[geeklog-devel] UDFs

[Dwight Trumbower]

This the first proposal for dynamic udfs in geeklog2. I have done something 
similar in the past with other systems. This works better than having a set 
number of udfs in a table. It is easier to retrieve the data because you 
don't have to check all predefined fields You can do a simple SELECT * from 
udfs where scope ="entryscreen", instead of SELECT udf1, udf2, udf3, udf4, 
udf5 from fixedudfs, which you then would have to check which udfs where used.

Take a look the following an poke holes in it.

In order to make things flexible for udfs, it makes sense to have a table 
with unlimited udfs. Here the goal is for flexibility and not readability.

Start with the basic table

Create Table udfs(
         udfid
         name  - field name on ui
         datatype  - could have a lookup table but might need to 
denormalize for performance
         scope - Where it is used, could be global, screen name, form name, 
etc.
         udfvalue - stored data for the udf

You could store the potential values in another table if you wanted to 
dynamically create a list.
  i.e. attributes for a SELECT element

Create table udfattributes
         udfid  - links to the udf table
         name - attribute name, used in list

If you want security at a field level, cross reference table would need to 
be incorporated.

Create Table udfrights
         udfid
         groupid

Fire away.

Dwight
dwight at trumbower.com