TEXT TO BLOB

version 11 (Modified)

TEXT TO BLOB (text; blob; textFormat{; offset | *})

The TEXT TO BLOB command writes the Text value text into the BLOB blob.

The textFormat parameter fixes the internal format and the character set of the text value to be written. In databases created beginning with version 11, 4D uses the Unicode character set (UTF8) by default for managing text. For the sake of compatibility, this command can be used to "force" conversion using the Mac Roman character set (used in previous versions of 4D). The character set is chosen via the textFormat parameter. To do this, pass one of the following constants (found in the"BLOB" theme) in the textFormat parameter:

Notes:

• The "UTF8" constants can only be used when the application runs in Unicode mode.

• The "Mac" constants cannot work with texts greater than 32 KB.

• If you want to work with character sets other than UTF8, use the CONVERT FROM TEXT command.

The following table describes each of these formats:

If you specify the * optional parameter, the Text value is appended to the BLOB; the size of the BLOB is extended accordingly. Using the * optional parameter, you can sequentially store any number of Integer, Long Integer, Real or Text values (see other BLOB commands) in a BLOB, as long as the BLOB fits into memory.

If you do not specify the * optional parameter nor the offset variable parameter, the Text value is stored at the beginning of the BLOB, overriding its previous contents; the size of the BLOB is adjusted accordingly.

If you pass the offset variable parameter, the Text value is written at the offset (starting from zero) within the BLOB. No matter where you write the Text value, the size of the BLOB is, increased according to the location you passed (plus up to the size of the text, if necessary). New allocated bytes, other than the ones you are writing, are initialized to zero.

After the call, the offset variable parameter is returned, incremented by the number of bytes that have been written. Therfore, you can reuse that same variable with another BLOB writing command to write another value.

After executing this code:

   SET BLOB SIZE (vxBlob;0)
   C_TEXT (vtValue)
   vtValue := "Café"  ` Length of vtValue is 4 bytes
   TEXT TO BLOB (vtValue;vxBlob;Mac C string)  ` Size of BLOB becomes 5 bytes
   TEXT TO BLOB (vtValue;vxBlob;Mac Pascal string)  ` Size of BLOB becomes 5 bytes
   TEXT TO BLOB (vtValue;vxBlob;Mac Text with length)  ` Size of BLOB becomes 6 bytes
   TEXT TO BLOB (vtValue;vxBlob;Mac Text without length)  ` Size of BLOB becomes 4 bytes
   TEXT TO BLOB (vtValue;vxBlob;UTF8 C string)  ` Size of BLOB becomes  6 bytes
   TEXT TO BLOB (vtValue;vxBlob;UTF8 Text with length)  ` Size of BLOB becomes 9 bytes
   TEXT TO BLOB (vtValue;vxBlob;UTF8 Text without length)  ` Size of BLOB becomes 5 bytes

BLOB to integer, BLOB to longint, BLOB to real, BLOB to text, CONVERT FROM TEXT, INTEGER TO BLOB, LONGINT TO BLOB, REAL TO BLOB.