We can import vocabulary file to enable annotations in ODATA. And the technical object 'Annotation' itself is nothing but some tags (name and value pairs) to be added to the metadata file, if I am right. So the vocabulary file is somehing like template to generate some codes in MPC for these tags? and actually the tags like sap:label is also some kind of annotation. And SAP Gateway like the document is to add some SAP prefix tags to the odata file?
Some of my questions:
1 where in the MPC is for the annotation generation? In debug stack, i can only find get_model(). But it looks there is nothing about annotation generation in it.
2 For all the EntitySet settings in SEGW, all the configuration/setting will be transferred into a metadata xml when client access the service? So it is at runtime, all these entityset/properties will be transformed?
3 And is there any document about how to use the standard annotation vocabulary like /IWBEP/VOC_COMMON? For exmaple, if I imported it, I can go to annotation of each property and create a new instance in ValueSet. And set another EntitySet as a search help. But for other thing, i am not sure how to use it. if I want to map a Dropdown in UI5 and I need to set some annotation like sap:text. I have no idea how to set it with annotation file.