JSONModel: Make pSequentialImportCompleted public API

[DerGuteWolf]

OpenUI5 version: 1.52/1.56

When defining JSON Models in the manifest.json with a remote URI, it is difficult in a controller to make sure that the data has actually been loaded. When the data has already been loaded when attachRequestCompleted is called, this is never fired.
You have already an internal property pSequentialImportCompleted providing a Promise which would solve this problem. Could you make this Promise officially available?

[RandomByte]

Hi @DerGuteWolf, thanks for bringing this to our attention. We are tracking this internally as 1880574213.

[RandomByte]

Hey @DerGuteWolf,

Could you please provide us with an example (e.g. via https://plnkr.co/) that showcases this problem? That would help us a lot.

Thanks and best regards,
Merlin

[DerGuteWolf]

Hi @RandomByte ,

a public example is a bit difficult. The JSON models we use are the SCP HTML5 userapi and an HANA xsjs JSON service. Both vary in the timing enough, so the attachRequestCompleted for these models sometimes works and sometimes does not work. I will try to make an example with some public JSON services.
Regards,
DerGuteWolf

[DerGuteWolf]

Hi @RandomByte ,
I have now reduced the model and used two public JSON APIs:
https://plnkr.co/edit/EvgR81352zwTmqDpvqdu?p=preview
Be commenting you can try different versions: use attachRequestCompleted for the two models in different sequence, use Promises, use nothing at all to wait for the two models to be ready.
As this depends heavily on the reaction times of the two services you have to try this several times. Most times one of the two attachRequestCompleted will not fire thus you will see nothing. Without waiting the services may be too slow, so you will also see nothing. With promises you will always see both results.
Regards,
DerGuteWolf

[RandomByte]

Thanks, I forwarded this information to the responsible developer. He'll be in contact with you soon.

[DerGuteWolf]

Hi @RandomByte ,
any update for this? I was not contacted by a developer so far...
Regards,
DerGuteWolf

[Thodd]

Hi @DerGuteWolf,

sorry for the late response. We've been working on this and the issue somehow slipped through my fingers lately.

We have a pending commit which will introduce a dataLoaded() function on the JSONModel.
This function will expose the Promise you mentioned, though we need to make some additional refactorings.
We also intent to introduce a Promise as a return value for the loadData calls, so the applications can access the loading state of single data requests as well.

I guess we will merge this in the next days.

Regards,
Thodd

[DerGuteWolf]

Hi @Thodd, thanks for the update. Please make sure, that this also works für models loaded through the manifest. From your description this seems to be possible, however I wanted to draw your attention to this use case, as we have most problems with it.

[Thodd]

Hi again @DerGuteWolf,

The dataLoaded function should solve your issue, when accessing the model after it's creation from the manifest. Internally the JSONModel also calls loadData, which now returns a promise which resolves based on the sent request.

BR,
Thodd