uhlmannm
commented
5 years ago Hi Christoph (@cjohn001 ),
the currently available APIs are optimized for the use by controls. We have the requirement logged to provide more convenient methods for accessing and changing data in controller code. Our backlog item is CPOUI5UISERVICESV3-1315.
As to your first question: You currently need a property binding for changing properties of a context. The sketched way using a relative property binding is correct. However, the property binding still needs to be initialized. The method for this is sap.ui.model.Binding.initialize. There are two disadvantages:
- sap.ui.model.Binding.initialize is protected.
- sap.ui.model.Binding.initialize works asynchronously. A change event is raised when the property binding is ready.
However, at this point in time, there is no other way forward. For practicability reasons, I propose to perform the creation of the property bindings and their initialization after data reading but before the user interaction. This will make handling the asynchronism of sap.ui.model.Binding.initialize much easier.
As to your second question: In my tests it is not required to call v4.ODataListBinding.filter. E.g.
var oListBinding = oModel.bindList("/People",undefined,undefined,undefined,{
$select: ["UserName","FirstName","LastName","Age"]
});
oListBinding.attachChange(function(oEvent){
var aContexts = oListBinding.getContexts(0,Infinity),
// further code
});
oListBinding.getContexts(0,Infinity);
Are there any error messages in the console?
Best regards Mathias.
cjohn001
pksinsik
@uhlmannm
Hello Mathias, I would like to come back on you regarding our discussion about the use of the odata v4 interface from javascript. Reading and creation of new records now seems to work for me. However, since yesterday I am trying to update the values of certain items from javascript. Again a topic I cannot do via binding the model data to ui controls.
So I tried the following to retrieve the contexts of a list of items I would like to change:
This is working as expected. In the updateMealConfigs function below, I obtain the context array as expected.
However, it seems that I can only read from the ODataContext binding an it is not possible to update the values directly via the context. Please correct me if this assumption is wrong, I interpreted this from the documentation and I also found no functions to update certain properties of the retrieved context via its binding. The line with var test1 gives me the expected result and retrieves the correct content. As it seems that the ContextBinding is readonly, I tried to use it to create a PropertyBinding for the relevant attribute ("MealName") and tried to update it via a property binding. Unfortunately, this also does not work. var test2 does not get the relevant value assigned. Hence, already reading of the value does not work. The following setValue line than leads to an error in the debugger:
So I am now wondering what I am doing wrong. Would be great if you could provide an example how to use the api for patch requests. Please also not. I have to change multiple attributes per context at once. So if there is a possibility to update not just a single property via a property binding but rather multiple via a context binding at once, an example for this would be great as well.
var oMealConfigList = oModel.bindList("/MealConfigs", undefined, undefined, undefined,{
$filter: "Weekday ne " + strSelectedWeekday });
This does not work for me. If I do not call oMealConfigList.filter(...) is there than something different required, to initialize the list binding? And what would this be?
Thanks a lot for your help!
Best regards, Christoph