remove loaned books from books on shelf - fixes BUG-38

main.py

@@ -951,12 +951,24 @@ def OrderBooks(books):
             ordered_books.append(b)
     return ordered_books
 
+def RemLoans(books):
+    """ Remove any books on loan from list - used for books on shelf view """
+    from main import Book_Loan_Link
+
+    loaned_books=Book_Loan_Link.query.all()
+    for b in loaned_books:
+        for i, item in enumerate(books):
+            if item.id == b.book_id:
+                books.remove(item)
+        
+
 @app.route("/books_on_shelf", methods=["GET"])
 @login_required
 def books_on_shelf():
 
     # start with all books owned sorted by author, then title, but it includes sub-books, so remove them...
     books = Book.query.join(Owned).join(Book_Author_Link).join(Author).filter(Owned.name=='Currently Owned').filter(Book_Author_Link.author_num==1).order_by(Author.surname,Author.firstnames,Book.title).all()
+    RemLoans(books)
     RemSubs(books)
 
     ordered_books=OrderBooks(books)