v2.ODataListBinding: Operation Mode "Client" Doesn't Consider Server-side Paging

[boghyon]

URL (minimal example if possible)

https://jsbin.com/tomajef/edit?js,output

Steps to reproduce the problem:

1. Open: https://services.odata.org/V2/Northwind/Northwind.svc/Customers?$format=json
2. See that the service didn't return all entities but appends the property "__next" for the client to get the next batch of entities.
3. Open the minimal example. The sample has the defaultOperationMode: "Client".
4. Observe that the list binding doesn't load this many items.

What is the expected result?

Even with the operation mode "Client", the ODataListBinding (V2 as well as V4*) checks whether there are more entities to fetch ("__next" / "@odata.nextLink").

_{* Currently doesn't support the "Client" operation mode.}

What happens instead?

Client mode ignores server-side paging.

Any other information? (attach screenshot if possible)

Once the line defaultOperationMode: "Client" is removed, you can see that the list binding fetches more and more entities.

However, in the client operation mode, the bLengthFinal is immediately set to true without checking if there is "__next".

openui5/src/sap.ui.core/src/sap/ui/model/odata/v2/ODataListBinding.js

Lines 615 to 627 in 00a454e

	if (that.useClientMode()) {
	// For clients mode, store all keys separately and set length to final
	that.aKeys = [];
	jQuery.each(oData.results, function(i, entry) {
	that.aKeys[i] = that.oModel._getKey(entry);
	});
	that.updateExpandedList(that.aKeys);
	that.aAllKeys = that.aKeys.slice();
	that.iLength = that.aKeys.length;
	that.bLengthFinal = true;
	that.applyFilter();
	that.applySort();
	} else {

[IlianaB]

Hello boghyon,
Thank you for sharing this finding. I've created an internal incident 1870453492. The status of the issue will be updated here in GitHub.

Regards,
Iliana

[svbender]

Hello boghyon,

The v2.ODataListBinding does not support __next links and there are no plans to support them in the near future.

The back-end needs to respond all entries at once in the client mode.

Best regards,
Sven

[ecker]

Hi boghyon, thanks for your input. As has been commented, we recommend the "server" mode for such scenarios and don't expect to enhance the "client" mode for server-side paging.