1. A computer-implemented method for creating an object for data access, the method comprising: receiving user input object-oriented source code in a code editor of a graphical user interface of a development tool; creating a function-expression with the object-oriented source code as an object method that includes an indication that the function-expression should be displayed in a graphical user interface of a development tool; displaying the defined function-expression in a list of available fields for data access in the graphical user interface of the development tool used to create the object; receiving a selection of a field among a list of available fields for data access; creating the object for data access based on the selection; and saving the object for data access in a metadata store.