A blob object is so called because it encapsulates a Binary Large OBject or BLOB. This is a block of data, often quite large, that is stored in a binary form and which is likely to contain many non-printable characters and probably some nulls as well.

You cannot instantiate a blob object directly in JavaScript but you can obtain one by fetching the data from a database as shown in the example code.

Example code:

   <SERVER>

   // Example derived from Wrox Professional JavaScript

   // This opens a database, selects some records

   // Traverses the collection that was selected

   // and for each one, outputs an image tag.

   database.connect("ODBC", "TargetDB", "", "", "");

   myCursor = database.cursor("SELECT * FROM TARGET_TABLE");

   while(myCursor.next())

   {

      myBlob = myCursor.blobData;

      write(myBlob.blobImage("bmp"));

   }

   myCursor.close();

   </SERVER>