EXPAND BLOB

EXPAND BLOB ( blob )

Parameter	Type		Description
blob	Blob	→	BLOB to expand

Description

The EXPAND BLOB command expands the BLOB blob that was previously compressed using the COMPRESS BLOB command*.*

After the call, the OK variable is set to 1 if the BLOB has been expanded. If the expansion could not be performed, the OK variable is set to 0.

If the expansion could not be performed because of a lack of memory, no error is generated and the method resumes its execution.
In any other case (i.e. the BLOB has not been compressed or is damaged), the error -10600 is generated. This error can be trapped using the ON ERR CALL command.

To check if a BLOB has been compressed, use the BLOB PROPERTIES command.

Example 1

This example tests if the BLOB vxMyBlob is compressed and, if so, expands it:

 BLOB PROPERTIES(vxMyBlob;$vlCompressed;$vlExpandedSize;$vlCurrentSize)
 If($vlCompressed#Is not compressed)
    EXPAND BLOB(vxMyBlob)
 End if

Example 2

This example allows you to select a document and then expand it, if it is compressed:

 $vhDocRef :=Open document("")
 If(OK=1)
    CLOSE DOCUMENT($vhDocRef)
    DOCUMENT TO BLOB(Document;vxBlob)
    If(OK=1)
       BLOB PROPERTIES(vxBlob;$vlCompressed;$vlExpandedSize;$vlCurrentSize)
       If($vlCompressed#Is not compressed)
          EXPAND BLOB(vxBlob)
          If(OK=1)
             BLOB TO DOCUMENT(Document;vxBlob)
          End if
       End if
    End if
 End if

System variables and sets

The OK variable is set to 1 if the BLOB has been successfully expanded, otherwise it is set to 0.

See also

BLOB PROPERTIES
COMPRESS BLOB

Properties

Command number	535
Thread safe	✓
Modifies variables	OK