POP Method (DATASET)

10.8, PLBCMP GUI Only

The Pop method retrieves data items from the DATASET stack. By default, this method retrieves the last data item Push on the DATASET stack in a LIFO (Last In First Out) mode. This default behavior can be changed to use a FIFO (First In First Out) mode by using the {flags} parameter. Once the Pop method executes the data item is automatically deleted from the DATASET. This method uses the following format:

Where:

label

Optional. A Program Execution Label.

object

Required. A DATASET object to which a data item is being added.

return

Optional. A Character String Variable that returns the data string for the data item. Otherwise, an error string formatted as "$ERROR$=errorinfo" is returned.

flags

Optional. A Numeric Variable, decimal number, or Numeric expression that defines a bit mask value that is used to control Pop method behaviors.

Flags Affected: EOS, OVER, ZERO

Notes:

1. The EOS flag is set if the returned data is truncated because the {return} variable is too small.

2. The ZERO flag is always set TRUE.

3. The OVER flag is always cleared.

4. The {flags} bit mask values found in plbmeth.inc are definedfor future usage as follows:

 

Equate	Value	Description
$DSF_POP_FIFO	0x00000001	Use FIFO mode for Pop method.
$DSF_POP_GET_KEY_AND_DATA	0x00000002	Return both the key string followed by a comma which is followed with all of the data being returned.

 

5. When this method generates an error, the {return} variable contains the error string formatted as follows:

 

$ERROR$=nnn

                

Where the 'nnn' error value as follows:

 

Error Code	Description
1	The DATASET is empty.
10	The item data size is too large for DATASET output buffer! Sunbelt internal error.

 

See Also: Method Syntax, DATASET Methods