Script execution

Script execution
	Chapter 20. Script instructions

Object command execution instruction

Description

The object command execution instruction is used to execute a specified command of an object.

The object on which the command is to be executed is specified through an object reference which can be:

an attribute
a variable
a constant
a script input argument
a script output argument

Input argument values are transferred to the command through input argument assignments and output argument values are transferred from the command through output argument assignments.

See also the section called “Script execution tail” for information about specific error handling.

Syntax

Table 20.5. Object command execution syntax

Production	Syntax	Links
`object_command_execution_instruction`	`object_reference_selector "." command_id input_assignment_list ? output_assignment_list ? script_execution_tail ?`	the section called “Object command execution instruction”
`object_reference_selector`	`object_reference ( "." attribute_id ) *`
`object_reference`	`-> assignable_object_reference -> constant_id -> input_argument_id`
`assignable_object_reference`	`-> attribute_id -> service_selector "." attribute_id -> variable_id -> output_argument_id`
`input_assignment_list`	`"(" input_assignment ( ";" ? input_assignment ) * ")"`
`output_assignment_list`	`"(" output_assignment ( ";" ? output_assignment ) * ")"` remark: if there are no input arguments assigned then the output argument assignment list must be preceded by `()` to indicate an empty input argument assignment list
`input_assignment`	`( input_argument_id "=" ) ? expression` remark: `input_argument_id =` can only be omitted if the called script has exactly one input argument
`output_assignment`	`assignable_object_reference_selector "=" output_argument_id`
`script_execution_tail`	`on_error_clause ?`	the section called “Script execution tail”
`on_error_clause`	`"on_error" ":" ( "exit_script" \| "continue" )` "remark: default value is `exit_script`

Examples

Example 20.4. Object command execution examples

service instruction_examples

   command object_command_execution_examples
      script

         // create supplier
         const supplier supplier = fa_supplier.co_create ( &
            identifier = 100 &
            name = "Bestsoft" )
            
         // execute object command with 1 output argument
         var string supplier_XML = c_supplier.co_convert_to_XML
         
         // execute object command with 2 input arguments and 1 output argument
         supplier_XML = supplier_XML.co_replace_all ( &
            to_replace = "identifier" &
            replace_by = "id" )
      
         // execute object command with 2 input arguments and 2 output arguments
         var file temporary_file
         var resource_error error
         se_text_file_IO.create_temporary_text_file ( &
            delete_file_on_exit = yes &
            text = supplier_XML ) &
            ( v_temporary_file = o_result &
            v_error = o_error )
         if v_error #r void then
            // error handling
            exit script
         end if


         // if we are just interested in 1 of the 2 output arguments we can also write as follows:
         // (Remark: It is NOT a good idea to ignore the error returned by a command)
         v_temporary_file = se_text_file_IO.create_temporary_text_file.result ( &
            delete_file_on_exit = yes &
            text = supplier_XML )
         if v_temporary_file =r void then
            // error handling
            exit script
         end if

      end script
   end command
   
end service