I have been using SAP Gateway from one month and feel that there is too much of redundancy and Limitations. Let me brief in points :
1) Entity Relationship
ODATA has an obligatory requirement for a Primary Key Relation between in the input and output parameters of the FM......For instance, if there is a INITILIZATION web service created that calls an FM to export 5 tables in the response , the GET ENTITY SET Query executes the FM as many as 5 times to the get the details which could be done with single execution of FM Here each table is addressed as an Entity which is not apt is what I feel...
I had to use ASSOCIATION to get 5 tables and why would anyone do that !
2)Custom Code in the Methods
When it comes to flexibility and altering a code , the custom code written in the methods ( GET , CREATE , DELETE , UPDATE , GET ENTITY SET ) is erased when the user hits a GENERATE button....
3)Redundant Data Returned
There is a set of redundant data that could effect the JSON response size unnecessarily for instance below....why is the metadata is in reponse....can that be avoided.....
"__metadata": {
"id": "/sap/opu/odata/sap/ywebservice/initAhsWebservice('RETURNLINK')",
"uri": "/sap/opu/odata/sap/ywebservice/initAhsWebservice('RETURNLINK')",
"type": "ywebservice.initAhsWebservice"
4)CREATE calls
The POST/CREATE web service does a GET method that calls the FM once more with the same data. This redundant code can be commented out but then the regeneration of the code would get that working again !!!
I want know if am following the right standards or am having half baked knowledge in SAP GATEWAY SERVICES !!!
Please let me know if am going in wrong way all together....