=1;$orderby=Gender asc)

Filter Parent vs Filter Children

Depending on the context of the filter it will either filter the parent or the children. In our example, we have a PERSON related to zero to N FRIENDS which are both of type people.

If you want to get all people with first name John the query is:

const { peopleApi } = peopleService();
peopleApi
.requestBuilder()
.getAll()
.filter(peopleApi.schema.FIRST_NAME.equals('John'));

If you want to get all people who have at least one friend with first name John the query is:

const { peopleApi } = peopleService();
peopleApi
.requestBuilder()
.getAll()
.filter(
peopleApi.schema.FRIENDS.filter(
any(peopleApi.schema.FIRST_NAME.equals('John'))
)
);

The lambda all would enforce that all friends must have the first name John. The two queries above filter the parent entity person.

In case you want to get all people but reduce the friends in the response, the filter has to be inside the expand:

const { peopleApi } = peopleService();
peopleApi
.requestBuilder()
.getAll()
.expand(
peopleApi.schema.FRIENDS.filter(peopleApi.schema.FIRST_NAME.equals('John'))
);

This will return all people but only the friends with the first name John will be included in the response.

Skip

skip allows you to skip a number of results in the requested set. It can be useful for paging:

const { businessPartnerApi } = businessPartnerService();
businessPartnerApi.requestBuilder().getAll().skip(10);

Top

top limits the number of returned results. This can also be useful for paging:

const { businessPartnerApi } = businessPartnerService();
businessPartnerApi.requestBuilder().getAll().top(10);

The example above retrieves the first ten BusinessPartner entities.

Count

The method count() allows you to get the number of elements in a collection. It is only available for getAll() requests and is added before the request execution:

const { businessPartnerApi } = businessPartnerService();
businessPartnerApi.requestBuilder().getAll().count();

The return type of count requests is a Promise<number>. You can combine the count() with filter conditions. To get the number of business partners with first name John execute the following request:

const { businessPartnerApi } = businessPartnerService();
businessPartnerApi
.requestBuilder()
.filter(businessPartnerApi.schema.FIRST_NAME.equals('John'))
.count()
.getAll();

As defined in the OData spec count is not affected by top, skip, and orderBy.

top() and skip() are ignored for count

If you include these methods in a count request they will be ignored by the SAP Cloud SDK. These three requests will all return the same value.

BusinessPartner.requestBuilder().getAll().top(5).count();
BusinessPartner.requestBuilder().getAll().skip(5).count();
BusinessPartner.requestBuilder().getAll().count();
Using count within a filter is not supported

Note that we currently do not support the usage of count within a filter condition as described in the OData v4 specification.

GetByKey Request Builder

The GetByKey request builder allows you to create a request to retrieve one entity based on its key:

const { businessPartnerApi } = businessPartnerService();
businessPartnerApi.requestBuilder().getByKey('id');

The example above retrieves the BusinessPartner with the ID 'id'.

The result can be restricted by applying the select function, same as in the GetAll request.

Create Request Builder

The Create request builder allows you to send a POST request to create a new entity:

const { businessPartnerApi } = businessPartnerService();
const businessPartner = businessPartnerApi.entityBuilder().build();
businessPartnerApi.requestBuilder().create(businessPartner);

In the example above we created an instance of BusinessPartner and sent it to the BusinessPartner service in a POST request.

Deep Create

It is also possible to create an entity together with related entities in a single request:

// build a business partner instance with one linked address
const { businessPartnerApi, businessPartnerAddressApi } =
businessPartnerService();
const businessPartner = businessPartnerApi
.entityBuilder()
.firstName('John')
.lastName('Doe')
.businessPartnerCategory('1')
.toBusinessPartnerAddress([
businessPartnerAddressApi
.entityBuilder()
.country('DE')
.postalCode('14469')
.cityName('Potsdam')
.streetName('Konrad-Zuse-Ring')
.houseNumber('10')
.build()
])
.build();

// execute the create request
businessPartnerApi
.requestBuilder()
.create(businessPartner)
.execute(myDestination);
Troubleshooting

When you try the example code above for testing the deep create feature, you might see some errors like "operation module BUA_CHECK_ADDRESS_VALIDITY_ALL; a check table is missing". Typically, it can happen if you are using a new system with a default configuration. You need to configure an address usage field as shown in the example below to fix it.

