Search TipsBlob Methods
Blob stands for Binary Large OBjects and are used to store strings over a certain length.
Blob strings provide a database-independent way of storing Cadcorp SIS Desktop items in a database. A Blob string is a string which completely encapsulates a Cadcorp SIS Desktop Item, i.e. its geometry and properties.
TIP: Blob strings in Cadcorp SIS Desktop format are not human readable and may only be interpreted by Cadcorp SIS Desktop.
A GisLink customisation or ActiveX Control application can then be written to create a temporary Point item for each row in the database, get its Spatial Reference and write the Spatial Reference to the new column before deleting the Point item.
The customisation/application could be written to be run as a batch job.
The following methods allow you to access and use SIS items as "Blob" strings.
| CreateItem | Creates an item from a BLOB string. |
| CreateItemB | Creates an item from a BLOB. |
| GetBlob | Gets the BLOB string of the current open item within a coordinate reference system. |
| GetBlobB | Gets the BLOB of the current open item within a coordinate reference system. |
| GetBlobExtent | Gets the extents of a BLOB string, within a coordinate reference system. |
| GetOverlayThemeLegend | Gets an overlay theme legend as a BLOB string within a coordinate reference system. |
| GetSpatialReference | Gets the spatial reference for the current open item within a spanned cube in a coordinate reference system. |
| GetSpatialReferenceFromExtent |
Gets the spatial reference for the given extents within a spanned cube in a coordinate reference system. |