OpenUI5: Where is the data gone, loaded by sap.ui.model.odata.v2.ODataModel()? - odata

Question

I have been googling and testing around for quite a few days with no success. If someone could give me a hint to point me into the right direction, then I would greatly appreciate that.
What is my target: to get some data from an OData service and show it in an UI5 oTable. Later on, I will have to do the CRUD-operations, but for now the aim is just to show the data successfully.
What I have got so far: I have an MVC project. I have created an OpenUI5Controller.cs, whose purpose is to represent an ODataService:
public class OpenUI5Controller : Controller
{
private MyEntities myEntities = new MyEntities();
public JsonResult GetAllContragents()
{
try
{
IQueryable<Contragent> contragents = myEntities.Contragent.OrderBy(x => x.Code);
// for now, take the first 100 only
contragents = contragents.Take(100);
var jsonData = new
{
rows = contragents.ToList()
//rows = "123"
};
var res = Json(jsonData, JsonRequestBehavior.AllowGet);
return res;
}
catch (Exception e)
{
LoggingService.WriteLog("Error in OpenUI5Controller.GetAllContragents()", e);
return null;
}
}
}
After that, I try to consume the data like this:
var oModel = new sap.ui.model.odata.v2.ODataModel('/OpenUI5/GetAllContragents', {
//maxDataServiceVersion: '2.0',
json: true,
skipMetadataAnnotationParsing: true,
// none of those callbacks is ever triggered, even the requestFailed...!?
requestSent: function (a, b, c) {
debugger;
var trgrwg = oModel.getData();
var vfewgvfewgv = oModel.getProperty('/');
var vfewgvfewgv2 = oModel.getProperty('/rows');
var vfewgvfewgv3 = oModel.getProperty('rows');
},
requestFailed: function (a, b, c) {
debugger;
var trgrwg = oModel.getData();
var vfewgvfewgv = oModel.getProperty('/');
var vfewgvfewgv2 = oModel.getProperty('/rows');
var vfewgvfewgv3 = oModel.getProperty('rows');
},
requestCompleted: function (a, b, c) {
debugger;
var trgrwg = oModel.getData();
var vfewgvfewgv = oModel.getProperty('/');
var vfewgvfewgv2 = oModel.getProperty('/rows');
var vfewgvfewgv3 = oModel.getProperty('rows');
},
batchRequestCompleted: function (a, b, c) {
debugger;
var trgrwg = oModel.getData();
var vfewgvfewgv = oModel.getProperty('/');
var vfewgvfewgv2 = oModel.getProperty('/rows');
var vfewgvfewgv3 = oModel.getProperty('rows');
},
useBatch : false
});
var trgrwg = oModel.getData();
var vfewgvfewgv = oModel.getProperty('/');
var vfewgvfewgv2 = oModel.getProperty('/rows');
var vfewgvfewgv3 = oModel.getProperty('rows');
var vfewgvfewgv4 = oModel.getProperty('contragents');
var vfewgvfewgv5 = oModel.getProperty('/contragents');
var vfewgvfewgv6 = oModel.getProperty('Contragents');
var vfewgvfewgv7 = oModel.getProperty('/Contragents');
debugger;
When stopping at this breakpoint, I see this in the Chrome Developer Tools:
Moving further, I came accross this and tried to read() those contragents:
oModel.read('/Contragents', {
success: function (event) {
debugger;
// event.root I guess should be the received data as jsonString
// As I guess, I will have to get it and give it to oModel.oData manually, or am I wrong? I guess this would cause update(), delete()... calls to fail later on. Anyways...
sap.ui.getCore().setModel(oModel); // https://archive.sap.com/discussions/thread/3746588 - seems not to work like this
if (withJsonModel !== true) { https://help.sap.com/saphelp_uiaddon20/helpdata/en/12/32241b99d7437ba3614698d53dfa4b/content.htm
oTable.setModel(oModel);
oTable.bindRows("/");
//oTable.bindRows("/rows");
oTable.placeAt('tblContragents', "only");
}
},
error: function (event) {
debugger;
}
});
Here, neither success, nor error callback gets ever triggered.
After this read() attempt, I have again:
var trgrwg = oModel.getData();
var vfewgvfewgv = oModel.getProperty('/');
var vfewgvfewgv2 = oModel.getProperty('/rows');
var vfewgvfewgv3 = oModel.getProperty('rows');
var vfewgvfewgv4 = oModel.getProperty('contragents');
var vfewgvfewgv5 = oModel.getProperty('/contragents');
var vfewgvfewgv6 = oModel.getProperty('Contragents');
var vfewgvfewgv7 = oModel.getProperty('/Contragents');
and I see this:
After that, I have oTable = new sap.ui.table.Table(...);
Finally, I try this:
sap.ui.getCore().setModel(oModel);
//oTable.setModel(oModel); // or maybe should be this one directly?
oTable.bindRows("/Contragents");
oTable.placeAt('tblContragents', "only");
As a result, I get an empty table.
I suppose I should tell you what I see in Fiddler as well: I see this request: 1 200 HTTP localhost:55714 /OpenUI5/GetAllContragents/$metadata
As a result in the TextView of the response section, I see the data as json, that I need to show in the table.