const { businessPartnerApi, businessPartnerAddressApi, buPaAddressUsageApi } =
businessPartnerService();
businessPartnerApi
.entityBuilder()
.firstName('John')
.lastName('Doe')
.businessPartnerCategory('1')
.toBusinessPartnerAddress([
businessPartnerAddressApi
.entityBuilder()
.country('DE')
.postalCode('14469')
.cityName('Potsdam')
.streetName('Konrad-Zuse-Ring')
.houseNumber('10')
// additional code starts
.toAddressUsage([
buPaAddressUsageApi.entityBuilder().addressUsage('XXDEFAULT').build()
])
.build()
])
.build();

You can also create an entity asChildOf another entity.

Create as Child Of

Assume you have already created a business partner and would like to add a new address to it:

const { businessPartnerApi, businessPartnerAddressApi } =
businessPartnerService();
const existingBusinessPartner = await businessPartnerApi
.requestBuilder()
.getByKey(myID)
.execute(myDestination);

const newAddress = businessPartnerAddressApi
.entityBuilder()
.country('DE')
.postalCode('14469')
.cityName('Potsdam')
.streetName('Konrad-Zuse-Ring')
.houseNumber('10')
.build();

This can be done by using the asChildOf method which allows for creating an entity as a child of an existing entity. You need to give the parent object and the field connecting the two entities:

businessPartnerAddressApi
.requestBuilder()
.create(newAddress)
.asChildOf(
existingBusinessPartner,
businessPartnerApi.schema.TO_BUSINESS_PARTNER_ADDRESS
)
.execute(myDestination);

Update Request Builder

The Update request builder allows you to send PUT or PATCH requests. By default, PATCH is used to only update the changed fields:

const { businessPartnerApi } = businessPartnerService();
businessPartnerApi.requestBuilder().update(businessPartner);

In the example above only the changed fields of the given businessPartner instance are sent to the BusinessPartner service using PATCH.

To update the whole entity use replaceWholeEntityWithPut:

const { businessPartnerApi } = businessPartnerService();
businessPartnerApi
.requestBuilder()
.update(businessPartner)
.replaceWholeEntityWithPut();

This will send a PUT request and thereby replace the whole entity.

Entities can only be updated if ETags match. If you want to force an update of the entity regardless of the ETag configure the request to ignore version identifiers with ignoreVersionIdentifier:

const { businessPartnerApi } = businessPartnerService();
businessPartnerApi
.requestBuilder()
.update(businessPartner)
.ignoreVersionIdentifier();

Delete Request Builder

The Delete request builder allows you to create DELETE requests, that delete an entity.

/*
The following won't work on the real SAP S/4HANA BusinessPartner service because BusinessPartners cannot be deleted.
We added this only for the sake of the example.
*/
const { businessPartnerApi } = businessPartnerService();
businessPartnerApi.requestBuilder().delete(businessPartner);

Entities can only be deleted if ETags match. If you want to force deletion of the entity regardless of the ETag configure the request to ignore version identifiers with ignoreVersionIdentifier:

const { businessPartnerApi } = businessPartnerService();
businessPartnerApi
.requestBuilder()
.delete(businessPartner)
.ignoreVersionIdentifier();

You can also overwrite ETags using setVersionIdentifier:

businessPartnerApi
.requestBuilder()
.delete(businessPartner)
.setVersionIdentifier('etag');

In the example above the ETag 'ETag' is being used instead of the original one.

Entity Builder

In version 2.0 of the SAP Cloud SDK, two new changes have been introduced:

  • an API class for each entity (e.g. BusinessPartnerApi), providing access to its properties via a schema, and
  • a common method, e.g. businessPartnerService, with accessors for all the API classes.

