Layers
Layers are the major classification grouping in a database design file.
When creating a new layer, the following layer naming conventions apply. The layer name:
- may contain up to 40 characters.
- must begin with an alphanumeric character [0-9] or [a-z].
- cannot include spaces.
- can include hyphens [ - ], plus signs [ + ], underscores [ _ ], periods/dots [. ].
- can include the special characters of ÁÂÃÀÇÉÊÍÓÔÕÚÜÑ that are used in the Spanish and Portuguese languages.
The layer name is the primary access key into the digitised data file and a list of current layers is maintained in the .dgd.isix file for access purposes.
Layer names should always be chosen to help recognise the contents as this is the selection criteria for both editing and designing. Layer descriptions should also be entered and updated when required as these form the basis of summary reports. Layer names in the format 'DIG$xxxxxx' are reserved.
A list of loaded layer names displays through the Status toolbar. If the term empty is appended to the name, then it means that either the contents of the layer has been deleted or that this is a new layer and nothing has yet been created in it.
Use the list in the Status toolbar to toggle between layers, the current layer is the one in which digitised objects will be stored. The maximum number of layers that can be loaded at one time is 1000.
Layers and mapfiles may be loaded as underlays. This allows you to view data without any facility for editing.
Related information on data structures can be found in the following files:
- Overview
- Design Files
- Objects
- Coordinate Points
- Additional Data Organisation
- Structuring Your Data
