Dear Andrei,
Are you aware of the interface between xotcl and the acs object system?
You might check out the following links:
Some answer to your questions:
- How to fetch sql content into a single object:
xotcl-core defines already for all objects a method db_1row. By using this method, the variables returned by the sql query are set a instance variables in the used object.
Example (try it e.g. in the developer support in the ds/shell):
Object o
o db_1row . {select * from acs_objects where object_id = 0}
o set title
- How to output variables easy in adp-files:
Well, adp is defined to work within a single namespace. So it has no predefined support for xotcl instance variables. However, it is not very complicated to extend the adp-compiler to recognize it. This way, one could resolve instance variables in ADP similarly to array variables with the syntax @table.entry@ e.g. with the new syntax @object->instance_variable@. But that is not standard. For now, you have to export the variables to the appropriate scope. For the example above for a single variable one can use
o instvar title
or for all instvars of the object
eval o instvar [o info vars]
- How to fetch multiple tuples into multiple objects:
xotcl-core defines instantiate_objects, which accepts an arbitrary SQL query and returns an ordered composite with the results OrderedComposite.
Example (try it e.g. in the developer support in the ds/shell):
# fetch results into an ordered composite
set s [::xo::db::Object instantiate_objects -sql {select * from acs_objects limit 10}]
# iterate over the ordered composite
foreach x [$s children] { append _ [$x set object_id] \n}
# show result
set _
Hope this helps,
Best regards
-gustaf neumann