To build an entity by assigning its properties, use the entity builders provided by the API class. First invoke the .entityBuilder method to access the builder, then you can set the properties and finally call the .build method to yield the entity. To set navigation properties that link to other entities, you have to create the linked entities using their respective builders. Navigation properties that are linked through a one-to-many relation, are set by passing an array (even if that array only contains one entity). One-to-one relations are assigned as objects. The example below shows how you can create the data from above using the entity builder. The relation to the business partner address is a one-to-many relation here.

import { businessPartnerService } from '@sap/cloud-sdk-vdm-business-partner-service';

const { businessPartnerApi, businessPartnerAddressApi } =
businessPartnerService();
businessPartnerApi
.entityBuilder()
.firstName('Peter')
.lastName('Pan')
.toBusinessPartnerAddress([
businessPartnerAddressApi.entityBuilder().country('Neverland').build()
])
.build();

You can also add fields, that are unknown according to the specification, if you add them as custom fields. To achieve this, pass an object the .withCustomFields method, where the keys denote the names of the custom fields, and the values their respective values.

import { businessPartnerService } from '@sap/cloud-sdk-vdm-business-partner-service';

const { businessPartnerApi } = businessPartnerService();
businessPartnerApi
.entityBuilder()
.firstName('Peter')
.withCustomFields({
myCustomField: 'this is custom'
})
.build();

Building an Entity From JSON

Sometimes, it makes sense for you to store your data as a JSON object, that is based on the entity type. For example, when using the property names of the entity class as properties of your object. If you are looking for a way to create an entity from a JSON response, that you got from an OData service, you are probably looking for entity deserialization.

This would be the JSON representation of a business partner in the SAP Cloud SDK:

{
"firstName": "Peter",
"lastName": "Pan",
"toBusinessPartnerAddress": [
{
"country": "Neverland"
}
]
}

You can use this data to build an entity using the .fromJson method. The example below shows how you would create an instance of the business partner class using the .fromJson method.

import { businessPartnerService } from '@sap/cloud-sdk-vdm-business-partner-service';

const { businessPartnerApi } = businessPartnerService();
const businessPartner = businessPartnerApi.entityBuilder().fromJson({
firstName: 'Peter',
lastName: 'Pan',
toBusinessPartnerAddress: [
{
country: 'Neverland'
}
]
});

If there are unknown fields present in the JSON object, they will be treated as custom fields.

Handling of ETags

Handling of Cross-Site Request Forgery Tokens

To create, update, and delete requests the SAP Cloud SDK will try to send a CSRF token. Upon execution, the request will try to fetch a token first before issuing the create request. Many services require this behavior for security reasons. However, the create request will be made without a CSRF token if none could be obtained.

Skip CSRF Token Handling

For some services, the CSRF token is not required even for non-get requests. Therefore, skipping fetching the CSRF token makes sense as performance improvement. You can disable the CSRF token request by using skipCsrfTokenFetching() like below:

const { businessPartnerApi } = businessPartnerService();
businessPartnerApi
.requestBuilder()
.update(businessPartner)
.skipCsrfTokenFetching();

Available Filter Expressions

Filter Functions

There are predefined filter functions e.g. length, substring, substringOf in the core library, that allow for a wide range of filter expressions:

/*
Fetch all business partners who have a first name shorter than 5 letters
*/
const { businessPartnerApi } = businessPartnerService();
businessPartnerApi
.requestBuilder()
.getAll()
.filter(length(businessPartnerApi.schema.FIRST_NAME).lessThan(5))
.execute(destination);

For filter functions with boolean as the return type, the filter function can be used directly as a filter without .equal(true). Logically, the two following examples are equivalent to each other:

/*
$filter=startswith(FirstName, 'Bob') eq true
*/
.filter(
startsWith(businessPartnerApi.schema.FIRST_NAME, 'Bob').equal(true)
)

The filter expression can be shortened:

  /*
$filter=startswith(FirstName, 'Bob')
*/
.filter(
startsWith(businessPartnerApi.schema.FIRST_NAME, 'Bob')
)

However, as some services might not support both versions shown above, you might have to choose one of them to fit the target system.

Function Imports

Request Builder

The function import request builder helps build a request for a service operations including their parameters. Not all services expose function imports. We will use the Warehouse Outbound Delivery Order service as an example. The according SAP Cloud SDK for JavaScript package is named @sap/cloud-sdk-vdm-warehouse-outbound-delivery-order-service.

The example below creates a function import request builder for the service operation PostGoodsIssue and then executes it against your destination.

postGoodsIssue({ outboundDeliveryOrder: 'order' }).execute(destination);

The service operation is defined in the service metadata.