How to make it work and show the data in the table?
edit from 02.02.2017: I have 1% of progress. After some more and more testing and googling, I decided to try it like this.
First of all, some time ago (can't really remember when), after seeing a good example for OdataServices, I decided to create a dedicated controller like this:
public class ContragentsController : ODataController
{
private MyEntities db = new MyEntities();
//public System.Web.Mvc.JsonResult GetContragents()
public string GetContragents()
{
try
{
IQueryable<Contragent> contragents = db.Contragent.OrderBy(x => x.Code);
// for now, give me first 100
contragents = contragents.Take(100);
var jsSerializer = new System.Web.Script.Serialization.JavaScriptSerializer();
var rows = jsSerializer.Serialize(contragents.ToList());
//var jsonData = new
//{
// rows = model
//};
//var res = new System.Web.Mvc.JsonResult();
//res.Data = jsonData;
//res.JsonRequestBehavior = System.Web.Mvc.JsonRequestBehavior.AllowGet;
return rows;
}
catch (Exception e)
{
//...some errorLogging
return null;
}
}
After that, I changed the call to ODataModel() like this:
var oModel = new sap.ui.model.odata.v2.ODataModel(BASE_HREF + 'odata/', {
//maxDataServiceVersion: '2.0',
json: true,
skipMetadataAnnotationParsing: true,
// those callbacks still do not get called at all
requestSent: function (a, b, c) {
debugger;
var trgrwg = oModel.getData();
var vfewgvfewgv = oModel.getProperty('/');
var vfewgvfewgv2 = oModel.getProperty('/rows');
var vfewgvfewgv3 = oModel.getProperty('rows');
},
requestFailed: function (a, b, c) {
debugger;
var trgrwg = oModel.getData();
var vfewgvfewgv = oModel.getProperty('/');
var vfewgvfewgv2 = oModel.getProperty('/rows');
var vfewgvfewgv3 = oModel.getProperty('rows');
},
requestCompleted: function (a, b, c) {
debugger;
var trgrwg = oModel.getData();
var vfewgvfewgv = oModel.getProperty('/');
var vfewgvfewgv2 = oModel.getProperty('/rows');
var vfewgvfewgv3 = oModel.getProperty('rows');
},
batchRequestCompleted: function (a, b, c) {
debugger;
var trgrwg = oModel.getData();
var vfewgvfewgv = oModel.getProperty('/');
var vfewgvfewgv2 = oModel.getProperty('/rows');
var vfewgvfewgv3 = oModel.getProperty('rows');
},
useBatch : false
});
The whole drama is that SapUI5 runs a request for $metadata, before making the actual request to odata/Contragents and so on. As expected in this case, I see in Fiddler, that the server 404-s to that request: http://localhost:55714/odata/Contragents/$metadata and it doesn't reach the moment to make the request to Contragents. I know, that I will have to change the source of the library somewhere in order to prevent this $metadata request from running, which I don't want to do. So in Fiddler's Composer, I tried the following: localhost:55714/odata/$metadata and it returned some xml with the desired metadata (maybe indeed it is important, but I haven't understood yet why). Next step was to modify the call to sap.ui.model.odata.v2.ODataModel(); as shown above. The great thing after all that is the fact, that oModel.read('/Contragents', {...}); showed signs of life! Now, the success callback gets called and in event.root I get those contragents as json string. And then what? I tried oModel.setData(JSON.parse(event.root)); but it gave me this error:
Also, if I manage to get it working this way, I don't quite understand, will the CRUD methods of oModel work? oModel.setData()-ing is something familliar to me from the time when I was playing around with JSONModel():
oModel = new sap.ui.model.json.JSONModel();
oModel.setData(dataForGrid); // this works like a charm
But using JSONModel() means, that I cannot use the insert(), update()... methods of sap.ui.model.odata.v2.ODataModel(), because JSONModel(); does not provide us with them, which is normal, as long as I get dataForGrid via a standard $.ajax() call.
edit2: While debugging, I noticed, that the method ContragentsController.GetContragents(); gets called twice and in the console, I see this error message:
edit3: Following the good example for ODataService, I added a "selection" method to the controller like this:
// GET: odata/Contragents(5)
[EnableQuery]
public SingleResult<Contragent> GetContragents([FromODataUri] string key)
{
return SingleResult.Create(db.Contragent.Where(contragent => contragent.Code == key));
}
In Fiddler, it 404-s and does not get called at all no matter if i Compose it like this: http://localhost:55714/Contragents(2) or like this: http://localhost:55714/odata/Contragents(2)
Couple of minutes later, I've got couple of % progress. I looked even closer in the tutorial and I noticed something, which made me change the "selection" method to this:
// GET: odata/Contragents(5)
[EnableQuery]
public SingleResult<Contragent> Get([FromODataUri] string key)
{
return SingleResult.Create(db.Contragent.Where(contragent => contragent.Code == key));
}
Now, when I Compose this request: http://localhost:55714/odata/Contragents(2), it now does not 404, but does 406 Not Acceptable. I came across this error code some time ago and I didn't understand well what is the reason for it and how is it related to ODataServices.
I just reminded myself what does 406 mean and it turns out, that every method on the controller must return a json result as string. Because, SapUI5 sets Accept-Type to "application/json".