1 --[[--

2 param.update(

3 record, -- database record to be updated

4 key_and_field_name1, -- name of CGI parameter and record field

5 key_and_field_name2, -- another name of a CGI parameter and record field

6 {

7 key3, -- name of CGI parameter

8 field_name3 -- name of record field

9 }

10 )

11

12 This function can update several fields of a database record using GET/POST request parameters (or internal/exchanged parameters). The type of each parameter is automatically determined by the class of the record (_class:get_colums()[field].type).

13 --]]--

14

15 function param.update(record, mapping_info, ...)

16 if not mapping_info then

17 return

18 end

19 assert(record, "No record given for param.update(...).")

20 assert(record._class, "Record passed to param.update(...) has no _class attribute.")

21 local key, field_name

22 if type(mapping_info) == "string" then

23 key = mapping_info

24 field_name = mapping_info

25 else

26 key = mapping_info[1]

27 field_name = mapping_info[2]

28 end

29 assert(key, "No key given in parameter of param.update(...).")

30 assert(field_name, "No field name given in parameter of param.update(...).")

31 local column_info = record._class:get_columns()[field_name]

32 if not column_info then

33 error('Type of column "' .. field_name .. '" is unknown.')

34 end

35 local new_value = param.get(key, column_info.type)

36 if new_value ~= record[field_name] then

37 record[field_name] = new_value

38 end

39 return param.update(record, ...) -- recursivly process following arguments

40 end