If the response structure does not match the transformation type, the promise from execute(destination) will be resolved into undefined.

The default transformer expects the following response format:

{
"d": {
"Count": 0
}
}

Assume the actual response has an additional layer Foo:

{
"d": {
"Foo": {
"Count": 0
}
}
}

In this case, dataAccessor can be used in the following way to modify the response into the desired form for further deserialization.

functionImportRequestBuilder.execute(destination, data => data.d.Foo);

Setting ETag

Function and action imports do not support ETag handling automatically. If your service requires the version identifier of an entity to be present, you can pass it to the request on your own using the addCustomHeaders method (see example below). With this approach, you have to retrieve the required entity with a GET request, before executing the function import. Note, that if the function import execution succeeds, the version identifier of your entity will be outdated.

myFunction()
.addCustomHeaders({ 'if-match': entity.versionIdentifier })
.execute(destination);
Troubleshooting

For some OData function or action imports, the execute() method might be missing as intended. Typically, this might happen when an entity type is shared by multiple entity sets and is used as the return type of OData function or action imports. In such a case you can use executeRaw method for getting the raw response returned after invoking the OData function or action via type-safe API and deserialize it on your own.

Known Issues

  1. Currently, the Entity Type is not supported to be used as the parameters of the function import. Function imports with such unsupported parameters are ignored during the generation. This feature will be implemented in the future. Please check this issue and comment if you need this feature.
  2. Also, for the time being, we only support unbound functions. The bound functions will be supported later, you can create a feature request here.

Action Imports

Similar to the function import mentioned above, the action import request builder has the same structure, so you can build action requests the same way as with the function import.

Troubleshooting

For some OData function or action imports, the execute() method might be missing as intended. Typically, this might happen when an entity type is shared by multiple entity sets and is used as the return type of OData function or action imports. In such a case you can use executeRaw method for getting the raw response returned after invoking the OData function or action via type-safe API and deserialize it on your own.

Known Issues

  1. Similar to the function import, the action import does not support Entity Type as parameters.
  2. Also, we only support unbound actions for now. We plan to support bound actions in the future, please create a feature request here.

Batch Requests

OData batch requests combine multiple operations into one POST operation, allowing you to execute multiple requests with just one network call. This can significantly reduce the network overhead you have to deal with when you want to execute many requests.

Every SAP Cloud SDK client provides a batch function that takes retrieve requests and changesets. You can combine those arbitrarily. To execute batch requests, use the execute method - it works the same way as for single requests.

The response of a batch request is a list of BatchResponses. Each of the items in the response is either a ReadResponse, WriteResponses or an ErrorResponse, see Responses.

Retrieve Request

A retrieve request represents an HTTP GET request. In terms of the SAP Cloud SDK this includes all requests built by GetAllRequestBuilders and GetByKeyRequestBuilders.

You can pass retrieve requests directly to the batch function. Once you execute a batch request you get a list of BatchResponses. A BatchResponse that corresponds with a retrieve request can either be a ReadResponse or an ErrorResponse.

In the example below, we map each given address ID to a GetByKeyRequestBuilder. These retrieve requests are combined into one batch request and executed against a destination.

// Destructure business partner service
const { batch, businessPartnerAddressApi } = businessPartnerService();

async function getAddressesByIds(
businessPartnerId: string,
addressIds: string[]
): Promise<BusinessPartnerAddress[]> {
const retrieveRequests = addressIds.map(addressId =>
// Create get by key request
businessPartnerAddressApi
.requestBuilder()
.getByKey(businessPartnerId, addressId)
);

// Execute batch request combining multiple retrieve requests
const batchResponses = await batch(...retrieveRequests).execute(destination);

// ...
}

Changeset

A changeset is a collection of HTTP POST, PUT, PATCH and DELETE operations - requests built by CreateRequestBuilders, UpdateRequestBuilders, and DeleteRequestBuilders in terms of the SAP Cloud SDK. The order of execution within a changeset is not defined. This differs from the whole batch request itself, where the order is defined. Therefore, the requests within one changeset should not depend on each other. If the execution of any request within a changeset fails, the whole changeset will be reflected as an error in the response. The changeset will not be applied, much like a database transaction.

Unlike retrieve requests, you can not pass change requests to the batch function directly. You have to combine them in a changeset, which in turn can be passed to the batch function. Once a batch request is executed, it returns a list of BatchResponses.

If a changeset was executed successfully, its corresponding response is of type WriteResponses and contains a collection of all raw responses to the requests in the changeset. If the execution fails, the response is an ErrorResponse.

In the example below, we create a list of UpdateRequestBuilders from a list of addresses. We combine these change requests into one changeset and pass it to the batch request, which we execute against a destination.

Once we execute the batch request, we get a list of BatchResponses, which in this example contains one response only, i.e. the one for the changeset.

// Destructure business partner service
const { batch, businessPartnerAddressApi, changeset } =
businessPartnerService();

async function updateAddresses(
businessPartnerAddresses: BusinessPartnerAddress[]
): Promise<BusinessPartnerAddress[]> {
// Create update requests
const updateRequests = businessPartnerAddresses.map(address =>
businessPartnerAddressApi.requestBuilder().update(address)
);

// Execute batch request with one changeset
const batchResponses = await batch(
// Combine update requests into one changeset
changeset(...updateRequests)
).execute(destination);

// Get response for the changeset request
const changesetResponse = batchResponses[0];

// ...
}

Responses

Once a batch request is executed, it returns a list of BatchResponses. The responses correspond to the retrieve requests and changesets in the same order that they were passed to the batch function. Requests that were not successful are reflected as ErrorResponses. Responses to successful requests are represented as ReadResponses for retrieve requests, and WriteResponses for changesets.

To determine the type of a response, you can use the following type guards:
  • .isSuccess() - to check that the response is either a ReadResponse or of type WriteResponses
  • .isError() - to check that the response is an ErrorResponse
  • .isReadResponse() - to check that the response is a ReadResponse
  • .isWriteResponses() - to check that the response is either of type WriteResponses

Then, depending on the corresponding request, you can parse the response or handle the error.

ReadResponse

Successful retrieve requests have the type ReadResponse, which contains the HTTP code, the raw body, and the constructor of the entity that was parsed from the response. To work with an instance of the retrieved entity, you can use the .as method, which allows you to transform the raw data into an instance of an entity represented by the given entity API. Note, that the .as method transforms the raw data to an array of entities, even if the original request was a GetByKeyRequestBuilder.

In the example below, we combine a list of GetByKeyRequestBuilders into one batch request and execute it against a destination. If one of the requests was unsuccessful, an error will be thrown. Otherwise, the responses are transformed into instances of BusinessPartnerAddress.

// Destructure business partner service
const { batch, businessPartnerAddressApi } = businessPartnerService();

async function getAddressesByIds(
...retrieveRequests: GetByKeyRequestBuilder<BusinessPartnerAddress>[]
): Promise<BusinessPartnerAddress[]> {
// Execute batch request combining multiple retrieve requests
const batchResponses = await batch(...retrieveRequests).execute(destination);

// Error handling
if (batchResponses.some(response => !response.isSuccess())) {
throw new Error('Some of the batch subrequests were not successful.');
}

return batchResponses.reduce(
(addresses: BusinessPartnerAddress[], response: BatchResponse) => {
if (response.isReadResponse()) {
// Transform response to an instance of BusinessPartnerAddress
const [address] = response.as(businessPartnerAddressApi);
addresses.push(address);
}
return addresses;
},
[]
);
}

WriteResponses

Successful changeset requests can be cast to WriteResponses which contains all subresponses for the changeset request. Those responses can be accessed by .responses and have the type WriteResponse. Each WriteResponse contains the HTTP code and can contain the raw body and the constructor of the entity that was parsed from the response, depending on whether there was a body in the response. Create and delete requests typically do not have a response body. To work with an instance of an entity given in a WriteResponse, you can use the .as method, which allows you to transform the raw string body into an instance of the given constructor. Note that the response may not exist, so you should only call this method if you know that there is data. Typically the HTTP code is a good indicator for this - 201 No Content probably won't have content. If you are working with TypeScript you will have to tell the compiler, that the .as! method can be used here by adding a !. Also note, that the response to a changeset can be an ErrorResponse. Therefore, it is crucial to check responses for success, before casting them to WriteResponses.

In the example below, we combine a list of UpdateRequestBuilders into one changeset and pass it to the batch request, which we execute against a destination.

Once we execute the batch request, we get a list of BatchResponses, which contains one response only.

If the request was unsuccessful, an error will be thrown. Otherwise, the subresponses are transformed into instances of BusinessPartnerAddress.

// Destructure business partner service
const { batch, businessPartnerAddressApi, changeset } =
businessPartnerService();

async function updateAddresses(
...updateRequests: UpdateRequestBuilder<BusinessPartnerAddress>
): Promise<BusinessPartnerAddress[]> {
// Execute batch request with one changeset
const batchResponses = await batch(
// Combine update requests into one changeset
changeset(...updateRequests)
).execute(destination);

// Get response for the changeset request
const changesetResponse = batchResponses[0];

if (changesetResponse.isWriteResponses()) {
return changesetResponse.responses.map(response =>
// Transform response to an instance of BusinessPartnerAddress
response.as!(BusinessPartnerAddress)
);
}

// Error handling
throw new Error('The changeset request was not successful.');
}

ErrorResponse

Unsuccessful retrieve requests and changesets are reflected as ErrorResponses in the response. Those responses have an httpCode (a number) and a body (a JSON object).

Combining Requests

You can combine requests within a batch request as you like. In the example below, we combine create requests, update requests, and get requests into one batch request. Remember, that change requests have to be wrapped in a changeset. We put the create requests into one changeset and combine the update and delete requests into another. The GET requests are added to the batch request directly without wrapping.

Once the batch request is executed the response will be an array of subresponses to the specific changeset and retrieve requests in the order that was given in the request. Note, that the subresponses of a changeset don't have to be in order.

async function executeComplexBatch(
createAddressRequests: CreateRequestBuilder<BusinessPartnerAddress>[],
updateAddressRequests: UpdateRequestBuilder<BusinessPartnerAddress>[],
deleteAddressRequests: DeleteRequestBuilder<BusinessPartnerAddress>[],
getAddressByIdRequests: GetByKeyRequestBuilder<BusinessPartnerAddress>[]
) {
// Execute batch request
const [
createAddressesResponse,
updateAndDeleteAddressesResponse,
...getAddressesByIdResponses
] = await batch(
changeset(...createAddressRequests),
changeset(...updateAddressRequests, ...deleteAddressRequests),
...getAddressByIdRequests
).execute(destination);

// Do something with responses
}

Serialization

By default, when you execute a batch request, the subrequests are serialized to a multipart representation of the request, which is essentially a string. This is what a create request for a business partner addresses would serialize to:

Content-Type: application/http
Content-Transfer-Encoding: binary

POST /sap/opu/odata/sap/API_BUSINESS_PARTNER/A_BusinessPartnerAddress HTTP/1.1
Content-Type: application/json
Accept: application/json

{"BusinessPartner":"1","PostalCode":"10001","City":"New York","Country":"USA"}

The first lines are request headers for the multipart request, followed by a blank line. The next line contains the request method and URL, followed by the request headers, a blank line, and the request payload. Every "atomic" request is serialized to a string of this kind, while GET and DELETE requests do not provide a payload.

Configure Subrequest Serialization

By default, URLs in the multipart representation of a request are serialized to a path relative to the service, e.g.:

GET /sap/opu/odata/sap/API_BUSINESS_PARTNER/A_BusinessPartnerAddress HTTP/1.1

However, some services might only understand URLs relative to the entity or even absolute URLs.

To configure the serialization of the URLs within a batch request, you can set the subrequest path type with withSubRequestPathType. You can either set it to 'relativeToService', as is the default, 'relativeToEntity', which will yield URLs relative to the entity or 'absolute', which will produce absolute URLs. See below for examples:

Serialize subrequest path relative to entity:

// GET /A_BusinessPartnerAddress HTTP/1.1
batch(...requests).withSubRequestPathType('relativeToEntity');

Serialize subrequest path as absolute URL:

// GET https://my-s4.system.com/sap/opu/odata/sap/API_BUSINESS_PARTNER/A_BusinessPartnerAddress HTTP/1.1
batch(...requests).withSubRequestPathType('absolute');